BAEL-3462 Univosity Parsers (#9222)

* BAEL-3462 CSV Univosity Example

* Added a row processor example

libraries-data-2/pom.xml

@@ -116,6 +116,11 @@
             <artifactId>slf4j-log4j12</artifactId>
             <version>${slf4j.version}</version>
         </dependency>
+        <dependency>
+            <groupId>com.univocity</groupId>
+            <artifactId>univocity-parsers</artifactId>
+            <version>${univocity.version}</version>
+        </dependency>
         <dependency>
             <groupId>org.awaitility</groupId>
             <artifactId>awaitility</artifactId>
@@ -175,6 +180,7 @@
         <assertj.version>3.6.2</assertj.version>
         <slf4j.version>1.7.25</slf4j.version>
         <awaitility.version>3.0.0</awaitility.version>
+        <univocity.version>2.8.4</univocity.version>
         <renjin.version>RELEASE</renjin.version>
         <rcaller.version>3.0</rcaller.version>
         <rserve.version>1.8.1</rserve.version>

libraries-data-2/src/main/java/com/baeldung/univocity/OutputService.java

@@ -0,0 +1,80 @@
+package com.baeldung.univocity;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.OutputStreamWriter;
+import java.io.Writer;
+import java.util.List;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.baeldung.univocity.model.Product;
+import com.univocity.parsers.common.processor.BeanWriterProcessor;
+import com.univocity.parsers.csv.CsvWriter;
+import com.univocity.parsers.csv.CsvWriterSettings;
+import com.univocity.parsers.fixed.FixedWidthFields;
+import com.univocity.parsers.fixed.FixedWidthWriter;
+import com.univocity.parsers.fixed.FixedWidthWriterSettings;
+import com.univocity.parsers.tsv.TsvWriter;
+import com.univocity.parsers.tsv.TsvWriterSettings;
+
+public class OutputService {
+    private Logger logger = LoggerFactory.getLogger(ParsingService.class);
+
+    public enum OutputType {
+        CSV, TSV, FIXED_WIDTH
+    };
+
+    public boolean writeData(List<Object[]> products, OutputType outputType, String outputPath) {
+        try (Writer outputWriter = new OutputStreamWriter(new FileOutputStream(new File(outputPath)), "UTF-8")) {
+            switch (outputType) {
+            case CSV: {
+                CsvWriter writer = new CsvWriter(outputWriter, new CsvWriterSettings());
+                writer.writeRowsAndClose(products);
+            }
+                break;
+            case TSV: {
+                TsvWriter writer = new TsvWriter(outputWriter, new TsvWriterSettings());
+                writer.writeRowsAndClose(products);
+            }
+                break;
+            case FIXED_WIDTH: {
+                FixedWidthFields fieldLengths = new FixedWidthFields(8, 30, 10);
+                FixedWidthWriterSettings settings = new FixedWidthWriterSettings(fieldLengths);
+                FixedWidthWriter writer = new FixedWidthWriter(outputWriter, settings);
+                writer.writeRowsAndClose(products);
+            }
+                break;
+            default:
+                logger.warn("Invalid OutputType: " + outputType);
+                return false;
+            }
+            return true;
+        } catch (IOException e) {
+            logger.error(e.getMessage());
+            return false;
+        }
+    }
+
+    public boolean writeBeanToFixedWidthFile(List<Product> products, String outputPath) {
+        try (Writer outputWriter = new OutputStreamWriter(new FileOutputStream(new File(outputPath)), "UTF-8")) {
+            BeanWriterProcessor<Product> rowProcessor = new BeanWriterProcessor<Product>(Product.class);
+            FixedWidthFields fieldLengths = new FixedWidthFields(8, 30, 10);
+            FixedWidthWriterSettings settings = new FixedWidthWriterSettings(fieldLengths);
+            settings.setHeaders("product_no", "description", "unit_price");
+            settings.setRowWriterProcessor(rowProcessor);
+            FixedWidthWriter writer = new FixedWidthWriter(outputWriter, settings);
+            writer.writeHeaders();
+            for (Product product : products) {
+                writer.processRecord(product);
+            }
+            writer.close();
+            return true;
+        } catch (IOException e) {
+            logger.error(e.getMessage());
+            return false;
+        }
+    }
+}

