Merge branch 'eugenp:master' into master

algorithms-miscellaneous-3/pom.xml

@@ -37,7 +37,7 @@
         <dependency>
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-lang3</artifactId>
-            <version>${commons.lang3.version}</version>
+            <version>${commons-lang3.version}</version>
         </dependency>
         <dependency>
             <groupId>pl.pragmatists</groupId>
@@ -63,10 +63,8 @@
     </dependencies>
 
     <properties>
-        <commons-collections4.version>4.3</commons-collections4.version>
         <guava.version>28.0-jre</guava.version>
         <retrofit.version>2.6.0</retrofit.version>
-        <commons.lang3.version>3.8.1</commons.lang3.version>
         <JUnitParams.version>1.1.0</JUnitParams.version>
     </properties>
 

apache-poi-2/.gitignore

@@ -0,0 +1,3 @@
+*.docx
+temp.xls
+temp.xlsx

apache-poi-2/README.md

@@ -0,0 +1,8 @@
+## Apache POI
+
+This module contains articles about Apache POI
+
+### Relevant Articles:
+
+- [Adding a Column to an Excel Sheet Using Apache POI](https://www.baeldung.com/java-excel-add-column)
+- More articles: [[<-- prev]](/apache-poi)

apache-poi-2/pom.xml

@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>apache-poi-2</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>apache-poi-2</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.poi</groupId>
+            <artifactId>poi-ooxml</artifactId>
+            <version>${poi.version}</version>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <poi.version>5.0.0</poi.version>
+    </properties>
+
+</project>
+

apache-poi-2/src/main/java/com/baeldung/poi/excel/newcolumn/ExcelColumn.java

@@ -0,0 +1,16 @@
+package com.baeldung.poi.excel.newcolumn;
+import org.apache.poi.ss.usermodel.CellType;
+import org.apache.poi.ss.usermodel.Row;
+import org.apache.poi.ss.usermodel.Sheet;
+import org.apache.poi.ss.usermodel.Workbook;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
+
+
+public class ExcelColumn {
+
+    public void addColumn(Sheet sheet, CellType cellType) {
+        for (Row currentRow : sheet) {
+            currentRow.createCell(currentRow.getLastCellNum(), cellType);
+        }
+    }
+}

apache-poi-2/src/main/java/com/baeldung/poi/excel/write/addimageincell/ExcelCellImageHelper.java

@@ -0,0 +1,76 @@
+package com.baeldung.poi.excel.write.addimageincell;
+
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
+import org.apache.poi.ss.usermodel.Row;
+import org.apache.poi.ss.usermodel.Sheet;
+import org.apache.poi.ss.usermodel.Workbook;
+import org.apache.poi.util.IOUtils;
+import org.apache.poi.xssf.usermodel.XSSFClientAnchor;
+import org.apache.poi.xssf.usermodel.XSSFDrawing;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
+
+/**
+ * This Helper class Add an Image to a Cell of an Excel File With apache-poi api.
+ *
+ */
+public class ExcelCellImageHelper {
+
+    public static void main(String[] args) throws IOException, InvalidFormatException {
+        try (final Workbook workbook = new XSSFWorkbook();
+            FileOutputStream saveExcel = new FileOutputStream("target/baeldung-apachepoi.xlsx");) {
+            
+            Sheet sheet = workbook.createSheet("Avengers");
+
+            XSSFDrawing drawing = (XSSFDrawing) sheet.createDrawingPatriarch();
+            XSSFClientAnchor ironManAnchor = new XSSFClientAnchor();
+            XSSFClientAnchor spiderManAnchor = new XSSFClientAnchor();
+
+            // Fill row1 data
+            Row row1 = sheet.createRow(0);
+            row1.setHeight((short) 1000);
+            row1.createCell(0)
+                .setCellValue("IRON-MAN");
+            updateCellWithImage(workbook, 1, drawing, ironManAnchor, "ironman.png");
+
+            // Fill row2 data
+            Row row2 = sheet.createRow(1);
+            row2.setHeight((short) 1000);
+            row2.createCell(0)
+                .setCellValue("SPIDER-MAN");
+            updateCellWithImage(workbook, 2, drawing, spiderManAnchor, "spiderman.png");
+
+            // Resize all columns to fit the content size
+            for (int i = 0; i < 2; i++) {
+                sheet.autoSizeColumn(i);
+            }
+            workbook.write(saveExcel);
+        }
+
+    }
+
+    /**
+     * This method position the anchor for a given rowNum and add the image correctly.
+     * @param workbook
+     * @param rowNum
+     * @param drawing
+     * @param inputImageAnchor
+     * @throws IOException
+     */
+    private static void updateCellWithImage(Workbook workbook, int rowNum, XSSFDrawing drawing, XSSFClientAnchor inputImageAnchor, String inputImageName) throws IOException {
+        InputStream inputImageStream = ExcelCellImageHelper.class.getClassLoader()
+            .getResourceAsStream(inputImageName);
+        byte[] inputImageBytes = IOUtils.toByteArray(inputImageStream);
+        int inputImagePictureID = workbook.addPicture(inputImageBytes, Workbook.PICTURE_TYPE_PNG);
+        inputImageStream.close();
+        inputImageAnchor.setCol1(1);
+        inputImageAnchor.setRow1(rowNum - 1);
+        inputImageAnchor.setCol2(2);
+        inputImageAnchor.setRow2(rowNum);
+        drawing.createPicture(inputImageAnchor, inputImagePictureID);
+    }
+
+}

apache-poi-2/src/test/java/com/baeldung/poi/excel/newcolumn/ExcelColumnUnitTest.java

@@ -0,0 +1,40 @@
+package com.baeldung.poi.excel.newcolumn;
+
+import org.apache.poi.ss.usermodel.CellType;
+import org.apache.poi.ss.usermodel.Row;
+import org.apache.poi.ss.usermodel.Sheet;
+import org.apache.poi.ss.usermodel.Workbook;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.nio.file.Paths;
+
+import static org.junit.Assert.assertEquals;
+
+public class ExcelColumnUnitTest {
+    private static final String FILE_NAME = "newColumnTest.xlsx";
+    private String fileLocation;
+
+    @Before
+    public void setup() throws URISyntaxException {
+        fileLocation = Paths.get(ClassLoader.getSystemResource(FILE_NAME).toURI()).toString();
+    }
+
+    @Test
+    public void givenExistingRows_whenAddNewColumn_thenRowColumnNumberIncreased() throws IOException {
+        Workbook workbook = new XSSFWorkbook(fileLocation);
+        Sheet sheet = workbook.getSheetAt(0);
+        Row row = sheet.getRow(0);
+        assertEquals(5, row.getLastCellNum());
+
+        ExcelColumn excelColumn = new ExcelColumn();
+        excelColumn.addColumn(sheet, CellType.STRING);
+        assertEquals(6, row.getLastCellNum());
+
+        workbook.close();
+    }
+
+}

apache-poi/README.md

@@ -15,3 +15,4 @@ This module contains articles about Apache POI
 - [Multiline Text in Excel Cell Using Apache POI](https://www.baeldung.com/apache-poi-write-multiline-text)
 - [Set Background Color of a Cell with Apache POI](https://www.baeldung.com/apache-poi-background-color)
 - [Add Borders to Excel Cells With Apache POI](https://www.baeldung.com/apache-poi-add-borders)
+- More articles: [[next -->]](/apache-poi-2)

apache-poi/src/main/java/com/baeldung/poi/excel/ExcelUtility.java

@@ -0,0 +1,75 @@
+package com.baeldung.poi.excel;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+
+import org.apache.poi.ss.usermodel.Cell;
+import org.apache.poi.ss.usermodel.CellType;
+import org.apache.poi.ss.usermodel.DateUtil;
+import org.apache.poi.ss.usermodel.Row;
+import org.apache.poi.ss.usermodel.Sheet;
+import org.apache.poi.ss.usermodel.Workbook;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
+
+public class ExcelUtility {
+    private static final String ENDLINE = System.getProperty("line.separator");
+
+    public static String readExcel(String filePath) throws IOException {
+        File file = new File(filePath);
+        FileInputStream inputStream = null;
+        StringBuilder toReturn = new StringBuilder();
+        try {
+            inputStream = new FileInputStream(file);
+            Workbook baeuldungWorkBook = new XSSFWorkbook(inputStream);
+            for (Sheet sheet : baeuldungWorkBook) {
+                toReturn.append("--------------------------------------------------------------------")
+                    .append(ENDLINE);
+                toReturn.append("Worksheet :")
+                    .append(sheet.getSheetName())
+                    .append(ENDLINE);
+                toReturn.append("--------------------------------------------------------------------")
+                    .append(ENDLINE);
+                int firstRow = sheet.getFirstRowNum();
+                int lastRow = sheet.getLastRowNum();
+                for (int index = firstRow + 1; index <= lastRow; index++) {
+                    Row row = sheet.getRow(index);
+                    toReturn.append("|| ");
+                    for (int cellIndex = row.getFirstCellNum(); cellIndex < row.getLastCellNum(); cellIndex++) {
+                        Cell cell = row.getCell(cellIndex, Row.MissingCellPolicy.CREATE_NULL_AS_BLANK);
+                        printCellValue(cell, toReturn);
+                    }
+                    toReturn.append(" ||")
+                        .append(ENDLINE);
+                }
+            }
+            inputStream.close();
+
+        } catch (IOException e) {
+            throw e;
+        }
+        return toReturn.toString();
+    }
+
+    public static void printCellValue(Cell cell, StringBuilder toReturn) {
+        CellType cellType = cell.getCellType()
+            .equals(CellType.FORMULA) ? cell.getCachedFormulaResultType() : cell.getCellType();
+        if (cellType.equals(CellType.STRING)) {
+            toReturn.append(cell.getStringCellValue())
+                .append(" | ");
+        }
+        if (cellType.equals(CellType.NUMERIC)) {
+            if (DateUtil.isCellDateFormatted(cell)) {
+                toReturn.append(cell.getDateCellValue())
+                    .append(" | ");
+            } else {
+                toReturn.append(cell.getNumericCellValue())
+                    .append(" | ");
+            }
+        }
+        if (cellType.equals(CellType.BOOLEAN)) {
+            toReturn.append(cell.getBooleanCellValue())
+                .append(" | ");
+        }
+    }
+}

