使用Java和Jexcelapi从Excel编写多个CSV文件

我正在尝试创建一个程序，将excel中的所有数据写入多个csv文件

目前，我的程序创建了n个文件，并且在最后一个csv文件上只写入了excel的最后一行

编程背景观察： 似乎文件正在写入。但对于每一个写入的行，它会以某种方式创建相同的文件250次。它将删除最后写入的行

使用输出流或缓冲写入程序时可能会遇到一些问题。我就是搞不懂那是什么

writeRow（）方法：

public static void writeRow(BufferedWriter bw, Cell[] row) throws IOException { 
    if (row.length > 0) {
        bw.write(row[0].getContents());
        for (int j = 1; j < row.length; j++) {
            bw.write(',');
            bw.write(row[j].getContents());
        }
    }
}

Exception in thread "main" java.io.IOException: Stream closed
at sun.nio.cs.StreamEncoder.ensureOpen(Unknown Source)
at sun.nio.cs.StreamEncoder.write(Unknown Source)
at java.io.OutputStreamWriter.write(Unknown Source)
at java.io.BufferedWriter.flushBuffer(Unknown Source)
at java.io.BufferedWriter.flush(Unknown Source)
at Main.main(Main.java:46)

以下是例外情况。

public static void writeRow(BufferedWriter bw, Cell[] row) throws IOException { 
    if (row.length > 0) {
        bw.write(row[0].getContents());
        for (int j = 1; j < row.length; j++) {
            bw.write(',');
            bw.write(row[j].getContents());
        }
    }
}

Exception in thread "main" java.io.IOException: Stream closed
at sun.nio.cs.StreamEncoder.ensureOpen(Unknown Source)
at sun.nio.cs.StreamEncoder.write(Unknown Source)
at java.io.OutputStreamWriter.write(Unknown Source)
at java.io.BufferedWriter.flushBuffer(Unknown Source)
at java.io.BufferedWriter.flush(Unknown Source)
at Main.main(Main.java:46)

下面是代码的一些链接

我做错了什么

这是svn主干：

-

• 就像上面的那个

---

重要建议： 不要在同一个缓冲区中写入，而是在每n个记录之后停止行。然后，读一读 请重新打开工作表。然后，在另一个文件上输出缓冲区。在同一缓冲区上写入时，无法更改文件
下面是一个个完整的解决方案：
静态变量：

public static BufferedWriter setFile (int i) throws IOException {
    i=i/250;
    File f = new File(dir + "file-" + (i+1) + ".csv");
    // If i has changed, create a new file. Else, append to current file.
    String encoding = "UTF8";
    OutputStream os = null;
    OutputStreamWriter osw = null;
    BufferedWriter bw = null;
    Boolean append = null;
    try {
        // If i has changed, create a new file, else append.
        if (i%250==0) {
            append = new Boolean("TRUE");
            os = new FileOutputStream(f,append);
        } else {
            append = new Boolean("FALSE");
            os = new FileOutputStream(f, append);
        }
        osw = new OutputStreamWriter(os, encoding);
        bw = new BufferedWriter(osw);

    } finally {
        os.close();
        osw.close();
    }
    return bw;
}

public static int maxRecords = 250;
public static String directory = "C:\\Users\\User02\\workspace\\ExcelToCsv\\src\\";
public static String inputFile = directory + "inventory.xls";

public static void main(String[] args) throws BiffException, IOException {
Sheet s = getSheet();
    int countRows = s.getRows(); // counts the number of rows in the sheet.
    int numberOfFiles = (countRows/maxRecords)+1;

    for(int file=0; file<numberOfFiles; file++) {
        System.out.println("Create file number " + (file+1));
        int fileNumber = file+1;
        System.out.println("Start number: " + ((file*maxRecords)+1));
        int startNumber = (file*maxRecords);
        populateFile(fileNumber,startNumber);
        System.out.println("");
    }
}