libraries-data-2/src/main/java/com/baeldung/univocity/ParsingService.java

@@ -0,0 +1,85 @@
+package com.baeldung.univocity;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.baeldung.univocity.model.Product;
+import com.univocity.parsers.common.processor.BatchedColumnProcessor;
+import com.univocity.parsers.common.processor.BeanListProcessor;
+import com.univocity.parsers.csv.CsvParser;
+import com.univocity.parsers.csv.CsvParserSettings;
+import com.univocity.parsers.fixed.FixedWidthFields;
+import com.univocity.parsers.fixed.FixedWidthParser;
+import com.univocity.parsers.fixed.FixedWidthParserSettings;
+
+public class ParsingService {
+    private Logger logger = LoggerFactory.getLogger(ParsingService.class);
+
+    public List<String[]> parseCsvFile(String relativePath) {
+        try (Reader inputReader = new InputStreamReader(new FileInputStream(new File(relativePath)), "UTF-8")) {
+            CsvParserSettings settings = new CsvParserSettings();
+            settings.setMaxCharsPerColumn(100);
+            settings.setMaxColumns(50);
+            CsvParser parser = new CsvParser(settings);
+            List<String[]> parsedRows = parser.parseAll(inputReader);
+            return parsedRows;
+        } catch (IOException e) {
+            logger.error("IOException opening file: " + relativePath + " " + e.getMessage());
+            return new ArrayList<String[]>();
+        }
+    }
+
+    public List<String[]> parseFixedWidthFile(String relativePath) {
+        try (Reader inputReader = new InputStreamReader(new FileInputStream(new File(relativePath)), "UTF-8")) {
+            FixedWidthFields fieldLengths = new FixedWidthFields(8, 30, 10);
+            FixedWidthParserSettings settings = new FixedWidthParserSettings(fieldLengths);
+
+            FixedWidthParser parser = new FixedWidthParser(settings);
+            List<String[]> parsedRows = parser.parseAll(inputReader);
+            return parsedRows;
+        } catch (IOException e) {
+            logger.error("IOException opening file: " + relativePath + " " + e.getMessage());
+            return new ArrayList<String[]>();
+        }
+    }
+
+    public List<Product> parseCsvFileIntoBeans(String relativePath) {
+        try (Reader inputReader = new InputStreamReader(new FileInputStream(new File(relativePath)), "UTF-8")) {
+            BeanListProcessor<Product> rowProcessor = new BeanListProcessor<Product>(Product.class);
+            CsvParserSettings settings = new CsvParserSettings();
+            settings.setHeaderExtractionEnabled(true);
+            settings.setProcessor(rowProcessor);
+            CsvParser parser = new CsvParser(settings);
+            parser.parse(inputReader);
+            return rowProcessor.getBeans();
+        } catch (IOException e) {
+            logger.error("IOException opening file: " + relativePath + " " + e.getMessage());
+            return new ArrayList<Product>();
+        }
+    }
+
+    public List<String[]> parseCsvFileInBatches(String relativePath) {
+        try (Reader inputReader = new InputStreamReader(new FileInputStream(new File(relativePath)), "UTF-8")) {
+            CsvParserSettings settings = new CsvParserSettings();
+            settings.setProcessor(new BatchedColumnProcessor(5) {
+                @Override
+                public void batchProcessed(int rowsInThisBatch) {
+                }
+            });
+            CsvParser parser = new CsvParser(settings);
+            List<String[]> parsedRows = parser.parseAll(inputReader);
+            return parsedRows;
+        } catch (IOException e) {
+            logger.error("IOException opening file: " + relativePath + " " + e.getMessage());
+            return new ArrayList<String[]>();
+        }
+    }
+}

libraries-data-2/src/main/java/com/baeldung/univocity/model/Product.java

@@ -0,0 +1,44 @@
+package com.baeldung.univocity.model;
+
+import com.univocity.parsers.annotations.Parsed;
+
+public class Product {
+
+    @Parsed(field = "product_no")
+    private String productNumber;
+
+    @Parsed
+    private String description;
+
+    @Parsed(field = "unit_price")
+    private float unitPrice;
+
+    public String getProductNumber() {
+        return productNumber;
+    }
+
+    public void setProductNumber(String productNumber) {
+        this.productNumber = productNumber;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public void setDescription(String description) {
+        this.description = description;
+    }
+
+    public float getUnitPrice() {
+        return unitPrice;
+    }
+
+    public void setUnitPrice(float unitPrice) {
+        this.unitPrice = unitPrice;
+    }
+
+    @Override
+    public String toString() {
+        return "Product [Product Number: " + productNumber + ", Description: " + description + ", Unit Price: " + unitPrice + "]";
+    }
+}

libraries-data-2/src/test/java/com/baeldung/univocity/ParsingServiceUnitTest.java