apache-poi/src/main/java/com/baeldung/poi/excel/ExcelUtility.java.orig

@@ -0,0 +1,128 @@
+package com.baeldung.poi.excel;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+
+import org.apache.poi.ss.usermodel.Cell;
+import org.apache.poi.ss.usermodel.CellType;
+import org.apache.poi.ss.usermodel.DateUtil;
+import org.apache.poi.ss.usermodel.Row;
+import org.apache.poi.ss.usermodel.Sheet;
+import org.apache.poi.ss.usermodel.Workbook;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
+
+public class ExcelUtility {
+<<<<<<< HEAD
+    private static final String ENDLINE = System.getProperty("line.separator");
+
+    public static String readExcel(String filePath) throws IOException {
+        File file = new File(filePath);
+        FileInputStream inputStream = null;
+        StringBuilder toReturn = new StringBuilder();
+        try {
+            inputStream = new FileInputStream(file);
+            Workbook baeuldungWorkBook = new XSSFWorkbook(inputStream);
+            for (Sheet sheet : baeuldungWorkBook) {
+                toReturn.append("--------------------------------------------------------------------")
+                    .append(ENDLINE);
+                toReturn.append("Worksheet :")
+                    .append(sheet.getSheetName())
+                    .append(ENDLINE);
+                toReturn.append("--------------------------------------------------------------------")
+                    .append(ENDLINE);
+                int firstRow = sheet.getFirstRowNum();
+                int lastRow = sheet.getLastRowNum();
+                for (int index = firstRow + 1; index <= lastRow; index++) {
+                    Row row = sheet.getRow(index);
+                    toReturn.append("|| ");
+                    for (int cellIndex = row.getFirstCellNum(); cellIndex < row.getLastCellNum(); cellIndex++) {
+                        Cell cell = row.getCell(cellIndex, Row.MissingCellPolicy.CREATE_NULL_AS_BLANK);
+                        printCellValue(cell, toReturn);
+                    }
+                    toReturn.append(" ||")
+                        .append(ENDLINE);
+                }
+            }
+            inputStream.close();
+
+        } catch (IOException e) {
+            throw e;
+        }
+        return toReturn.toString();
+    }
+
+    public static void printCellValue(Cell cell, StringBuilder toReturn) {
+        CellType cellType = cell.getCellType()
+            .equals(CellType.FORMULA) ? cell.getCachedFormulaResultType() : cell.getCellType();
+        if (cellType.equals(CellType.STRING)) {
+            toReturn.append(cell.getStringCellValue())
+                .append(" | ");
+        }
+        if (cellType.equals(CellType.NUMERIC)) {
+            if (DateUtil.isCellDateFormatted(cell)) {
+                toReturn.append(cell.getDateCellValue())
+                    .append(" | ");
+            } else {
+                toReturn.append(cell.getNumericCellValue())
+                    .append(" | ");
+            }
+        }
+        if (cellType.equals(CellType.BOOLEAN)) {
+            toReturn.append(cell.getBooleanCellValue())
+                .append(" | ");
+        }
+    }
+=======
+	private static final String ENDLINE = System.getProperty("line.separator");
+
+	public static String readExcel(String filePath) throws IOException {
+		File file = new File(filePath);
+		FileInputStream inputStream = null;
+		StringBuilder toReturn = new StringBuilder();
+		try {
+			inputStream = new FileInputStream(file);
+			Workbook baeuldungWorkBook = new XSSFWorkbook(inputStream);
+			for (Sheet sheet : baeuldungWorkBook) {
+				toReturn.append("--------------------------------------------------------------------").append(ENDLINE);
+				toReturn.append("Worksheet :").append(sheet.getSheetName()).append(ENDLINE);
+				toReturn.append("--------------------------------------------------------------------").append(ENDLINE);
+				int firstRow = sheet.getFirstRowNum();
+				int lastRow = sheet.getLastRowNum();
+				for (int index = firstRow + 1; index <= lastRow; index++) {
+					Row row = sheet.getRow(index);
+					toReturn.append("|| ");
+					for (int cellIndex = row.getFirstCellNum(); cellIndex < row.getLastCellNum(); cellIndex++) {
+						Cell cell = row.getCell(cellIndex, Row.MissingCellPolicy.CREATE_NULL_AS_BLANK);
+						printCellValue(cell, toReturn);
+					}
+					toReturn.append(" ||").append(ENDLINE);
+				}
+			}
+			inputStream.close();
+
+		} catch (IOException e) {
+			throw e;
+		}
+		return toReturn.toString();
+	}
+
+	public static void printCellValue(Cell cell, StringBuilder toReturn) {
+		CellType cellType = cell.getCellType().equals(CellType.FORMULA) ? cell.getCachedFormulaResultType()
+				: cell.getCellType();
+		if (cellType.equals(CellType.STRING)) {
+			toReturn.append(cell.getStringCellValue()).append(" | ");
+		}
+		if (cellType.equals(CellType.NUMERIC)) {
+			if (DateUtil.isCellDateFormatted(cell)) {
+				toReturn.append(cell.getDateCellValue()).append(" | ");
+			} else {
+				toReturn.append(cell.getNumericCellValue()).append(" | ");
+			}
+		}
+		if (cellType.equals(CellType.BOOLEAN)) {
+			toReturn.append(cell.getBooleanCellValue()).append(" | ");
+		}
+	}
+>>>>>>> master
+}

apache-poi/src/test/java/com/baeldung/poi/excel/ExcelUtilityUnitTest.java

@@ -0,0 +1,72 @@
+package com.baeldung.poi.excel;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.nio.file.Paths;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+
+import org.junit.Before;
+import org.junit.Test;
+
+public class ExcelUtilityUnitTest {
+    private static final String FILE_NAME = "baeldung.xlsx";
+    private String fileLocation;
+    private static final String ENDLINE = System.getProperty("line.separator");
+    private StringBuilder output;
+
+    @Before
+    public void setupUnitTest() throws IOException, URISyntaxException, ParseException {
+        output = new StringBuilder();
+        output.append("--------------------------------------------------------------------")
+            .append(ENDLINE);
+        output.append("Worksheet :Sheet1")
+            .append(ENDLINE);
+        output.append("--------------------------------------------------------------------")
+            .append(ENDLINE);
+        output.append("|| Name1 | Surname1 | 3.55696564113E11 | ")
+            .append(new SimpleDateFormat("dd/MM/yyyy").parse("4/11/2021")
+                .toString())
+            .append(" | ‡ |  ||")
+            .append(ENDLINE);
+        output.append("|| Name2 | Surname2 | 5.646513512E9 | ")
+            .append(new SimpleDateFormat("dd/MM/yyyy").parse("4/12/2021")
+                .toString())
+            .append(" | false |  ||")
+            .append(ENDLINE);
+        output.append("|| Name3 | Surname3 | 3.55696564113E11 | ")
+            .append(new SimpleDateFormat("dd/MM/yyyy").parse("4/11/2021")
+                .toString())
+            .append(" | 7.17039641738E11 |  ||")
+            .append(ENDLINE);
+        output.append("--------------------------------------------------------------------")
+            .append(ENDLINE);
+        output.append("Worksheet :Sheet2")
+            .append(ENDLINE);
+        output.append("--------------------------------------------------------------------")
+            .append(ENDLINE);
+        output.append("|| Name4 | Surname4 | 3.55675623232E11 | 13/04/2021 |  ||")
+            .append(ENDLINE);
+
+        fileLocation = Paths.get(ClassLoader.getSystemResource(FILE_NAME)
+            .toURI())
+            .toString();
+    }
+
+    @Test
+    public void givenStringPath_whenReadExcel_thenReturnStringValue() throws IOException {
+        assertEquals(output.toString(), ExcelUtility.readExcel(fileLocation));
+
+    }
+
+    @Test
+    public void givenStringPath_whenReadExcel_thenThrowException() {
+        assertThrows(IOException.class, () -> {
+            ExcelUtility.readExcel("baeldung");
+        });
+    }
+
+}

apache-poi/src/test/java/com/baeldung/poi/excel/ExcelUtilityUnitTest.java.orig

@@ -0,0 +1,112 @@
+package com.baeldung.poi.excel;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.nio.file.Paths;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+
+import org.junit.Before;
+import org.junit.Test;
+
+public class ExcelUtilityUnitTest {
+<<<<<<< HEAD
+    private static final String FILE_NAME = "baeldung.xlsx";
+    private String fileLocation;
+    private static final String ENDLINE = System.getProperty("line.separator");
+    private StringBuilder output;
+
+    @Before
+    public void setupUnitTest() throws IOException, URISyntaxException, ParseException {
+        output = new StringBuilder();
+        output.append("--------------------------------------------------------------------")
+            .append(ENDLINE);
+        output.append("Worksheet :Sheet1")
+            .append(ENDLINE);
+        output.append("--------------------------------------------------------------------")
+            .append(ENDLINE);
+        output.append("|| Name1 | Surname1 | 3.55696564113E11 | ")
+            .append(new SimpleDateFormat("dd/MM/yyyy").parse("4/11/2021")
+                .toString())
+            .append(" | ‡ |  ||")
+            .append(ENDLINE);
+        output.append("|| Name2 | Surname2 | 5.646513512E9 | ")
+            .append(new SimpleDateFormat("dd/MM/yyyy").parse("4/12/2021")
+                .toString())
+            .append(" | false |  ||")
+            .append(ENDLINE);
+        output.append("|| Name3 | Surname3 | 3.55696564113E11 | ")
+            .append(new SimpleDateFormat("dd/MM/yyyy").parse("4/11/2021")
+                .toString())
+            .append(" | 7.17039641738E11 |  ||")
+            .append(ENDLINE);
+        output.append("--------------------------------------------------------------------")
+            .append(ENDLINE);
+        output.append("Worksheet :Sheet2")
+            .append(ENDLINE);
+        output.append("--------------------------------------------------------------------")
+            .append(ENDLINE);
+        output.append("|| Name4 | Surname4 | 3.55675623232E11 | 13/04/2021 |  ||")
+            .append(ENDLINE);
+
+        fileLocation = Paths.get(ClassLoader.getSystemResource(FILE_NAME)
+            .toURI())
+            .toString();
+    }
+
+    @Test
+    public void givenStringPath_whenReadExcel_thenReturnStringValue() throws IOException {
+        assertEquals(output.toString(), ExcelUtility.readExcel(fileLocation));
+
+    }
+
+    @Test
+    public void givenStringPath_whenReadExcel_thenThrowException() {
+        assertThrows(IOException.class, () -> {
+            ExcelUtility.readExcel("baeldung");
+        });
+    }
+=======
+	private static final String FILE_NAME = "baeldung.xlsx";
+	private String fileLocation;
+	private static final String ENDLINE = System.getProperty("line.separator");
+	private StringBuilder output;
+
+	@Before
+	public void setupUnitTest() throws IOException, URISyntaxException, ParseException {
+		output = new StringBuilder();
+		output.append("--------------------------------------------------------------------").append(ENDLINE);
+		output.append("Worksheet :Sheet1").append(ENDLINE);
+		output.append("--------------------------------------------------------------------").append(ENDLINE);
+		output.append("|| Name1 | Surname1 | 3.55696564113E11 | ").append(new SimpleDateFormat("dd/MM/yyyy").parse("4/11/2021").toString()).append(" | ‡ |  ||")
+				.append(ENDLINE);
+		output.append("|| Name2 | Surname2 | 5.646513512E9 | ").append(new SimpleDateFormat("dd/MM/yyyy").parse("4/12/2021").toString()).append(" | false |  ||")
+				.append(ENDLINE);
+		output.append("|| Name3 | Surname3 | 3.55696564113E11 | ").append(new SimpleDateFormat("dd/MM/yyyy").parse("4/11/2021").toString()).append(" | 7.17039641738E11 |  ||")
+				.append(ENDLINE);
+		output.append("--------------------------------------------------------------------").append(ENDLINE);
+		output.append("Worksheet :Sheet2").append(ENDLINE);
+		output.append("--------------------------------------------------------------------").append(ENDLINE);
+		output.append("|| Name4 | Surname4 | 3.55675623232E11 | 13/04/2021 |  ||").append(ENDLINE);
+
+		fileLocation = Paths.get(ClassLoader.getSystemResource(FILE_NAME).toURI()).toString();
+	}
+
+	@Test
+	public void givenStringPath_whenReadExcel_thenReturnStringValue() throws IOException {
+		assertEquals(output.toString(), ExcelUtility.readExcel(fileLocation));
+
+	}
+
+	@Test
+	public void givenStringPath_whenReadExcel_thenThrowException() {
+		assertThrows(IOException.class, () -> {
+			ExcelUtility.readExcel("baeldung");
+		});
+	}
+>>>>>>> master
+
+}

core-java-modules/core-java-10/pom.xml

@@ -39,7 +39,6 @@
     <properties>
         <maven.compiler.source.version>10</maven.compiler.source.version>
         <maven.compiler.target.version>10</maven.compiler.target.version>
-        <commons-collections4.version>4.1</commons-collections4.version>
     </properties>
 