public static void populateFile(int fileNumber, int startNumber) 
    throws IOException, BiffException {
        BufferedWriter bw = setFile(fileNumber);
        Sheet s = getSheet();
        Cell[] row = null;
        writeRow(bw,s.getRow(0));
        bw.newLine(); 
        int limit = getLimit(s,startNumber);
        System.out.println("End Number:" + limit);
        System.out.println();
        for (int i = startNumber; i < limit ; i++) {
            row = s.getRow(i); 
            //System.out.println(i);
            writeRow(bw,row);
            bw.newLine();
        }
        bw.flush();
        bw.close();
    }

public static Sheet getSheet() throws BiffException, IOException {
    WorkbookSettings ws = new WorkbookSettings();
    ws.setLocale(new Locale("en", "EN"));
    Workbook w = Workbook.getWorkbook(new File(inputFile),ws);
    Sheet s = w.getSheet(0);
    return s;
}

public static BufferedWriter setFile(int fileNumber) throws IOException {
    String csvFilename = directory + "file-"+ fileNumber +".csv";
    FileWriter csvFile = new FileWriter(csvFilename);
    BufferedWriter bw = new BufferedWriter(csvFile);
    return bw;
}

public static int getLimit(Sheet s, int startNumber) {
    int limit;
    int countRows = s.getRows();
    if (startNumber+maxRecords<=countRows) {
        limit = startNumber + maxRecords;
    } else {
        limit = startNumber + (countRows-startNumber);
    }
    return limit;
}

public static void writeRow(BufferedWriter bw, Cell[] row) throws IOException { 
    if (row.length > 0) {
        bw.write(row[0].getContents());
        for (int j = 1; j < row.length; j++) {
            bw.write(',');
            bw.write(row[j].getContents());
        }
    }
}

Main:

public static BufferedWriter setFile (int i) throws IOException {
    i=i/250;
    File f = new File(dir + "file-" + (i+1) + ".csv");
    // If i has changed, create a new file. Else, append to current file.
    String encoding = "UTF8";
    OutputStream os = null;
    OutputStreamWriter osw = null;
    BufferedWriter bw = null;
    Boolean append = null;
    try {
        // If i has changed, create a new file, else append.
        if (i%250==0) {
            append = new Boolean("TRUE");
            os = new FileOutputStream(f,append);
        } else {
            append = new Boolean("FALSE");
            os = new FileOutputStream(f, append);
        }
        osw = new OutputStreamWriter(os, encoding);
        bw = new BufferedWriter(osw);

    } finally {
        os.close();
        osw.close();
    }
    return bw;
}

public static int maxRecords = 250;
public static String directory = "C:\\Users\\User02\\workspace\\ExcelToCsv\\src\\";
public static String inputFile = directory + "inventory.xls";

public static void main(String[] args) throws BiffException, IOException {
Sheet s = getSheet();
    int countRows = s.getRows(); // counts the number of rows in the sheet.
    int numberOfFiles = (countRows/maxRecords)+1;

    for(int file=0; file<numberOfFiles; file++) {
        System.out.println("Create file number " + (file+1));
        int fileNumber = file+1;
        System.out.println("Start number: " + ((file*maxRecords)+1));
        int startNumber = (file*maxRecords);
        populateFile(fileNumber,startNumber);
        System.out.println("");
    }
}

public static void populateFile(int fileNumber, int startNumber) 
    throws IOException, BiffException {
        BufferedWriter bw = setFile(fileNumber);
        Sheet s = getSheet();
        Cell[] row = null;
        writeRow(bw,s.getRow(0));
        bw.newLine(); 
        int limit = getLimit(s,startNumber);
        System.out.println("End Number:" + limit);
        System.out.println();
        for (int i = startNumber; i < limit ; i++) {
            row = s.getRow(i); 
            //System.out.println(i);
            writeRow(bw,row);
            bw.newLine();
        }
        bw.flush();
        bw.close();
    }

public static Sheet getSheet() throws BiffException, IOException {
    WorkbookSettings ws = new WorkbookSettings();
    ws.setLocale(new Locale("en", "EN"));
    Workbook w = Workbook.getWorkbook(new File(inputFile),ws);
    Sheet s = w.getSheet(0);
    return s;
}

