如何使用Java创建可追加的Excel表格

Question

我希望创建一个可追加的Excel表格，其中有四列：stream1、stream2、stream3和stream4。

第一次插入数据时，我只想要填充第一列（stream1），之后逐个填充其他列。

这是我正在使用的代码：

 public void createFile(Jqueue stream1, Jqueue stream2, Jqueue stream3, Jqueue stream4) {
    try {

        String filename = "path";
        boolean alreadyExists = (new File(filename)).exists();

        HSSFRow rowhead = sheet1.createRow((short) 0);
        rowhead.createCell((short) 0).setCellValue("Stream 1");
        rowhead.createCell((short) 1).setCellValue("Stream 2");
        rowhead.createCell((short) 2).setCellValue("Stream 3");
        rowhead.createCell((short) 3).setCellValue("Stream 4");


        int i = 1;
        while (!stream1.isEmpty()) {
            String urlstream1 = "";
            String urlstream2 = "";
            String urlstream3 = "";
            String urlstream4 = "";
            HSSFRow row = sheet1.createRow((short) i);
            try {
                if (stream1.size() > 0) {
                    urlstream1 = stream1.dequeue().toString();
                }
            } catch (Exception ex) {
            }
            try {
                if (stream2.size() > 0) {
                    urlstream2 = stream2.dequeue().toString();
                }
            } catch (Exception ex) {
            }
            try {
                if (stream3.size() > 0) {
                    urlstream3 = stream3.dequeue().toString();
                }
            } catch (Exception ex) {
            }
            try {
                if (stream4.size() > 0) {
                    urlstream4 = stream4.dequeue().toString();
                }
            } catch (Exception ex) {
            }
            row.createCell((short) 0).setCellValue(urlstream1);
            row.createCell((short) 1).setCellValue(urlstream2);
            row.createCell((short) 2).setCellValue(urlstream3);
            row.createCell((short) 3).setCellValue(urlstream4);
            i++;
        }

        FileOutputStream fileOut = new FileOutputStream(filename);
        hwb.write(fileOut);
        fileOut.close();

但这不是可附加的代码。它逐行插入数据。

提前感谢。

- narendra

Answer 1

我想你只需要稍微改动一下代码就可以了。

尝试将以下代码：

int i = 1;

替换为：

int i = sheet1.getLastRowNum() + 1;

你还需要稍微修改一下读写文件的实现方式。

- Abhishek