 </project>

core-java-modules/core-java-11-2/pom.xml

@@ -12,6 +12,7 @@
         <groupId>com.baeldung</groupId>
         <artifactId>parent-modules</artifactId>
         <version>1.0.0-SNAPSHOT</version>
+        <relativePath>../../pom.xml</relativePath>
     </parent>
 
     <dependencies>
@@ -35,18 +36,6 @@
             <artifactId>jakarta.xml.ws-api</artifactId>
             <version>${jakarta.ws-api.version}</version>
         </dependency>
-        <dependency>
-            <groupId>com.sun.xml.ws</groupId>
-            <artifactId>jaxws-rt</artifactId>
-            <version>${jaxws-rt.version}</version>
-            <scope>runtime</scope>
-        </dependency>
-        <dependency>
-            <groupId>com.sun.xml.ws</groupId>
-            <artifactId>jaxws-ri</artifactId>
-            <version>${jaxws-ri.version}</version>
-            <type>pom</type>
-        </dependency>
     </dependencies>
 
     <build>
@@ -82,10 +71,8 @@
         <maven.compiler.target.version>11</maven.compiler.target.version>
         <guava.version>29.0-jre</guava.version>
         <mockserver.version>5.11.1</mockserver.version>
-        <jakarta.ws-api.version>3.0.0</jakarta.ws-api.version>
-        <jaxws-rt.version>3.0.0</jaxws-rt.version>
-        <jaxws-ri.version>2.3.1</jaxws-ri.version>
-        <jaxws-maven-plugin.version>2.3.2</jaxws-maven-plugin.version>
+        <jakarta.ws-api.version>3.0.1</jakarta.ws-api.version>
+        <jaxws-maven-plugin.version>3.0.2</jaxws-maven-plugin.version>
     </properties>
 
 </project>

core-java-modules/core-java-11-2/src/main/java/com/baeldung/soap/ws/client/generated/Country.java

@@ -1,10 +1,10 @@
 
 package com.baeldung.soap.ws.client.generated;
 
-import javax.xml.bind.annotation.XmlAccessType;
-import javax.xml.bind.annotation.XmlAccessorType;
-import javax.xml.bind.annotation.XmlSchemaType;
-import javax.xml.bind.annotation.XmlType;
+import jakarta.xml.bind.annotation.XmlAccessType;
+import jakarta.xml.bind.annotation.XmlAccessorType;
+import jakarta.xml.bind.annotation.XmlSchemaType;
+import jakarta.xml.bind.annotation.XmlType;
 
 
 /**

core-java-modules/core-java-11-2/src/main/java/com/baeldung/soap/ws/client/generated/CountryService.java

@@ -1,19 +1,19 @@
 
 package com.baeldung.soap.ws.client.generated;
 
-import javax.jws.WebMethod;
-import javax.jws.WebParam;
-import javax.jws.WebResult;
-import javax.jws.WebService;
-import javax.jws.soap.SOAPBinding;
-import javax.xml.bind.annotation.XmlSeeAlso;
-import javax.xml.ws.Action;
+import jakarta.jws.WebMethod;
+import jakarta.jws.WebParam;
+import jakarta.jws.WebResult;
+import jakarta.jws.WebService;
+import jakarta.jws.soap.SOAPBinding;
+import jakarta.xml.bind.annotation.XmlSeeAlso;
+import jakarta.xml.ws.Action;
 
 
 /**
  * This class was generated by the JAX-WS RI.
- * JAX-WS RI 2.3.2
- * Generated source version: 2.2
+ * JAX-WS RI 3.0.2
+ * Generated source version: 3.0
  * 
  */
 @WebService(name = "CountryService", targetNamespace = "http://server.ws.soap.baeldung.com/")

core-java-modules/core-java-11-2/src/main/java/com/baeldung/soap/ws/client/generated/CountryServiceImplService.java

@@ -4,17 +4,17 @@ package com.baeldung.soap.ws.client.generated;
 import java.net.MalformedURLException;
 import java.net.URL;
 import javax.xml.namespace.QName;
-import javax.xml.ws.Service;
-import javax.xml.ws.WebEndpoint;
-import javax.xml.ws.WebServiceClient;
-import javax.xml.ws.WebServiceException;
-import javax.xml.ws.WebServiceFeature;
+import jakarta.xml.ws.Service;
+import jakarta.xml.ws.WebEndpoint;
+import jakarta.xml.ws.WebServiceClient;
+import jakarta.xml.ws.WebServiceException;
+import jakarta.xml.ws.WebServiceFeature;
 
 
 /**
  * This class was generated by the JAX-WS RI.
- * JAX-WS RI 2.3.2
- * Generated source version: 2.2
+ * JAX-WS RI 3.0.2
+ * Generated source version: 3.0
  * 
  */
 @WebServiceClient(name = "CountryServiceImplService", targetNamespace = "http://server.ws.soap.baeldung.com/", wsdlLocation = "http://localhost:8888/ws/country?wsdl")
@@ -75,7 +75,7 @@ public class CountryServiceImplService
     /**
      * 
      * @param features
-     *     A list of {@link javax.xml.ws.WebServiceFeature} to configure on the proxy.  Supported features not in the <code>features</code> parameter will have their default values.
+     *     A list of {@link jakarta.xml.ws.WebServiceFeature} to configure on the proxy.  Supported features not in the <code>features</code> parameter will have their default values.
      * @return
      *     returns CountryService
      */

core-java-modules/core-java-11-2/src/main/java/com/baeldung/soap/ws/client/generated/Currency.java

@@ -1,15 +1,14 @@
 
 package com.baeldung.soap.ws.client.generated;
 
-import javax.xml.bind.annotation.XmlEnum;
-import javax.xml.bind.annotation.XmlType;
+import jakarta.xml.bind.annotation.XmlEnum;
+import jakarta.xml.bind.annotation.XmlType;
 
 
 /**
  * <p>Java class for currency.
  * 
  * <p>The following schema fragment specifies the expected content contained within this class.
- * <p>
  * <pre>
  * &lt;simpleType name="currency"&gt;
  *   &lt;restriction base="{http://www.w3.org/2001/XMLSchema}string"&gt;

core-java-modules/core-java-11-2/src/main/java/com/baeldung/soap/ws/client/generated/ObjectFactory.java

@@ -1,7 +1,7 @@
 
 package com.baeldung.soap.ws.client.generated;
 
-import javax.xml.bind.annotation.XmlRegistry;
+import jakarta.xml.bind.annotation.XmlRegistry;
 
 
 /**

core-java-modules/core-java-11-2/src/main/java/com/baeldung/soap/ws/client/generated/package-info.java

@@ -1,2 +1,2 @@
-@javax.xml.bind.annotation.XmlSchema(namespace = "http://server.ws.soap.baeldung.com/")
+@jakarta.xml.bind.annotation.XmlSchema(namespace = "http://server.ws.soap.baeldung.com/")
 package com.baeldung.soap.ws.client.generated;

core-java-modules/core-java-11/pom.xml

@@ -13,6 +13,8 @@
         <groupId>com.baeldung</groupId>
         <artifactId>parent-modules</artifactId>
         <version>1.0.0-SNAPSHOT</version>
+
+        <relativePath>../../pom.xml</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-8/pom.xml

@@ -43,9 +43,4 @@
         </resources>
     </build>
 
-    <properties>
-        <!-- util -->
-        <commons-collections4.version>4.1</commons-collections4.version>
-    </properties>
-
 </project>

core-java-modules/core-java-9/pom.xml

@@ -76,7 +76,6 @@
         <maven.compiler.source>1.9</maven.compiler.source>
         <maven.compiler.target>1.9</maven.compiler.target>
         <guava.version>25.1-jre</guava.version>
-        <commons-collections4.version>4.1</commons-collections4.version>
     </properties>
 
 </project>

core-java-modules/core-java-collections-2/pom.xml

@@ -44,7 +44,6 @@
 
     <properties>
         <eclipse.collections.version>7.1.0</eclipse.collections.version>
-        <commons-collections4.version>4.1</commons-collections4.version>
         <commons-exec.version>1.3</commons-exec.version>
     </properties>
 

core-java-modules/core-java-collections-3/README.md

@@ -11,7 +11,7 @@
 - [Performance of contains() in a HashSet vs ArrayList](https://www.baeldung.com/java-hashset-arraylist-contains-performance)
 - [Fail-Safe Iterator vs Fail-Fast Iterator](https://www.baeldung.com/java-fail-safe-vs-fail-fast-iterator)
 - [Quick Guide to the Java Stack](https://www.baeldung.com/java-stack)
-- [Convert an Array of Primitives to a List](https://www.baeldung.com/java-primitive-array-to-list)
 - [A Guide to BitSet in Java](https://www.baeldung.com/java-bitset)
 - [Get the First Key and Value From a HashMap](https://www.baeldung.com/java-hashmap-get-first-entry)
 - [Performance of removeAll() in a HashSet](https://www.baeldung.com/java-hashset-removeall-performance)
+- More articles: [[<-- prev]](/core-java-modules/core-java-collections-2) [[next -->]](/core-java-modules/core-java-collections-4)

core-java-modules/core-java-collections-3/src/test/java/com/baeldung/collections/stack/StackUnitTest.java

@@ -1,4 +1,4 @@
-package com.baeldung.stack;
+package com.baeldung.collections.stack;
 
 import org.junit.Test;
 

core-java-modules/core-java-collections-4/src/main/java/com/baeldung/collections/mulipletypesinmap/DynamicTypeValue.java

@@ -0,0 +1,5 @@
+package com.baeldung.collections.mulipletypesinmap;
+
+public interface DynamicTypeValue {
+    String valueDescription();
+}

core-java-modules/core-java-collections-4/src/main/java/com/baeldung/collections/mulipletypesinmap/InstantTypeValue.java