public static BufferedWriter setFile(int fileNumber) throws IOException {
    String csvFilename = directory + "file-"+ fileNumber +".csv";
    FileWriter csvFile = new FileWriter(csvFilename);
    BufferedWriter bw = new BufferedWriter(csvFile);
    return bw;
}

public static int getLimit(Sheet s, int startNumber) {
    int limit;
    int countRows = s.getRows();
    if (startNumber+maxRecords<=countRows) {
        limit = startNumber + maxRecords;
    } else {
        limit = startNumber + (countRows-startNumber);
    }
    return limit;
}

public static void writeRow(BufferedWriter bw, Cell[] row) throws IOException { 
    if (row.length > 0) {
        bw.write(row[0].getContents());
        for (int j = 1; j < row.length; j++) {
            bw.write(',');
            bw.write(row[j].getContents());
        }
    }
}

设置要写入的文件：

public static BufferedWriter setFile (int i) throws IOException {
    i=i/250;
    File f = new File(dir + "file-" + (i+1) + ".csv");
    // If i has changed, create a new file. Else, append to current file.
    String encoding = "UTF8";
    OutputStream os = null;
    OutputStreamWriter osw = null;
    BufferedWriter bw = null;
    Boolean append = null;
    try {
        // If i has changed, create a new file, else append.
        if (i%250==0) {
            append = new Boolean("TRUE");
            os = new FileOutputStream(f,append);
        } else {
            append = new Boolean("FALSE");
            os = new FileOutputStream(f, append);
        }
        osw = new OutputStreamWriter(os, encoding);
        bw = new BufferedWriter(osw);

    } finally {
        os.close();
        osw.close();
    }
    return bw;
}

public static int maxRecords = 250;
public static String directory = "C:\\Users\\User02\\workspace\\ExcelToCsv\\src\\";
public static String inputFile = directory + "inventory.xls";

public static void main(String[] args) throws BiffException, IOException {
Sheet s = getSheet();
    int countRows = s.getRows(); // counts the number of rows in the sheet.
    int numberOfFiles = (countRows/maxRecords)+1;

    for(int file=0; file<numberOfFiles; file++) {
        System.out.println("Create file number " + (file+1));
        int fileNumber = file+1;
        System.out.println("Start number: " + ((file*maxRecords)+1));
        int startNumber = (file*maxRecords);
        populateFile(fileNumber,startNumber);
        System.out.println("");
    }
}

public static void populateFile(int fileNumber, int startNumber) 
    throws IOException, BiffException {
        BufferedWriter bw = setFile(fileNumber);
        Sheet s = getSheet();
        Cell[] row = null;
        writeRow(bw,s.getRow(0));
        bw.newLine(); 
        int limit = getLimit(s,startNumber);
        System.out.println("End Number:" + limit);
        System.out.println();
        for (int i = startNumber; i < limit ; i++) {
            row = s.getRow(i); 
            //System.out.println(i);
            writeRow(bw,row);
            bw.newLine();
        }
        bw.flush();
        bw.close();
    }

public static Sheet getSheet() throws BiffException, IOException {
    WorkbookSettings ws = new WorkbookSettings();
    ws.setLocale(new Locale("en", "EN"));
    Workbook w = Workbook.getWorkbook(new File(inputFile),ws);
    Sheet s = w.getSheet(0);
    return s;
}

public static BufferedWriter setFile(int fileNumber) throws IOException {
    String csvFilename = directory + "file-"+ fileNumber +".csv";
    FileWriter csvFile = new FileWriter(csvFilename);
    BufferedWriter bw = new BufferedWriter(csvFile);
    return bw;
}

public static int getLimit(Sheet s, int startNumber) {
    int limit;
    int countRows = s.getRows();
    if (startNumber+maxRecords<=countRows) {
        limit = startNumber + maxRecords;
    } else {
        limit = startNumber + (countRows-startNumber);
    }
    return limit;
}

public static void writeRow(BufferedWriter bw, Cell[] row) throws IOException { 
    if (row.length > 0) {
        bw.write(row[0].getContents());
        for (int j = 1; j < row.length; j++) {
            bw.write(',');
            bw.write(row[j].getContents());
        }
    }
}