@@ -0,0 +1,112 @@
+package com.baeldung.univocity;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.Test;
+
+import com.baeldung.univocity.model.Product;
+
+public class ParsingServiceUnitTest {
+
+    @Test
+    public void givenCsvFile_thenParsedResultsShouldBeReturned() {
+        ParsingService parsingService = new ParsingService();
+        List<String[]> productData = parsingService.parseCsvFile("src/test/resources/productList.csv");
+        assertEquals(3, productData.size());
+        assertEquals(3, productData.get(0).length);
+        assertEquals("A8993-10", productData.get(0)[0]);
+        assertEquals("Extra large widget", productData.get(0)[1]);
+        assertEquals("35.42", productData.get(0)[2]);
+        assertEquals("D-2938-1", productData.get(1)[0]);
+        assertEquals("Winding widget \"Deluxe Model\"", productData.get(1)[1]);
+        assertEquals("245.99", productData.get(1)[2]);
+        assertEquals("R3212-32", productData.get(2)[0]);
+        assertEquals("Standard widget", productData.get(2)[1]);
+        assertEquals("2.34", productData.get(2)[2]);
+    }
+
+    @Test
+    public void givenFixedWidthFile_thenParsedResultsShouldBeReturned() {
+        ParsingService parsingService = new ParsingService();
+        List<String[]> productData = parsingService.parseFixedWidthFile("src/test/resources/productList.txt");
+        // Note: any extra spaces on the end will cause a null line to be added
+        assertEquals(3, productData.size());
+        assertEquals(3, productData.get(0).length);
+        assertEquals("A8993-10", productData.get(0)[0]);
+        assertEquals("Extra large widget", productData.get(0)[1]);
+        assertEquals("35.42", productData.get(0)[2]);
+        assertEquals("D-2938-1", productData.get(1)[0]);
+        assertEquals("Winding widget \"Deluxe Model\"", productData.get(1)[1]);
+        assertEquals("245.99", productData.get(1)[2]);
+        assertEquals("R3212-32", productData.get(2)[0]);
+        assertEquals("Standard widget", productData.get(2)[1]);
+        assertEquals("2.34", productData.get(2)[2]);
+    }
+
+    @Test
+    public void givenDataAndCsvOutputType_thenCsvFileProduced() {
+        OutputService outputService = new OutputService();
+        List<Object[]> productData = new ArrayList<>();
+        productData.add(new Object[] { "1000-3-0", "Widget No. 96", "5.67" });
+        productData.add(new Object[] { "G930-M-P", "1/4\" Wocket", ".67" });
+        productData.add(new Object[] { "8080-0-M", "No. 54 Jumbo Widget", "35.74" });
+        outputService.writeData(productData, OutputService.OutputType.CSV, "src/test/resources/outputProductList.csv");
+
+        ParsingService parsingService = new ParsingService();
+        List<String[]> writtenData = parsingService.parseCsvFile("src/test/resources/outputProductList.csv");
+        assertEquals(3, writtenData.size());
+        assertEquals(3, writtenData.get(0).length);
+    }
+
+    @Test
+    public void givenDataAndFixedWidthOutputType_thenFixedWidthFileProduced() {
+        OutputService outputService = new OutputService();
+        List<Object[]> productData = new ArrayList<>();
+        productData.add(new Object[] { "1000-3-0", "Widget No. 96", "5.67" });
+        productData.add(new Object[] { "G930-M-P", "1/4\" Wocket", ".67" });
+        productData.add(new Object[] { "8080-0-M", "No. 54 Jumbo Widget", "35.74" });
+        outputService.writeData(productData, OutputService.OutputType.FIXED_WIDTH, "src/test/resources/outputProductList.txt");
+
+        ParsingService parsingService = new ParsingService();
+        List<String[]> writtenData = parsingService.parseFixedWidthFile("src/test/resources/outputProductList.txt");
+        assertEquals(3, writtenData.size());
+        assertEquals(3, writtenData.get(0).length);
+    }
+
+    @Test
+    public void givenCsvFile_thenCsvFileParsedIntoBeans() {
+        ParsingService parsingService = new ParsingService();
+        List<Product> products = parsingService.parseCsvFileIntoBeans("src/test/resources/productListWithHeaders.csv");
+        assertEquals(2, products.size());
+        assertEquals("Product [Product Number: 99-378AG, Description: Wocket Widget #42, Unit Price: 3.56]", products.get(0)
+            .toString());
+        assertEquals("Product [Product Number: TB-333-0, Description: Turbine Widget replacement kit, Unit Price: 800.99]", products.get(1)
+            .toString());
+    }
+
+    @Test
+    public void givenLisOfProduct_thenWriteFixedWidthFile() {
+        OutputService outputService = new OutputService();
+        Product product = new Product();
+        product.setProductNumber("007-PPG0");
+        product.setDescription("3/8\" x 1\" Wocket");
+        product.setUnitPrice(45.99f);
+        List<Product> products = new ArrayList<>();
+        products.add(product);
+        outputService.writeBeanToFixedWidthFile(products, "src/test/resources/productListWithHeaders.txt");
+        ParsingService parsingService = new ParsingService();
+        List<String[]> writtenData = parsingService.parseFixedWidthFile("src/test/resources/productListWithHeaders.txt");
+        assertEquals(2, writtenData.size());
+        assertEquals(3, writtenData.get(0).length);
+    }
+
+    @Test
+    public void givenLargeCsvFile_thenParsedDataShouldBeReturned() {
+        ParsingService parsingService = new ParsingService();
+        List<String[]> productData = parsingService.parseCsvFileInBatches("src/test/resources/largeProductList.csv");
+        assertEquals(36, productData.size());
+    }
+}