@@ -0,0 +1,24 @@
+package com.baeldung.collections.mulipletypesinmap;
+
+import java.time.Instant;
+import java.time.ZoneId;
+import java.time.format.DateTimeFormatter;
+
+public class InstantTypeValue implements DynamicTypeValue {
+    private static DateTimeFormatter FORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")
+        .withZone(ZoneId.systemDefault());
+    private Instant value;
+
+    public InstantTypeValue(Instant value) {
+        this.value = value;
+    }
+
+    @Override
+    public String valueDescription() {
+        if (value == null) {
+            return "The value is null.";
+        }
+        return String.format("The value is an instant: %s", FORMATTER.format(value));
+    }
+
+}

core-java-modules/core-java-collections-4/src/main/java/com/baeldung/collections/mulipletypesinmap/IntArrayTypeValue.java

@@ -0,0 +1,20 @@
+package com.baeldung.collections.mulipletypesinmap;
+
+import java.util.Arrays;
+
+public class IntArrayTypeValue implements DynamicTypeValue {
+    private int[] value;
+
+    public IntArrayTypeValue(int[] value) {
+        this.value = value;
+    }
+
+    @Override
+    public String valueDescription() {
+        if (value == null) {
+            return "The value is null.";
+        }
+        return String.format("The value is an array of %d integers: %s", value.length, Arrays.toString(value));
+    }
+
+}

core-java-modules/core-java-collections-4/src/main/java/com/baeldung/collections/mulipletypesinmap/IntegerTypeValue.java

@@ -0,0 +1,17 @@
+package com.baeldung.collections.mulipletypesinmap;
+
+public class IntegerTypeValue implements DynamicTypeValue {
+    private Integer value;
+
+    public IntegerTypeValue(Integer value) {
+        this.value = value;
+    }
+
+    @Override
+    public String valueDescription() {
+        if(value == null){
+            return "The value is null.";
+        }
+        return String.format("The value is a %s integer: %d", value > 0 ? "positive" : "negative", value);
+    }
+}

core-java-modules/core-java-collections-4/src/test/java/com/baeldung/multipletypesinmap/MultipleTypesInMapUnitTest.java

@@ -0,0 +1,75 @@
+package com.baeldung.multipletypesinmap;
+
+import com.baeldung.collections.mulipletypesinmap.DynamicTypeValue;
+import com.baeldung.collections.mulipletypesinmap.InstantTypeValue;
+import com.baeldung.collections.mulipletypesinmap.IntArrayTypeValue;
+import com.baeldung.collections.mulipletypesinmap.IntegerTypeValue;
+import org.junit.jupiter.api.Test;
+
+import java.time.Instant;
+import java.time.ZoneId;
+import java.time.format.DateTimeFormatter;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class MultipleTypesInMapUnitTest {
+    private static final DateTimeFormatter FORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")
+        .withZone(ZoneId.systemDefault());
+
+    private static final Integer intValue = 777;
+    private static final int[] intArray = new int[]{2, 3, 5, 7, 11, 13};
+    private static final Instant instant = Instant.now();
+
+    private static final String KEY_INT = "E1 (Integer)";
+    private static final String KEY_INT_ARRAY = "E2 (IntArray)";
+    private static final String KEY_INSTANT = "E3 (Instant)";
+
+    @Test
+    void givenThreeTypes_whenUsingRawMap_thenPrintDescription() {
+        Map<String, Object> rawMap = new HashMap<>();
+        rawMap.put(KEY_INT, intValue);
+        rawMap.put(KEY_INT_ARRAY, intArray);
+        rawMap.put(KEY_INSTANT, instant);
+
+        rawMap.forEach((k, v) -> {
+            if (v instanceof Integer) {
+                Integer theV = (Integer) v;
+                String desc = String.format("The value is a %s integer: %d", theV > 0 ? "positive" : "negative", theV);
+                System.out.println(k + " -> " + desc);
+                assertThat(k).isEqualTo(KEY_INT);
+                assertThat(desc).isEqualTo("The value is a positive integer: 777");
+            } else if (v instanceof int[]) {
+                int[] theV = (int[]) v;
+                String desc = String.format("The value is an array of %d integers: %s", theV.length, Arrays.toString(theV));
+                System.out.println(k + " -> " + desc);
+                assertThat(k).isEqualTo(KEY_INT_ARRAY);
+                assertThat(desc).isEqualTo("The value is an array of 6 integers: [2, 3, 5, 7, 11, 13]");
+            } else if (v instanceof Instant) {
+                Instant theV = (Instant) v;
+                String desc = String.format("The value is an instant: %s", FORMATTER.format(theV));
+                System.out.println(k + " -> " + desc);
+                assertThat(k).isEqualTo(KEY_INSTANT);
+                assertThat(desc).matches("^The value is an instant: \\d{4}-\\d{2}-\\d{2} \\d{2}:\\d{2}:\\d{2}");
+            } else {
+                throw new IllegalStateException("Unknown Type found.");
+            }
+        });
+    }
+
+    @Test
+    void givenThreeTypes_whenUsingAnInterface_thenPrintDescription() {
+        Map<String, DynamicTypeValue> theMap = new HashMap<>();
+        theMap.put(KEY_INT, new IntegerTypeValue(intValue));
+        theMap.put(KEY_INT_ARRAY, new IntArrayTypeValue(intArray));
+        theMap.put(KEY_INSTANT, new InstantTypeValue(instant));
+
+        theMap.forEach((k, v) -> System.out.println(k + " -> " + v.valueDescription()));
+
+        assertThat(theMap.get(KEY_INT).valueDescription()).isEqualTo("The value is a positive integer: 777");
+        assertThat(theMap.get(KEY_INT_ARRAY).valueDescription()).isEqualTo("The value is an array of 6 integers: [2, 3, 5, 7, 11, 13]");
+        assertThat(theMap.get(KEY_INSTANT).valueDescription()).matches("^The value is an instant: \\d{4}-\\d{2}-\\d{2} \\d{2}:\\d{2}:\\d{2}");
+    }
+}

core-java-modules/core-java-collections-array-list/pom.xml

@@ -22,8 +22,4 @@
         </dependency>
     </dependencies>
 
-    <properties>
-        <commons-collections4.version>4.1</commons-collections4.version>
-    </properties>
-
 </project>

core-java-modules/core-java-collections-list-2/pom.xml

@@ -28,8 +28,4 @@
         </dependency>
     </dependencies>
 
-    <properties>
-        <commons-collections4.version>4.1</commons-collections4.version>
-    </properties>
-
 </project>

core-java-modules/core-java-collections-list-3/pom.xml

@@ -54,7 +54,6 @@
     </dependencies>
 
     <properties>
-        <commons-collections4.version>4.1</commons-collections4.version>
         <trove4j.version>3.0.2</trove4j.version>
         <fastutil.version>8.1.0</fastutil.version>
         <colt.version>1.2.0</colt.version>

core-java-modules/core-java-collections-list/pom.xml

@@ -27,8 +27,4 @@
         </dependency>
     </dependencies>
 
-    <properties>
-        <commons-collections4.version>4.1</commons-collections4.version>
-    </properties>
-
 </project>

core-java-modules/core-java-collections-maps-2/pom.xml

@@ -55,7 +55,6 @@
 
     <properties>
         <streamex.version>0.6.5</streamex.version>
-        <commons-collections4.version>4.1</commons-collections4.version>
         <avaitility.version>1.7.0</avaitility.version>
         <eclipse-collections.version>8.2.0</eclipse-collections.version>
         <hppc.version>0.7.2</hppc.version>

core-java-modules/core-java-collections-maps/pom.xml

@@ -22,8 +22,4 @@
         </dependency>
     </dependencies>
 
-    <properties>
-        <commons-collections4.version>4.1</commons-collections4.version>
-    </properties>
-
 </project>

core-java-modules/core-java-collections-set/pom.xml

@@ -49,7 +49,6 @@
     <properties>
         <maven.compiler.source>11</maven.compiler.source>
         <maven.compiler.target>11</maven.compiler.target>
-        <commons-collections4.version>4.3</commons-collections4.version>
         <gson.version>2.8.5</gson.version>
     </properties>
 

core-java-modules/core-java-collections/README.md

@@ -12,4 +12,5 @@ This module contains articles about Java collections
 - [Defining a Char Stack in Java](https://www.baeldung.com/java-char-stack)
 - [Guide to the Java Queue Interface](https://www.baeldung.com/java-queue)
 - [An Introduction to Synchronized Java Collections](https://www.baeldung.com/java-synchronized-collections)
-- [[More -->]](/core-java-modules/core-java-collections-2)
+- [Convert an Array of Primitives to a List](https://www.baeldung.com/java-primitive-array-to-list)
+- More articles: [[next -->]](/core-java-modules/core-java-collections-2)

core-java-modules/core-java-collections/pom.xml

@@ -25,6 +25,11 @@
             <artifactId>jmh-generator-annprocess</artifactId>
             <version>${jmh-generator.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+        </dependency>
     </dependencies>
 
 </project>

core-java-modules/core-java-collections/src/main/java/com/baeldung/collections/convertarrayprimitives/ConvertPrimitivesArrayToList.java

@@ -1,13 +1,15 @@
-package com.baeldung.collections.iterators;
+package com.baeldung.collections.convertarrayprimitives;
 
-import java.util.List;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.List;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
-import com.google.common.primitives.Ints;
+
 import org.apache.commons.lang3.ArrayUtils;
 
+import com.google.common.primitives.Ints;
+
 public class ConvertPrimitivesArrayToList {
 
     public static void failConvert() {

core-java-modules/core-java-collections/src/test/java/com/baeldung/collections/convertarrayprimitives/ConvertPrimitivesArrayToListUnitTest.java

@@ -1,14 +1,11 @@
-package com.baeldung.collections.iterators;
-
-import java.util.List;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.stream.Collectors;
-import com.google.common.primitives.Ints;
-import org.junit.Test;
+package com.baeldung.collections.convertarrayprimitives;
 
 import static org.junit.Assert.assertEquals;
 
+import java.util.Arrays;
+
+import org.junit.Test;
+
 public class ConvertPrimitivesArrayToListUnitTest {
 
     @Test

core-java-modules/core-java-concurrency-advanced/pom.xml

@@ -56,7 +56,6 @@
     <properties>
         <guava.version>21.0</guava.version>
         <commons-math3.version>3.6.1</commons-math3.version>
-        <commons-collections4.version>4.1</commons-collections4.version>
         <collections-generic.version>4.01</collections-generic.version>
         <avaitility.version>1.7.0</avaitility.version>
     </properties>

core-java-modules/core-java-exceptions-3/src/test/java/com/baeldung/exceptions/illegalmonitorstate/IllegalMonitorStateExceptionUnitTest.java

@@ -1,11 +1,12 @@
 package com.baeldung.exceptions.illegalmonitorstate;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
 import org.junit.jupiter.api.Test;
 
-import java.time.Duration;
-
-import static org.junit.jupiter.api.Assertions.*;
-
 public class IllegalMonitorStateExceptionUnitTest {
 
