Added new methods to convert Excel to CSV

Author: MBenincasa

src/main/java/io/github/mbenincasa/javaexcelutils/samples/convertExcelFileToCsvFile/Main.java

@@ -3,6 +3,7 @@
 import io.github.mbenincasa.javaexcelutils.tools.Converter;
 
 import java.io.File;
+import java.util.Map;
 
 public class Main {
 
@@ -12,8 +13,11 @@ public static void main(String[] args) {
 
         try {
             System.out.println("Start the conversion...");
-            File csvFile = Converter.excelToCsv(excelFile, "./src/main/resources/", "employee", "Employee");
-            System.out.println("The file is ready. Path: " + csvFile.getAbsolutePath());
+            Map<String, File> fileMap = Converter.excelToCsvFile(excelFile, "./src/main/resources/");
+            System.out.println("... completed");
+            for (Map.Entry<String, File> entry : fileMap.entrySet()) {
+                System.out.println("The file is ready. Path: " + entry.getValue().getAbsolutePath());
+            }
         } catch (Exception e) {
             System.err.println("There was an error. Check the console");
             throw new RuntimeException(e);

src/main/java/io/github/mbenincasa/javaexcelutils/tools/Converter.java

@@ -605,6 +605,7 @@ public static Map<String, Stream<?>> excelStreamToObjects(InputStream inputStrea
     /**
      * Convert an Excel file into a CSV file<p>
      * The default path is that of the temporary folder. By default, the first sheet is chosen and the filename will be the same as the input file if not specified
+     * @deprecated since version 0.4.0
      * @param fileInput The input Excel file that will be converted into a CSV file
      * @return A CSV file that contains the same lines as the Excel file
      * @throws FileAlreadyExistsException If the destination file already exists
@@ -613,13 +614,15 @@ public static Map<String, Stream<?>> excelStreamToObjects(InputStream inputStrea
      * @throws ExtensionNotValidException If the input file extension does not belong to an Excel file
      * @throws IOException If an I/O error has occurred
      */
+    @Deprecated
     public static File excelToCsv(File fileInput) throws FileAlreadyExistsException, OpenWorkbookException, SheetNotFoundException, ExtensionNotValidException, IOException {
         return excelToCsv(fileInput, System.getProperty("java.io.tmpdir"), fileInput.getName().split("\\.")[0].trim(), null);
     }
 
     /**
      * Convert an Excel file into a CSV file<p>
      * The default path is that of the temporary folder. By default, the first sheet is chosen and the filename will be the same as the input file if not specified
+     * @deprecated since version 0.4.0
      * @param fileInput The input Excel file that will be converted into a CSV file
      * @param sheetName The name of the sheet to open
      * @return A CSV file that contains the same lines as the Excel file
@@ -629,13 +632,15 @@ public static File excelToCsv(File fileInput) throws FileAlreadyExistsException,
      * @throws ExtensionNotValidException If the input file extension does not belong to an Excel file
      * @throws IOException If an I/O error has occurred
      */
+    @Deprecated
     public static File excelToCsv(File fileInput, String sheetName) throws FileAlreadyExistsException, OpenWorkbookException, SheetNotFoundException, ExtensionNotValidException, IOException {
         return excelToCsv(fileInput, System.getProperty("java.io.tmpdir"), fileInput.getName().split("\\.")[0].trim(), sheetName);
     }
 
     /**
      * Convert an Excel file into a CSV file<p>
      * By default, the first sheet is chosen
+     * @deprecated since version 0.4.0
      * @param fileInput The input Excel file that will be converted into a CSV file
      * @param path The destination path of the output file
      * @param filename The name of the output file without the extension
@@ -646,12 +651,14 @@ public static File excelToCsv(File fileInput, String sheetName) throws FileAlrea
      * @throws ExtensionNotValidException If the input file extension does not belong to an Excel file
      * @throws IOException If an I/O error has occurred
      */
+    @Deprecated
     public static File excelToCsv(File fileInput, String path, String filename) throws FileAlreadyExistsException, OpenWorkbookException, SheetNotFoundException, ExtensionNotValidException, IOException {
         return excelToCsv(fileInput, path, filename, null);
     }
 
