Fastexcel

apache-poi/pom.xml

@@ -30,6 +30,16 @@
                 </exclusion>
             </exclusions>
         </dependency>
+        <dependency>
+            <groupId>org.dhatim</groupId>
+            <artifactId>fastexcel</artifactId>
+            <version>${fastexcel.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.dhatim</groupId>
+            <artifactId>fastexcel-reader</artifactId>
+            <version>${fastexcel.version}</version>
+        </dependency>
     </dependencies>
 
     <build>
@@ -52,6 +62,7 @@
     <properties>
         <poi.version>5.2.0</poi.version>
         <jexcel.version>1.0.6</jexcel.version>
+        <fastexcel.version>0.15.3</fastexcel.version>
         <maven.resources.plugin.version>3.2.0</maven.resources.plugin.version>
     </properties>
 

apache-poi/src/main/java/com/baeldung/fastexcel/FastexcelHelper.java

@@ -0,0 +1,64 @@
+package com.baeldung.fastexcel;
+
+import org.dhatim.fastexcel.Workbook;
+import org.dhatim.fastexcel.Worksheet;
+import org.dhatim.fastexcel.reader.Cell;
+import org.dhatim.fastexcel.reader.ReadableWorkbook;
+import org.dhatim.fastexcel.reader.Row;
+import org.dhatim.fastexcel.reader.Sheet;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Stream;
+
+public class FastexcelHelper {
+
+    public Map<Integer, List<String>> readExcel(String fileLocation) throws IOException {
+        Map<Integer, List<String>> data = new HashMap<>();
+
+        try (FileInputStream file = new FileInputStream(fileLocation); ReadableWorkbook wb = new ReadableWorkbook(file)) {
+            Sheet sheet = wb.getFirstSheet();
+            try (Stream<Row> rows = sheet.openStream()) {
+                rows.forEach(r -> {
+                    data.put(r.getRowNum(), new ArrayList<>());
+
+                    for (Cell cell : r) {
+                        data.get(r.getRowNum()).add(cell.getRawValue());
+                    }
+                });
+            }
+        }
+
+        return data;
+    }
+
+    public void writeExcel() throws IOException {
+        File currDir = new File(".");
+        String path = currDir.getAbsolutePath();
+        String fileLocation = path.substring(0, path.length() - 1) + "fastexcel.xlsx";
+
+        try (OutputStream os = Files.newOutputStream(Paths.get(fileLocation)); Workbook wb = new Workbook(os, "MyApplication", "1.0")) {
+            Worksheet ws = wb.newWorksheet("Sheet 1");
+
+            ws.width(0, 25);
+            ws.width(1, 15);
+
+
+            ws.range(0, 0, 0, 1).style().fontName("Arial").fontSize(16).bold().fillColor("3366FF").set();
+            ws.value(0, 0, "Name");
+            ws.value(0, 1, "Age");
+
+            ws.range(1, 0, 1, 1).style().wrapText(true).set();
+            ws.value(2, 0, "John Smith");
+            ws.value(2, 1, 20L);
+        }
+    }
+}

apache-poi/src/test/java/com/baeldung/fastexcel/FastexcelIntegrationTest.java

@@ -0,0 +1,50 @@
+package com.baeldung.fastexcel;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.List;
+import java.util.Map;
+
+import static org.junit.Assert.assertEquals;
+
+public class FastexcelIntegrationTest {
+
+    private FastexcelHelper fastexcelHelper;
+    private static String FILE_NAME = "fastexcel.xlsx";
+    private String fileLocation;
+
+    @Before
+    public void generateExcelFile() throws IOException {
+
+        File currDir = new File(".");
+        String path = currDir.getAbsolutePath();
+        fileLocation = path.substring(0, path.length() - 1) + FILE_NAME;
+        System.out.println(fileLocation);
+
+        fastexcelHelper = new FastexcelHelper();
+        fastexcelHelper.writeExcel();
+    }
+
+    @Test
+    public void whenParsingExcelFile_thenCorrect() throws IOException {
+        Map<Integer, List<String>> data = fastexcelHelper.readExcel(fileLocation);
+
+        assertEquals("Name", data.get(1).get(0));
+        assertEquals("Age", data.get(1).get(1));
+
+        assertEquals("John Smith", data.get(3).get(0));
+        assertEquals("20", data.get(3).get(1));
+    }
+
+    @After
+    public void cleanup() {
+        File testFile = new File(fileLocation);
+        if (testFile.exists()) {
+            testFile.delete();
+        }
+    }
+}