     @Test
@@ -20,11 +21,11 @@ public class IllegalMonitorStateExceptionUnitTest {
         Thread senderThread = new Thread(sender, "sender-thread");
         senderThread.start();
 
-        senderThread.join(1000);
-        receiverThread.join(1000);
+        // we need to wait for the sender and receiver threads to finish
+        senderThread.join(10_000);
+        receiverThread.join(10_000);
 
-        // we need to wait for enough time so that sender has had a chance to send the data
-        assertTimeout(Duration.ofSeconds(10), () -> assertEquals("test", receiver.getMessage()));
+        assertEquals("test", receiver.getMessage());
         assertFalse(sender.hasIllegalMonitorStateExceptionOccurred());
         assertFalse(receiver.hasIllegalMonitorStateExceptionOccurred());
     }

core-java-modules/core-java-lang-oop-methods/pom.xml

@@ -2,6 +2,7 @@
 <project xmlns="http://maven.apache.org/POM/4.0.0"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-lang-oop-methods</artifactId>
     <name>core-java-lang-oop-methods</name>
@@ -33,7 +34,9 @@
     </dependencies>
 
     <properties>
-        <lombok.version>1.18.12</lombok.version>
+        <lombok.version>1.18.22</lombok.version>
+        <commons-lang.version>2.6</commons-lang.version>
+        <assertj-core.version>3.10.0</assertj-core.version>
         <equalsverifier.version>3.0.3</equalsverifier.version>
     </properties>
 

core-java-modules/core-java-lang-oop-methods/src/main/java/com/baeldung/utilities/StringUtils.java

@@ -0,0 +1,17 @@
+package com.baeldung.utilities;
+
+public final class StringUtils {
+
+    private StringUtils() {
+        throw new UnsupportedOperationException("This is a utility class and cannot be instantiated");
+    }
+
+    public static boolean isEmpty(String source) {
+        return source == null || source.length() == 0;
+    }
+
+    public static String wrap(String source, String wrapWith) {
+        return isEmpty(source) ? source : wrapWith + source + wrapWith;
+    }
+
+}

core-java-modules/core-java-lang-oop-methods/src/main/java/com/baeldung/utilities/alternatives/StringUtilsEnum.java

@@ -0,0 +1,13 @@
+package com.baeldung.utilities.alternatives;
+
+public enum StringUtilsEnum {;
+
+    public static boolean isEmpty(String source) {
+        return source == null || source.length() == 0;
+    }
+
+    public static String wrap(String source, String wrapWith) {
+        return isEmpty(source) ? source : wrapWith + source + wrapWith;
+    }
+
+}

core-java-modules/core-java-lang-oop-methods/src/main/java/com/baeldung/utilities/alternatives/StringUtilsInterface.java

@@ -0,0 +1,13 @@
+package com.baeldung.utilities.alternatives;
+
+public interface StringUtilsInterface {
+
+    static boolean isEmpty(String source) {
+        return source == null || source.length() == 0;
+    }
+
+    static String wrap(String source, String wrapWith) {
+        return isEmpty(source) ? source : wrapWith + source + wrapWith;
+    }
+
+}

core-java-modules/core-java-lang-oop-methods/src/main/java/com/baeldung/utilities/lombok/StringUtilsWithNoArgsConstructor.java

@@ -0,0 +1,17 @@
+package com.baeldung.utilities.lombok;
+
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
+
+@NoArgsConstructor(access= AccessLevel.PRIVATE)
+public final class StringUtilsWithNoArgsConstructor {
+
+    public static boolean isEmpty(String source) {
+        return source == null || source.length() == 0;
+    }
+
+    public static String wrap(String source, String wrapWith) {
+        return isEmpty(source) ? source : wrapWith + source + wrapWith;
+    }
+
+}

core-java-modules/core-java-lang-oop-methods/src/main/java/com/baeldung/utilities/lombok/StringUtilsWithUtilityClass.java

@@ -0,0 +1,16 @@
+package com.baeldung.utilities.lombok;
+
+import lombok.experimental.UtilityClass;
+
+@UtilityClass
+public class StringUtilsWithUtilityClass {
+
+    public static boolean isEmpty(String source) {
+        return source == null || source.length() == 0;
+    }
+
+    public static String wrap(String source, String wrapWith) {
+        return isEmpty(source) ? source : wrapWith + source + wrapWith;
+    }
+
+}

core-java-modules/core-java-lang-oop-methods/src/main/java/com/baeldung/utilities/warning/StringUtilsSuppressWarning.java

@@ -0,0 +1,14 @@
+package com.baeldung.utilities.warning;
+
+@SuppressWarnings("java:S1118")
+public final class StringUtilsSuppressWarning {
+
+    public static boolean isEmpty(String source) {
+        return source == null || source.length() == 0;
+    }
+
+    public static String wrap(String source, String wrapWith) {
+        return isEmpty(source) ? source : wrapWith + source + wrapWith;
+    }
+
+}

core-java-modules/core-java-lang-oop-methods/src/test/java/com/baeldung/utilities/StringUtilsUnitTest.java

@@ -0,0 +1,28 @@
+package com.baeldung.utilities;
+
+import org.junit.jupiter.api.Test;
+import static org.assertj.core.api.Assertions.*;
+
+class StringUtilsUnitTest {
+
+    @Test
+    void givenAnEmptyString_whenCallingIsEmpty_thenResultIsTrue() {
+        assertThat(StringUtils.isEmpty("")).isTrue();
+    }
+
+    @Test
+    void givenNonEmptyString_whenCallingIsEmpty_thenResultIsFalse() {
+        assertThat(StringUtils.isEmpty("asd")).isFalse();
+    }
+
+    @Test
+    void givenAnEmptyString_whenCallingWrap_thenResultIsAnEmptyString() {
+        assertThat(StringUtils.wrap("", "wrapper")).isEmpty();
+    }
+
+    @Test
+    void givenNonEmptyString_whenCallingWrap_thenResultIsWrappedString() {
+        assertThat(StringUtils.wrap("asd", "wrapper")).isEqualTo("wrapperasdwrapper");
+    }
+
+}

core-java-modules/core-java-lang-oop-methods/src/test/java/com/baeldung/utilities/alternatives/StringUtilsEnumUnitTest.java

@@ -0,0 +1,29 @@
+package com.baeldung.utilities.alternatives;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class StringUtilsEnumUnitTest {
+
+    @Test
+    void givenAnEmptyString_whenCallingIsEmpty_thenResultIsTrue() {
+        assertThat(StringUtilsEnum.isEmpty("")).isTrue();
+    }
+
+    @Test
+    void givenNonEmptyString_whenCallingIsEmpty_thenResultIsFalse() {
+        assertThat(StringUtilsEnum.isEmpty("asd")).isFalse();
+    }
+
+    @Test
+    void givenAnEmptyString_whenCallingWrap_thenResultIsAnEmptyString() {
+        assertThat(StringUtilsEnum.wrap("", "wrapper")).isEmpty();
+    }
+
+    @Test
+    void givenNonEmptyString_whenCallingWrap_thenResultIsWrappedString() {
+        assertThat(StringUtilsEnum.wrap("asd", "wrapper")).isEqualTo("wrapperasdwrapper");
+    }
+
+}

core-java-modules/core-java-lang-oop-methods/src/test/java/com/baeldung/utilities/alternatives/StringUtilsInterfaceUnitTest.java

@@ -0,0 +1,29 @@
+package com.baeldung.utilities.alternatives;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class StringUtilsInterfaceUnitTest {
+
+    @Test
+    void givenAnEmptyString_whenCallingIsEmpty_thenResultIsTrue() {
+        assertThat(StringUtilsInterface.isEmpty("")).isTrue();
+    }
+
+    @Test
+    void givenNonEmptyString_whenCallingIsEmpty_thenResultIsFalse() {
+        assertThat(StringUtilsInterface.isEmpty("asd")).isFalse();
+    }
+
+    @Test
+    void givenAnEmptyString_whenCallingWrap_thenResultIsAnEmptyString() {
+        assertThat(StringUtilsInterface.wrap("", "wrapper")).isEmpty();
+    }
+
+    @Test
+    void givenNonEmptyString_whenCallingWrap_thenResultIsWrappedString() {
+        assertThat(StringUtilsInterface.wrap("asd", "wrapper")).isEqualTo("wrapperasdwrapper");
+    }
+
+}

core-java-modules/core-java-lang-oop-methods/src/test/java/com/baeldung/utilities/lombok/StringUtilsWithNoArgsConstructorUnitTest.java

@@ -0,0 +1,29 @@
+package com.baeldung.utilities.lombok;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class StringUtilsWithNoArgsConstructorUnitTest {
+
+    @Test
+    void givenAnEmptyString_whenCallingIsEmpty_thenResultIsTrue() {
+        assertThat(StringUtilsWithNoArgsConstructor.isEmpty("")).isTrue();
+    }
+
+    @Test
+    void givenNonEmptyString_whenCallingIsEmpty_thenResultIsFalse() {
+        assertThat(StringUtilsWithNoArgsConstructor.isEmpty("asd")).isFalse();
+    }
+
+    @Test
+    void givenAnEmptyString_whenCallingWrap_thenResultIsAnEmptyString() {
+        assertThat(StringUtilsWithNoArgsConstructor.wrap("", "wrapper")).isEmpty();
+    }
+
+    @Test
+    void givenNonEmptyString_whenCallingWrap_thenResultIsWrappedString() {
+        assertThat(StringUtilsWithNoArgsConstructor.wrap("asd", "wrapper")).isEqualTo("wrapperasdwrapper");
+    }
+
+}

core-java-modules/core-java-lang-oop-methods/src/test/java/com/baeldung/utilities/lombok/StringUtilsWithUtilityClassUnitTest.java

@@ -0,0 +1,29 @@
+package com.baeldung.utilities.lombok;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class StringUtilsWithUtilityClassUnitTest {
+
+    @Test
+    void givenAnEmptyString_whenCallingIsEmpty_thenResultIsTrue() {
+        assertThat(StringUtilsWithUtilityClass.isEmpty("")).isTrue();
+    }
+
+    @Test
+    void givenNonEmptyString_whenCallingIsEmpty_thenResultIsFalse() {
+        assertThat(StringUtilsWithUtilityClass.isEmpty("asd")).isFalse();
+    }
+
+    @Test
+    void givenAnEmptyString_whenCallingWrap_thenResultIsAnEmptyString() {
+        assertThat(StringUtilsWithUtilityClass.wrap("", "wrapper")).isEmpty();
+    }
+
+    @Test
+    void givenNonEmptyString_whenCallingWrap_thenResultIsWrappedString() {
+        assertThat(StringUtilsWithUtilityClass.wrap("asd", "wrapper")).isEqualTo("wrapperasdwrapper");
+    }
+
+}

core-java-modules/core-java-lang-oop-methods/src/test/java/com/baeldung/utilities/warning/StringUtilsStringUtilsSuppressWarningUnitTest.java