     /**
      * Convert an Excel file into a CSV file
+     * @deprecated since version 0.4.0
      * @param fileInput The input Excel file that will be converted into a CSV file
      * @param path The destination path of the output file
      * @param filename The name of the output file without the extension
@@ -663,6 +670,7 @@ public static File excelToCsv(File fileInput, String path, String filename) thro
      * @throws ExtensionNotValidException If the input file extension does not belong to an Excel file
      * @throws IOException If an I/O error has occurred
      */
+    @Deprecated
     public static File excelToCsv(File fileInput, String path, String filename, String sheetName) throws ExtensionNotValidException, IOException, OpenWorkbookException, SheetNotFoundException, FileAlreadyExistsException {
         /* Open file excel */
         ExcelWorkbook excelWorkbook = ExcelWorkbook.open(fileInput);
@@ -697,6 +705,74 @@ public static File excelToCsv(File fileInput, String path, String filename, Stri
         return csvFile;
     }
 
+    public static Map<String, byte[]> excelToCsvByte(byte[] bytes) throws OpenWorkbookException, IOException {
+        /* Open InputStream */
+        InputStream inputStream = new ByteArrayInputStream(bytes);
+        Map<String, byte[]> byteArrayMap = new HashMap<>();
+
+        Map<String, OutputStream> outputStreamMap = excelToCsvStream(inputStream);
+
+        /* iterate all the outputStream */
+        for (Map.Entry<String, OutputStream> entry : outputStreamMap.entrySet()) {
+            ByteArrayOutputStream baos = (ByteArrayOutputStream) entry.getValue();
+            byteArrayMap.put(entry.getKey(), baos.toByteArray());
+        }
+
+        return byteArrayMap;
+    }
+
+    public static Map<String, File> excelToCsvFile(File excelFile, String path) throws IOException, OpenWorkbookException {
+        /* Open InputStream */
+        FileInputStream fileInputStream = new FileInputStream(excelFile);
+        Map<String, File> fileMap = new HashMap<>();
+
+        Map<String, OutputStream> outputStreamMap = excelToCsvStream(fileInputStream);
+
+        /* iterate all the outputStream */
+        for (Map.Entry<String, OutputStream> entry : outputStreamMap.entrySet()) {
+            String pathname = path + "/" + entry.getKey() + "." + Extension.CSV.getExt();
+            FileOutputStream fileOutputStream = new FileOutputStream(pathname);
+            ByteArrayOutputStream baos = (ByteArrayOutputStream) entry.getValue();
+            fileOutputStream.write(baos.toByteArray());
+            File file = new File(pathname);
+            fileMap.put(entry.getKey(), file);
+            fileOutputStream.close();
+        }
+
+        return fileMap;
+    }
+
+    public static Map<String, OutputStream> excelToCsvStream(InputStream excelStream) throws OpenWorkbookException, IOException {
+        /* Open file excel */
+        ExcelWorkbook excelWorkbook = new ExcelWorkbook(excelStream);
+        List<ExcelSheet> excelSheets = excelWorkbook.getSheets();
+
+        Map<String, OutputStream> map = new HashMap<>();
+
+        /* Iterate all the Sheets */
+        for (ExcelSheet excelSheet : excelSheets) {
+            OutputStream outputStream = new ByteArrayOutputStream();
+            Writer writer = new OutputStreamWriter(outputStream);
+            CSVWriter csvWriter = new CSVWriter(writer);
+
+            DataFormatter formatter = new DataFormatter(true);
+            for (ExcelRow excelRow : excelSheet.getRows()) {
+                List<String> data = new LinkedList<>();
+                for (ExcelCell excelCell : excelRow.getCells()) {
+                    data.add(formatter.formatCellValue(excelCell.getCell()));
+                }
+                csvWriter.writeNext(data.toArray(data.toArray(new String[0])));
+            }
+            csvWriter.close();
+            map.put(excelSheet.getName(), outputStream);
+        }
+
+        /* Close workbook */
+        excelWorkbook.close();
+
+        return map;
+    }
+
     /**
      * Convert a CSV file into an Excel file<p>
      * The default path is that of the temporary folder. By default, the filename will be the same as the input file if not specified and the extension is XLSX