获取限制：

public static BufferedWriter setFile (int i) throws IOException {
    i=i/250;
    File f = new File(dir + "file-" + (i+1) + ".csv");
    // If i has changed, create a new file. Else, append to current file.
    String encoding = "UTF8";
    OutputStream os = null;
    OutputStreamWriter osw = null;
    BufferedWriter bw = null;
    Boolean append = null;
    try {
        // If i has changed, create a new file, else append.
        if (i%250==0) {
            append = new Boolean("TRUE");
            os = new FileOutputStream(f,append);
        } else {
            append = new Boolean("FALSE");
            os = new FileOutputStream(f, append);
        }
        osw = new OutputStreamWriter(os, encoding);
        bw = new BufferedWriter(osw);

    } finally {
        os.close();
        osw.close();
    }
    return bw;
}

public static int maxRecords = 250;
public static String directory = "C:\\Users\\User02\\workspace\\ExcelToCsv\\src\\";
public static String inputFile = directory + "inventory.xls";

public static void main(String[] args) throws BiffException, IOException {
Sheet s = getSheet();
    int countRows = s.getRows(); // counts the number of rows in the sheet.
    int numberOfFiles = (countRows/maxRecords)+1;

    for(int file=0; file<numberOfFiles; file++) {
        System.out.println("Create file number " + (file+1));
        int fileNumber = file+1;
        System.out.println("Start number: " + ((file*maxRecords)+1));
        int startNumber = (file*maxRecords);
        populateFile(fileNumber,startNumber);
        System.out.println("");
    }
}

public static void populateFile(int fileNumber, int startNumber) 
    throws IOException, BiffException {
        BufferedWriter bw = setFile(fileNumber);
        Sheet s = getSheet();
        Cell[] row = null;
        writeRow(bw,s.getRow(0));
        bw.newLine(); 
        int limit = getLimit(s,startNumber);
        System.out.println("End Number:" + limit);
        System.out.println();
        for (int i = startNumber; i < limit ; i++) {
            row = s.getRow(i); 
            //System.out.println(i);
            writeRow(bw,row);
            bw.newLine();
        }
        bw.flush();
        bw.close();
    }

public static Sheet getSheet() throws BiffException, IOException {
    WorkbookSettings ws = new WorkbookSettings();
    ws.setLocale(new Locale("en", "EN"));
    Workbook w = Workbook.getWorkbook(new File(inputFile),ws);
    Sheet s = w.getSheet(0);
    return s;
}

public static BufferedWriter setFile(int fileNumber) throws IOException {
    String csvFilename = directory + "file-"+ fileNumber +".csv";
    FileWriter csvFile = new FileWriter(csvFilename);
    BufferedWriter bw = new BufferedWriter(csvFile);
    return bw;
}

public static int getLimit(Sheet s, int startNumber) {
    int limit;
    int countRows = s.getRows();
    if (startNumber+maxRecords<=countRows) {
        limit = startNumber + maxRecords;
    } else {
        limit = startNumber + (countRows-startNumber);
    }
    return limit;
}

public static void writeRow(BufferedWriter bw, Cell[] row) throws IOException { 
    if (row.length > 0) {
        bw.write(row[0].getContents());
        for (int j = 1; j < row.length; j++) {
            bw.write(',');
            bw.write(row[j].getContents());
        }
    }
}

public static int getLimit（表s，int startNumber）{
整数极限；
int countRows=s.getRows（）；
if（开始编号+最大记录0）{
write（行[0].getContents（））；
对于（int j=1；j

尝试将功能划分为小类和小单元测试。是的，我已经尝试过了。不知怎的，它缩小了范围来改变我的setFile方法。根据java FileOutputStream，有一个用于附加文件的构造函数。我用了那个构造器。它似乎不起作用。这是否意味着我不需要在setFile方法中创建新的FileOutputStream，而只需要使用当前的方法？关于OutputStream，我还需要了解更多的解释吗？让流保持开放状态不是一个好主意。关闭操作系统流可能无法解决您的问题，但这是一个避免未来麻烦的好主意。谢谢。我马上换。