@@ -0,0 +1,29 @@
+package com.baeldung.utilities.warning;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class StringUtilsStringUtilsSuppressWarningUnitTest {
+
+    @Test
+    void givenAnEmptyString_whenCallingIsEmpty_thenResultIsTrue() {
+        assertThat(StringUtilsSuppressWarning.isEmpty("")).isTrue();
+    }
+
+    @Test
+    void givenNonEmptyString_whenCallingIsEmpty_thenResultIsFalse() {
+        assertThat(StringUtilsSuppressWarning.isEmpty("asd")).isFalse();
+    }
+
+    @Test
+    void givenAnEmptyString_whenCallingWrap_thenResultIsAnEmptyString() {
+        assertThat(StringUtilsSuppressWarning.wrap("", "wrapper")).isEmpty();
+    }
+
+    @Test
+    void givenNonEmptyString_whenCallingWrap_thenResultIsWrappedString() {
+        assertThat(StringUtilsSuppressWarning.wrap("asd", "wrapper")).isEqualTo("wrapperasdwrapper");
+    }
+
+}

core-java-modules/core-java-networking-3/README.md

@@ -9,4 +9,5 @@ This module contains articles about networking in Java
 - [Connection Timeout vs. Read Timeout for Java Sockets](https://www.baeldung.com/java-socket-connection-read-timeout)
 - [Find Whether an IP Address Is in the Specified Range or Not in Java](https://www.baeldung.com/java-check-ip-address-range)
 - [Find the IP Address of a Client Connected to a Server](https://www.baeldung.com/java-client-get-ip-address)
+- [Unix Domain Socket in Java 16](https://www.baeldung.com/java-unix-domain-socket)
 - [[<-- Prev]](/core-java-modules/core-java-networking-2)

core-java-modules/core-java-networking-3/src/test/java/com/baeldung/socket/FindFreePortUnitTest.java

@@ -4,36 +4,26 @@ import org.apache.catalina.LifecycleException;
 import org.apache.catalina.startup.Tomcat;
 import org.eclipse.jetty.server.Server;
 import org.eclipse.jetty.server.ServerConnector;
-import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 import org.springframework.util.SocketUtils;
 
 import java.io.IOException;
 import java.net.ServerSocket;
 
-import static org.assertj.core.api.Assertions.*;
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.fail;
 
 public class FindFreePortUnitTest {
 
-    private static int FREE_PORT_NUMBER;
-    private static int[] FREE_PORT_RANGE;
-
-    @BeforeAll
-    public static void getExplicitFreePortNumberAndRange() {
-        try (ServerSocket serverSocket = new ServerSocket(0)) {
-            FREE_PORT_NUMBER = serverSocket.getLocalPort();
-            FREE_PORT_RANGE = new int[] {FREE_PORT_NUMBER, FREE_PORT_NUMBER + 1, FREE_PORT_NUMBER + 2};
-        } catch (IOException e) {
-            fail("No free port is available");
-        }
-    }
+    private static final int DEFAULT_RANDOM_PORT = 34307;
 
     @Test
     public void givenExplicitFreePort_whenCreatingServerSocket_thenThatPortIsAssigned() {
-        try (ServerSocket serverSocket = new ServerSocket(FREE_PORT_NUMBER)) {
+        int freePort = getFreePort();
+
+        try (ServerSocket serverSocket = new ServerSocket(freePort)) {
             assertThat(serverSocket).isNotNull();
-            assertThat(serverSocket.getLocalPort()).isEqualTo(FREE_PORT_NUMBER);
+            assertThat(serverSocket.getLocalPort()).isEqualTo(freePort);
         } catch (IOException e) {
             fail("Port is not available");
         }
@@ -41,8 +31,10 @@ public class FindFreePortUnitTest {
 
     @Test
     public void givenExplicitOccupiedPort_whenCreatingServerSocket_thenExceptionIsThrown() {
-        try (ServerSocket serverSocket = new ServerSocket(FREE_PORT_NUMBER)) {
-            new ServerSocket(FREE_PORT_NUMBER);
+        int freePort = getFreePort();
+
+        try (ServerSocket serverSocket = new ServerSocket(freePort)) {
+            new ServerSocket(freePort);
             fail("Same port cannot be used twice");
         } catch (IOException e) {
             assertThat(e).hasMessageContaining("Address already in use");
@@ -51,7 +43,7 @@ public class FindFreePortUnitTest {
 
     @Test
     public void givenExplicitPortRange_whenCreatingServerSocket_thenOnePortIsAssigned() {
-        for (int port : FREE_PORT_RANGE) {
+        for (int port : getFreePorts()) {
             try (ServerSocket serverSocket = new ServerSocket(port)) {
                 assertThat(serverSocket).isNotNull();
                 assertThat(serverSocket.getLocalPort()).isEqualTo(port);
@@ -104,11 +96,12 @@ public class FindFreePortUnitTest {
     public void givenExplicitFreePort_whenCreatingJettyServer_thenThatPortIsAssigned() throws Exception {
         Server jettyServer = new Server();
         ServerConnector serverConnector = new ServerConnector(jettyServer);
-        serverConnector.setPort(FREE_PORT_NUMBER);
+        int freePort = getFreePort();
+        serverConnector.setPort(freePort);
         jettyServer.addConnector(serverConnector);
         try {
             jettyServer.start();
-            assertThat(serverConnector.getLocalPort()).isEqualTo(FREE_PORT_NUMBER);
+            assertThat(serverConnector.getLocalPort()).isEqualTo(freePort);
         } catch (Exception e) {
             fail("Failed to start Jetty server");
         } finally {
@@ -135,10 +128,11 @@ public class FindFreePortUnitTest {
     @Test
     public void givenExplicitFreePort_whenCreatingTomcatServer_thenThatPortIsAssigned() throws Exception {
         Tomcat tomcatServer = new Tomcat();
-        tomcatServer.setPort(FREE_PORT_NUMBER);
+        int freePort = getFreePort();
+        tomcatServer.setPort(freePort);
         try {
             tomcatServer.start();
-            assertThat(tomcatServer.getConnector().getLocalPort()).isEqualTo(FREE_PORT_NUMBER);
+            assertThat(tomcatServer.getConnector().getLocalPort()).isEqualTo(freePort);
         } catch (LifecycleException e) {
             fail("Failed to start Tomcat server");
         } finally {
@@ -147,4 +141,16 @@ public class FindFreePortUnitTest {
         }
     }
 
+    private int[] getFreePorts() {
+        int freePort = getFreePort();
+        return new int[]{freePort - 1, freePort, freePort + 1};
+    }
+
+    private int getFreePort() {
+        try(ServerSocket serverSocket = new ServerSocket(0)){
+            return serverSocket.getLocalPort();
+        } catch (IOException ex){
+            return DEFAULT_RANDOM_PORT;
+        }
+    }
 }

core-java-modules/core-java-os/pom.xml

@@ -75,7 +75,6 @@
     </build>
 
     <properties>
-        <commons-collections4.version>4.1</commons-collections4.version>
         <collections-generic.version>4.01</collections-generic.version>
         <asspectj.version>1.8.9</asspectj.version>
         <maven.compiler.source>1.9</maven.compiler.source>

core-java-modules/core-java-perf/src/main/java/com/baeldung/jmx/JMXConfiguration.java

@@ -0,0 +1,10 @@
+package com.baeldung.jmx;
+
+public class JMXConfiguration {
+
+    public static void main(String[] args) {
+        while (true) {
+            // to ensure application does not terminate
+        }
+    }
+}

core-java-modules/core-java-regex/src/test/java/com/baeldung/regex/matcher/MatcherUnitTest.java

@@ -11,6 +11,9 @@ import org.junit.jupiter.api.Test;
 
 public class MatcherUnitTest {
 
+    private static final String STRING_INPUT = "test+";
+    private static final String REGEX = "\\+";
+
     @Test
     public void whenFindFourDigitWorks_thenCorrect() {
         Pattern stringPattern = Pattern.compile("\\d\\d\\d\\d");
@@ -60,4 +63,16 @@ public class MatcherUnitTest {
         assertTrue(m.matches());// matches will always return the same return
     }
 
+    @Test
+    public void whenUsingMatcher_thenReturnTrue() {
+        Pattern pattern = Pattern.compile(REGEX);
+        Matcher matcher = pattern.matcher(STRING_INPUT);
+        assertTrue(matcher.find());
+    }
+
+    @Test
+    public void whenUsingMatches_thenReturnFalse() {
+        assertFalse(Pattern.matches(REGEX, STRING_INPUT));
+    }
+
 }

core-java-modules/core-java-string-algorithms-2/README.md

@@ -13,5 +13,4 @@ This module contains articles about string-related algorithms.
 - [Remove Leading and Trailing Characters from a String](https://www.baeldung.com/java-remove-trailing-characters)
 - [Counting Words in a String with Java](https://www.baeldung.com/java-word-counting)
 - [Finding the Difference Between Two Strings in Java](https://www.baeldung.com/java-difference-between-two-strings)
-- [Check if the First Letter of a String is Uppercase](https://www.baeldung.com/java-check-first-letter-uppercase)
 - More articles: [[<-- prev]](../core-java-string-algorithms)

core-java-modules/core-java-string-algorithms-3/README.md

@@ -6,3 +6,4 @@ This module contains articles about string-related algorithms.
 
 - [Check if Two Strings are Anagrams in Java](https://www.baeldung.com/java-strings-anagrams)
 - [Email Validation in Java](https://www.baeldung.com/java-email-validation-regex)
+- [Check if the First Letter of a String is Uppercase](https://www.baeldung.com/java-check-first-letter-uppercase)

core-java-modules/core-java-string-algorithms-3/pom.xml

@@ -49,8 +49,8 @@
     </build>
 
     <properties>
-        <guava.version>28.1-jre</guava.version>
+        <guava.version>31.0.1-jre</guava.version>
         <validator.version>1.7</validator.version>
     </properties>
 
-</project>
+</project>

core-java-modules/core-java-string-algorithms-3/src/test/java/com/baeldung/isuppercase/StringFirstCharacterUppercaseUnitTest.java

@@ -1,15 +1,12 @@
 package com.baeldung.isuppercase;
 
-import com.google.common.base.Ascii;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.TestInstance;
-
-import static org.hamcrest.MatcherAssert.assertThat;
-import static org.hamcrest.Matchers.matchesPattern;
+import com.google.common.base.Ascii;
 
 @TestInstance(TestInstance.Lifecycle.PER_CLASS)
-public class StringFirstCharacterUppercase {
+public class StringFirstCharacterUppercaseUnitTest {
 
     @Test
     public void givenString_whenCheckingWithCharacterIsUpperCase_thenStringCapitalized() {
@@ -21,7 +18,8 @@ public class StringFirstCharacterUppercase {
     public void givenString_whenCheckingWithRegex_thenStringCapitalized() {
         String example = "Katie";
         String regEx = "[A-Z]\\w*";
-        assertThat(example, matchesPattern(regEx));
+
+        Assertions.assertTrue(example.matches(regEx));
     }
 