src/test/java/io/github/mbenincasa/javaexcelutils/tools/ConverterTest.java

@@ -605,4 +605,67 @@ void excelStreamToObjects() throws IOException, OpenWorkbookException, SheetNotF
         Assertions.assertEquals(20, people.get(0).getAge());
         fileInputStream.close();
     }
+
+    @Test
+    void excelToCsvByte() throws IOException, OpenWorkbookException, CsvValidationException {
+        byte[] bytes = Files.readAllBytes(excelFile.toPath());
+        Map<String, byte[]> byteMap = Converter.excelToCsvByte(bytes);
+        File csvFile = new File("person.csv");
+        FileOutputStream fileOutputStream = new FileOutputStream(csvFile);
+        fileOutputStream.write(byteMap.get("Person"));
+        FileReader fileReader = new FileReader(csvFile);
+        CSVReader csvReader = new CSVReader(fileReader);
+        String[] values = csvReader.readNext();
+        Assertions.assertEquals("LAST NAME", values[0]);
+        Assertions.assertEquals("NAME", values[1]);
+        Assertions.assertEquals("AGE", values[2]);
+        values = csvReader.readNext();
+        Assertions.assertEquals("Rossi", values[0]);
+        Assertions.assertEquals("Mario", values[1]);
+        Assertions.assertEquals(20, Integer.parseInt(values[2]));
+        fileOutputStream.close();
+        csvReader.close();
+        csvFile.delete();
+    }
+
+    @Test
+    void excelToCsvFile() throws OpenWorkbookException, IOException, CsvValidationException {
+        Map<String, File> fileMap = Converter.excelToCsvFile(excelFile, "./src/");
+        FileReader fileReader = new FileReader(fileMap.get("Person"));
+        CSVReader csvReader = new CSVReader(fileReader);
+        String[] values = csvReader.readNext();
+        Assertions.assertEquals("LAST NAME", values[0]);
+        Assertions.assertEquals("NAME", values[1]);
+        Assertions.assertEquals("AGE", values[2]);
+        values = csvReader.readNext();
+        Assertions.assertEquals("Rossi", values[0]);
+        Assertions.assertEquals("Mario", values[1]);
+        Assertions.assertEquals(20, Integer.parseInt(values[2]));
+        csvReader.close();
+        fileMap.get("Person").delete();
+    }
+
+    @Test
+    void excelToCsvStream() throws IOException, OpenWorkbookException, CsvValidationException {
+        FileInputStream fileInputStream = new FileInputStream(excelFile);
+        Map<String, OutputStream> outputStreamMap = Converter.excelToCsvStream(fileInputStream);
+        FileOutputStream fileOutputStream = new FileOutputStream("person.csv");
+        ByteArrayOutputStream baos = (ByteArrayOutputStream) outputStreamMap.get("Person");
+        fileOutputStream.write(baos.toByteArray());
+        File csvFile = new File("person.csv");
+        FileReader fileReader = new FileReader(csvFile);
+        CSVReader csvReader = new CSVReader(fileReader);
+        String[] values = csvReader.readNext();
+        Assertions.assertEquals("LAST NAME", values[0]);
+        Assertions.assertEquals("NAME", values[1]);
+        Assertions.assertEquals("AGE", values[2]);
+        values = csvReader.readNext();
+        Assertions.assertEquals("Rossi", values[0]);
+        Assertions.assertEquals("Mario", values[1]);
+        Assertions.assertEquals(20, Integer.parseInt(values[2]));
+        fileOutputStream.close();
+        csvReader.close();
+        csvFile.delete();
+        fileInputStream.close();
+    }
 }