使用Java和Jexcelapi从Excel编写多个CSV文件

Question

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，并且只在最后一个csv文件中写入了最后一行excel。

编程背景观察：

好像文件正在写。但是对于每个写入的行，它以某种方式创建相同的文件250次。它会删除最后写入的行。

使用 OutputStream 或 BufferedWriter 时，我可能会遇到一些问题。我只是想不通它是什么。

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());
        }
    }
}

setFile（）方法：

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;
}

以下是例外情况。

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)

以下是代码的一些链接。

我做错了什么？

这是svn trunk：

https://franz-opensource.googlecode.com/svn/trunk/ExcelToCsv -

• Click here for the Java Main code就像上面那样。
• Click here to download the sample excel file
• Click here for the jexcelapi download

Answer 1

重要建议： 在每个 nth 记录之后停止行，而不是写在同一个缓冲区上。然后，阅读 工作表再次。然后，在另一个文件上输出缓冲区。在同一缓冲区上写入时，您无法更改文件。

以下是整个解决方案：

静态变量：

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

主要

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("");
    }
}

填充列表：

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();
    }

获取工作表：

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;
}

设置要写入的文件：

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;
}

获得限制：

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;
}

将行写入文件：

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());
        }
    }
}