     @Test

core-java-modules/core-java-string-conversions-2/README.md

@@ -9,4 +9,5 @@ This module contains articles about string conversions from/to another type.
 - [Converting String to BigDecimal in Java](https://www.baeldung.com/java-string-to-bigdecimal)
 - [Converting String to BigInteger in Java](https://www.baeldung.com/java-string-to-biginteger)
 - [Convert a String to Camel Case](https://www.baeldung.com/java-string-to-camel-case)
+- [Convert a ByteBuffer to String]
 - More articles: [[<-- prev]](/core-java-string-conversions)

core-java-modules/core-java-string-conversions-2/src/test/java/com/baeldung/bytebuffertostring/ByteArrayToStringUnitTest.java

@@ -0,0 +1,44 @@
+package com.baeldung.bytebuffertostring;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.nio.ByteBuffer;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+
+import org.junit.Test;
+
+public class ByteArrayToStringUnitTest {
+    private static Charset charset = StandardCharsets.UTF_8;
+    private static final String content = "baeldung";
+
+    @Test
+    public void convertUsingNewStringFromBufferArray_thenOK() {
+        // Allocate a ByteBuffer
+        ByteBuffer byteBuffer = ByteBuffer.wrap(content.getBytes());
+        if (byteBuffer.hasArray()) {
+            String newContent = new String(byteBuffer.array(), charset);
+            assertEquals(content, newContent);
+        }
+    }
+
+    @Test
+    public void convertUsingNewStringFromByteBufferGetBytes_thenOK() {
+        // Allocate a ByteBuffer
+        ByteBuffer byteBuffer = ByteBuffer.wrap(content.getBytes());
+        byte[] bytes = new byte[byteBuffer.remaining()];
+        byteBuffer.get(bytes);
+        String newContent = new String(bytes, charset);
+        assertEquals(content, newContent);
+    }
+
+    @Test
+    public void convertUsingCharsetDecode_thenOK() {
+        // Allocate a ByteBuffer
+        ByteBuffer byteBuffer = ByteBuffer.wrap(content.getBytes());
+        String newContent = charset.decode(byteBuffer)
+            .toString();
+        assertEquals(content, newContent);
+    }
+
+}

core-java-modules/core-java-string-operations-2/src/test/java/com/baeldung/hexToAscii/README.md

@@ -1,2 +0,0 @@
-### Relevant Articles:
-- [Convert Hex to ASCII in Java](http://www.baeldung.com/java-convert-hex-to-ascii)

core-java-modules/core-java-string-operations-4/README.md

@@ -2,4 +2,5 @@
 
 - [Ignoring Commas in Quotes When Splitting a Comma-separated String](https://www.baeldung.com/java-split-string-commas)
 - [Compare Strings While Ignoring Whitespace in Java](https://www.baeldung.com/java-compare-string-whitespace)
+- [Concatenating Null Strings in Java](https://www.baeldung.com/java-concat-null-string)
 

core-java-modules/core-java-string-operations-4/src/main/java/com/baeldung/concatenation/ConcatenatingNull.java

@@ -0,0 +1,86 @@
+package com.baeldung.concatenation;
+
+import java.util.StringJoiner;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+public class ConcatenatingNull {
+
+    public static void main(String[] args) {
+        String[] values = { "Java ", null, "", "is ", "great!" };
+
+        concatenateUsingPlusOperator(values);
+        concatenateUsingHelperMethod(values);
+        concatenateUsingStringBuilder(values);
+        concatenateUsingJoin(values);
+        concatenateUsingStringJoiner(values);
+        concatenateUsingCollectorsJoining(values);
+        concatenateUsingStringConcat(values);
+    }
+
+    public static String concatenateUsingStringConcat(String[] values) {
+        String result = "";
+
+        for (String value : values) {
+            result = result.concat(getNonNullString(value));
+        }
+
+        return result;
+    }
+
+    public static String concatenateUsingCollectorsJoining(String[] values) {
+        String result = Stream.of(values).filter(value -> null != value).collect(Collectors.joining(""));
+
+        return result;
+    }
+
+    public static String concatenateUsingStringJoiner(String[] values) {
+        StringJoiner result = new StringJoiner("");
+
+        for (String value : values) {
+            result = result.add(getNonNullString(value));
+        }
+
+        return result.toString();
+    }
+
+    public static String concatenateUsingJoin(String[] values) {
+        String result = String.join("", values);
+
+        return result;
+    }
+
+    public static String concatenateUsingStringBuilder(String[] values) {
+        StringBuilder result = new StringBuilder();
+
+        for (String value : values) {
+            result = result.append(getNonNullString(value));
+        }
+
+        return result.toString();
+    }
+
+    public static String concatenateUsingHelperMethod(String[] values) {
+        String result = "";
+
+        for (String value : values) {
+            result = result + getNonNullString(value);
+        }
+
+        return result;
+    }
+
+    public static String concatenateUsingPlusOperator(String[] values) {
+        String result = "";
+
+        for (String value : values) {
+            result = result + (value == null ? "" : value);
+        }
+
+        return result;
+    }
+
+    private static String getNonNullString(String value) {
+        return value == null ? "" : value;
+    }
+}

core-java-modules/core-java-string-operations-4/src/test/java/com/baeldung/concatenation/ConcatenatingNullUnitTest.java

@@ -0,0 +1,59 @@
+package com.baeldung.concatenation;
+
+import static com.baeldung.concatenation.ConcatenatingNull.concatenateUsingCollectorsJoining;
+import static com.baeldung.concatenation.ConcatenatingNull.concatenateUsingHelperMethod;
+import static com.baeldung.concatenation.ConcatenatingNull.concatenateUsingJoin;
+import static com.baeldung.concatenation.ConcatenatingNull.concatenateUsingPlusOperator;
+import static com.baeldung.concatenation.ConcatenatingNull.concatenateUsingStringBuilder;
+import static com.baeldung.concatenation.ConcatenatingNull.concatenateUsingStringConcat;
+import static com.baeldung.concatenation.ConcatenatingNull.concatenateUsingStringJoiner;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class ConcatenatingNullUnitTest {
+
+    String[] values = { "Java ", null, "", "is ", "great!" };
+
+    @Test
+    public void givenStringElementsWithNull_whenConcatenatedUsingPlus_thenNullIsIgnored() {
+        String result = concatenateUsingPlusOperator(values);
+        assertEquals("Java is great!", result);
+    }
+
+    @Test
+    public void givenStringElementsWithNull_whenConcatenatedUsingHelperMethod_thenNullIsIgnored() {
+        String result = concatenateUsingHelperMethod(values);
+        assertEquals("Java is great!", result);
+    }
+
+    @Test
+    public void givenStringElementsWithNull_whenConcatenatedUsingStringBuilder_thenNullIsIgnored() {
+        String result = concatenateUsingStringBuilder(values);
+        assertEquals("Java is great!", result);
+    }
+
+    @Test
+    public void givenStringElementsWithNull_whenConcatenatedUsingJoin_thenNullIsNotIgnored() {
+        String result = concatenateUsingJoin(values);
+        assertEquals("Java nullis great!", result);
+    }
+
+    @Test
+    public void givenStringElementsWithNull_whenConcatenatedUsingStringJoiner_thenNullIsIgnored() {
+        String result = concatenateUsingStringJoiner(values);
+        assertEquals("Java is great!", result);
+    }
+
+    @Test
+    public void givenStringElementsWithNull_whenConcatenatedUsingCollectorsJoining_thenNullIsIgnored() {
+        String result = concatenateUsingCollectorsJoining(values);
+        assertEquals("Java is great!", result);
+    }
+
+    @Test
+    public void givenStringElementsWithNull_whenConcatenatedUsingStringConcat_thenNullIsIgnored() {
+        String result = concatenateUsingStringConcat(values);
+        assertEquals("Java is great!", result);
+    }
+}

core-java-modules/core-java-time-measurements/pom.xml

@@ -38,15 +38,15 @@
             <version>${asspectj.version}</version>
         </dependency>
         <dependency>
-            <groupId>org.powermock</groupId>
-            <artifactId>powermock-module-junit4</artifactId>
-            <version>${powermock.version}</version>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-inline</artifactId>
+            <version>${mockito-inline.version}</version>
             <scope>test</scope>
         </dependency>
         <dependency>
-            <groupId>org.powermock</groupId>
-            <artifactId>powermock-api-mockito2</artifactId>
-            <version>${powermock.version}</version>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <version>${mockito-inline.version}</version>
             <scope>test</scope>
         </dependency>
         <dependency>
@@ -82,10 +82,10 @@
     <properties>
         <commons-math3.version>3.6.1</commons-math3.version>
         <joda.version>2.10</joda.version>
-        <lombok.version>1.18.12</lombok.version>
+        <lombok.version>1.18.22</lombok.version>
         <asspectj.version>1.8.9</asspectj.version>
-        <powermock.version>2.0.7</powermock.version>
         <jmockit.version>1.44</jmockit.version>
+        <mockito-inline.version>4.0.0</mockito-inline.version>
     </properties>
 
 </project>

core-java-modules/core-java-time-measurements/src/test/java/com/baeldung/time/InstantUnitTest.java

@@ -1,20 +1,15 @@
 package com.baeldung.time;
 
 import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.powermock.core.classloader.annotations.PrepareForTest;
-import org.powermock.modules.junit4.PowerMockRunner;
+import org.mockito.MockedStatic;
 
 import java.time.Clock;
 import java.time.Instant;
 import java.time.ZoneId;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.powermock.api.mockito.PowerMockito.mockStatic;
-import static org.powermock.api.mockito.PowerMockito.when;
+import static org.mockito.Mockito.mockStatic;
 
-@RunWith(PowerMockRunner.class)
-@PrepareForTest({ Instant.class })
 public class InstantUnitTest {
 
     @Test
@@ -22,12 +17,12 @@ public class InstantUnitTest {
         String instantExpected = "2014-12-22T10:15:30Z";
         Clock clock = Clock.fixed(Instant.parse(instantExpected), ZoneId.of("UTC"));
         Instant instant = Instant.now(clock);
-        mockStatic(Instant.class);
-        when(Instant.now()).thenReturn(instant);
 
-        Instant now = Instant.now();
-
-        assertThat(now.toString()).isEqualTo(instantExpected);
+        try (MockedStatic<Instant> mockedStatic = mockStatic(Instant.class)) {
+            mockedStatic.when(Instant::now).thenReturn(instant);
+            Instant now = Instant.now();
+            assertThat(now.toString()).isEqualTo(instantExpected);
+        }
     }
 
     @Test

core-java-modules/core-java-time-measurements/src/test/java/com/baeldung/time/LocalDateTimeUnitTest.java

@@ -1,9 +1,6 @@
 package com.baeldung.time;
 
 import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.powermock.core.classloader.annotations.PrepareForTest;
-import org.powermock.modules.junit4.PowerMockRunner;
 
 import java.time.Clock;
 import java.time.Instant;
@@ -11,11 +8,7 @@ import java.time.LocalDateTime;
 import java.time.ZoneId;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.mockito.Mockito.when;
-import static org.powermock.api.mockito.PowerMockito.mockStatic;
 