libraries-data-2/src/test/resources/largeProductList.csv

@@ -0,0 +1,36 @@
+A8993-10,"Extra large widget",35.42
+D-2938-1,"Winding widget ""Deluxe Model""",245.99
+R3212-32,"Standard widget",2.34
+A8993-10,"Extra large widget",35.42
+D-2938-1,"Winding widget ""Deluxe Model""",245.99
+R3212-32,"Standard widget",2.34
+A8993-10,"Extra large widget",35.42
+D-2938-1,"Winding widget ""Deluxe Model""",245.99
+R3212-32,"Standard widget",2.34
+A8993-10,"Extra large widget",35.42
+D-2938-1,"Winding widget ""Deluxe Model""",245.99
+R3212-32,"Standard widget",2.34
+A8993-10,"Extra large widget",35.42
+D-2938-1,"Winding widget ""Deluxe Model""",245.99
+R3212-32,"Standard widget",2.34
+A8993-10,"Extra large widget",35.42
+D-2938-1,"Winding widget ""Deluxe Model""",245.99
+R3212-32,"Standard widget",2.34
+A8993-10,"Extra large widget",35.42
+D-2938-1,"Winding widget ""Deluxe Model""",245.99
+R3212-32,"Standard widget",2.34
+A8993-10,"Extra large widget",35.42
+D-2938-1,"Winding widget ""Deluxe Model""",245.99
+R3212-32,"Standard widget",2.34
+A8993-10,"Extra large widget",35.42
+D-2938-1,"Winding widget ""Deluxe Model""",245.99
+R3212-32,"Standard widget",2.34
+A8993-10,"Extra large widget",35.42
+D-2938-1,"Winding widget ""Deluxe Model""",245.99
+R3212-32,"Standard widget",2.34
+A8993-10,"Extra large widget",35.42
+D-2938-1,"Winding widget ""Deluxe Model""",245.99
+R3212-32,"Standard widget",2.34
+A8993-10,"Extra large widget",35.42
+D-2938-1,"Winding widget ""Deluxe Model""",245.99
+R3212-32,"Standard widget",2.34

libraries-data-2/src/test/resources/productList.csv

@@ -0,0 +1,3 @@
+A8993-10,"Extra large widget",35.42
+D-2938-1,"Winding widget ""Deluxe Model""",245.99
+R3212-32,"Standard widget",2.34

libraries-data-2/src/test/resources/productList.txt

@@ -0,0 +1,3 @@
+A8993-10Extra large widget            35.42     
+D-2938-1Winding widget "Deluxe Model" 245.99    
+R3212-32Standard widget               2.34      

libraries-data-2/src/test/resources/productListWithHeaders.csv

@@ -0,0 +1,3 @@
+product_no, description, unit_price
+99-378AG,Wocket Widget #42,3.56
+TB-333-0,Turbine Widget replacement kit,800.99

libraries-data-2/src/test/resources/productListWithHeaders.txt

@@ -0,0 +1,2 @@
+product_description                   unit_price
+007-PPG03/8" x 1" Wocket              45.99