-@RunWith(PowerMockRunner.class)
-@PrepareForTest({ LocalDateTime.class })
 public class LocalDateTimeUnitTest {
 
     @Test

gson/pom.xml

@@ -61,10 +61,7 @@
     </build>
 
     <properties>
-        <!-- marshalling -->
         <gson.version>2.8.0</gson.version>
-        <!-- util -->
-        <commons-collections4.version>4.1</commons-collections4.version>
         <joda-time.version>2.9.6</joda-time.version>
     </properties>
 

guava-modules/guava-collections-list/pom.xml

@@ -45,9 +45,6 @@
     </build>
 
     <properties>
-        <!-- util -->
-        <commons-collections4.version>4.1</commons-collections4.version>
-        <!-- testing -->
         <java-hamcrest.version>2.0.0.0</java-hamcrest.version>
     </properties>
 

guava-modules/guava-collections/pom.xml

@@ -50,10 +50,7 @@
     </build>
 
     <properties>
-        <!-- util -->
-        <commons-collections4.version>4.1</commons-collections4.version>
         <jool.version>0.9.12</jool.version>
-        <!-- testing -->
         <java-hamcrest.version>2.0.0.0</java-hamcrest.version>
     </properties>
 

jackson-modules/jackson-conversions-2/README.md

@@ -11,4 +11,5 @@ This module contains articles about Jackson conversions.
 - [Jackson Streaming API](https://www.baeldung.com/jackson-streaming-api)
 - [Jackson: java.util.LinkedHashMap cannot be cast to X](https://www.baeldung.com/jackson-linkedhashmap-cannot-be-cast)
 - [Deserialize Snake Case to Camel Case With Jackson](https://www.baeldung.com/jackson-deserialize-snake-to-camel-case)
+- [Serialize and Deserialize Booleans as Integers With Jackson](https://www.baeldung.com/jackson-booleans-as-integers)
 - More articles: [[<-- prev]](../jackson-conversions)

java-collections-conversions/pom.xml

@@ -38,8 +38,4 @@
         </resources>
     </build>
 
-    <properties>
-        <commons-collections4.version>4.4</commons-collections4.version>
-    </properties>
-
 </project>

java-collections-maps-3/pom.xml

@@ -30,7 +30,6 @@
     </dependencies>
 
     <properties>
-        <commons-collections4.version>4.1</commons-collections4.version>
         <spring.version>5.2.5.RELEASE</spring.version>
     </properties>
 

json-2/README.md

@@ -8,3 +8,5 @@ This module contains articles about JSON.
 - [Introduction to Moshi Json](https://www.baeldung.com/java-json-moshi)
 - [Hypermedia Serialization With JSON-LD](https://www.baeldung.com/json-linked-data)
 - [Generate a Java Class From JSON](https://www.baeldung.com/java-generate-class-from-json)
+- [A Guide to FastJson](https://www.baeldung.com/fastjson)
+- More Articles: [[<-- prev]](/json)

json-2/pom.xml

@@ -14,6 +14,11 @@
     </parent>
 
     <dependencies>
+        <dependency>
+            <groupId>com.alibaba</groupId>
+            <artifactId>fastjson</artifactId>
+            <version>${fastjson.version}</version>
+        </dependency>
         <dependency>
             <groupId>org.jsonschema2pojo</groupId>
             <artifactId>jsonschema2pojo-core</artifactId>
@@ -142,6 +147,7 @@
     <properties>
         <jsoniter.version>0.9.23</jsoniter.version>
         <moshi.version>1.9.2</moshi.version>
+        <fastjson.version>1.2.21</fastjson.version>
     </properties>
 
 </project>

json-2/src/test/java/com/baeldung/fastjson/FastJsonUnitTest.java

@@ -1,4 +1,4 @@
-package fast_json;
+package com.baeldung.fastjson;
 
 import com.alibaba.fastjson.JSON;
 import com.alibaba.fastjson.JSONArray;

json-2/src/test/java/com/baeldung/fastjson/Person.java

@@ -1,4 +1,4 @@
-package fast_json;
+package com.baeldung.fastjson;
 
 import com.alibaba.fastjson.annotation.JSONField;
 

json/README.md

@@ -4,7 +4,6 @@ This module contains articles about JSON.
 
 ### Relevant Articles:
 - [Introduction to JSON Schema in Java](https://www.baeldung.com/introduction-to-json-schema-in-java)
-- [A Guide to FastJson](https://www.baeldung.com/fastjson)
 - [Introduction to JSONForms](https://www.baeldung.com/introduction-to-jsonforms)
 - [Introduction to JsonPath](https://www.baeldung.com/guide-to-jayway-jsonpath)
 - [Introduction to JSON-Java (org.json)](https://www.baeldung.com/java-org-json)
@@ -14,3 +13,4 @@ This module contains articles about JSON.
 - [Iterating Over an Instance of org.json.JSONObject](https://www.baeldung.com/jsonobject-iteration)
 - [Escape JSON String in Java](https://www.baeldung.com/java-json-escaping)
 - [Reducing JSON Data Size](https://www.baeldung.com/json-reduce-data-size)
+- More Articles: [[next -->]](/json-2)

json/pom.xml

@@ -26,11 +26,6 @@
                 </exclusion>
             </exclusions>
         </dependency>
-        <dependency>
-            <groupId>com.alibaba</groupId>
-            <artifactId>fastjson</artifactId>
-            <version>${fastjson.version}</version>
-        </dependency>
         <dependency>
             <groupId>org.json</groupId>
             <artifactId>json</artifactId>
@@ -72,9 +67,7 @@
 
     <properties>
         <everit.json.schema.version>1.4.1</everit.json.schema.version>
-        <fastjson.version>1.2.21</fastjson.version>
         <jsonb-api.version>1.0</jsonb-api.version>
-        <commons-collections4.version>4.1</commons-collections4.version>
         <yasson.version>1.0.1</yasson.version>
         <json.version>20171018</json.version>
         <gson.version>2.8.5</gson.version>

libraries-6/pom.xml

@@ -146,7 +146,6 @@
         <renjin.version>3.5-beta72</renjin.version>
         <rcaller.version>3.0</rcaller.version>
         <rserve.version>1.8.1</rserve.version>
-        <commons-collections4.version>4.4</commons-collections4.version>
         <libphonenumber.version>8.12.9</libphonenumber.version>
         <org.modelmapper.version>2.4.4</org.modelmapper.version>
     </properties>

libraries-apache-commons-collections/pom.xml

@@ -16,7 +16,7 @@
         <dependency>
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-collections4</artifactId>
-            <version>${commons.collections.version}</version>
+            <version>${commons-collections4.version}</version>
         </dependency>
         <dependency>
             <groupId>org.hamcrest</groupId>
@@ -27,7 +27,6 @@
     </dependencies>
 
     <properties>
-        <commons.collections.version>4.1</commons.collections.version>
         <org.hamcrest.java-hamcrest.version>2.0.0.0</org.hamcrest.java-hamcrest.version>
     </properties>
 

logging-modules/logback/pom.xml

@@ -74,4 +74,40 @@
         <javax.activation.version>1.1.1</javax.activation.version>
     </properties>
 
+    <profiles>
+        <profile>
+            <id>integration-lite-first</id>
+
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-surefire-plugin</artifactId>
+                        <configuration>
+                            <systemPropertyVariables>
+                                <logback.configurationFile>${project.basedir}/src/test/resources/logback-test.xml</logback.configurationFile>
+                            </systemPropertyVariables>
+                        </configuration>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+        <profile>
+            <id>integration-lite-second</id>
+
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-surefire-plugin</artifactId>
+                        <configuration>
+                            <systemPropertyVariables>
+                                <logback.configurationFile>${project.basedir}/src/test/resources/logback-test.xml</logback.configurationFile>
+                            </systemPropertyVariables>
+                        </configuration>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+    </profiles>
 </project>

persistence-modules/java-jpa-3/README.md

@@ -13,5 +13,4 @@ This module contains articles about the Java Persistence API (JPA) in Java.
 - [Returning an Auto-Generated Id with JPA](https://www.baeldung.com/jpa-get-auto-generated-id)
 - [How to Return Multiple Entities In JPA Query](https://www.baeldung.com/jpa-return-multiple-entities)
 - [Defining Unique Constraints in JPA](https://www.baeldung.com/jpa-unique-constraints)
-- [How to Check Field Existence in MongoDB?](https://www.baeldung.com/mongodb-check-field-exists)
 - [Connecting to a Specific Schema in JDBC](https://www.baeldung.com/jdbc-connect-to-schema)

persistence-modules/java-mongodb/README.md

@@ -11,3 +11,4 @@ This module contains articles about MongoDB in Java.
 - [Introduction to Morphia – Java ODM for MongoDB](https://www.baeldung.com/mongodb-morphia)
 - [MongoDB Aggregations Using Java](https://www.baeldung.com/java-mongodb-aggregations)
 - [BSON to JSON Document Conversion in Java](https://www.baeldung.com/java-convert-bson-to-json)
+- [How to Check Field Existence in MongoDB?](https://www.baeldung.com/mongodb-check-field-exists)

persistence-modules/spring-boot-persistence/README.md

@@ -7,5 +7,4 @@
 - [Resolving “Failed to Configure a DataSource” Error](https://www.baeldung.com/spring-boot-failed-to-configure-data-source)
 - [Hibernate Field Naming with Spring Boot](https://www.baeldung.com/hibernate-field-naming-spring-boot)
 - [Spring Boot with Hibernate](https://www.baeldung.com/spring-boot-hibernate)
-- [A Guide to Spring AbstractRoutingDatasource](https://www.baeldung.com/spring-abstract-routing-data-source)
-- More articles: [[more -->]](../spring-boot-persistence-2)
+- More articles: [[more -->]](../spring-boot-persistence-2)

persistence-modules/spring-jpa/README.md

@@ -5,7 +5,6 @@
 - [JPA Pagination](https://www.baeldung.com/jpa-pagination)
 - [Sorting with JPA](https://www.baeldung.com/jpa-sort)
 - [Self-Contained Testing Using an In-Memory Database](https://www.baeldung.com/spring-jpa-test-in-memory-database)
-- [Obtaining Auto-generated Keys in Spring JDBC](https://www.baeldung.com/spring-jdbc-autogenerated-keys)
 - [Spring Data Annotations](http://www.baeldung.com/spring-data-annotations)
 - [A Guide to Spring AbstractRoutingDatasource](https://www.baeldung.com/spring-abstract-routing-data-source)
 - More articles: [[next -->]](/spring-jpa-2)

pom.xml

@@ -1433,6 +1433,7 @@
         <jmh-core.version>1.33</jmh-core.version>
         <jmh-generator.version>1.33</jmh-generator.version>
         <maven-failsafe-plugin.version>2.21.0</maven-failsafe-plugin.version>
+        <commons-collections4.version>4.4</commons-collections4.version>
         <commons-io.version>2.11.0</commons-io.version>
         <commons-lang.version>2.6</commons-lang.version>
         <commons-lang3.version>3.12.0</commons-lang3.version>