如何在Java中向现有zip文件添加条目？ [英] How can I add entries to an existing zip file in Java?

问题描述

可能重复：

使用Java将文件附加到zip文件

使用ZipOutputStream打开文件会覆盖它。有没有办法保留文件并只添加新条目？

Opening the file with a ZipOutputStream overwrites it. Is there a way to keep the file and just add new entries?

推荐答案

该函数将现有的zip文件重命名为临时文件然后添加现有zip中的所有条目以及新文件，不包括与其中一个新文件同名的zip条目。

The function renames the existing zip file to a temporary file and then adds all entries in the existing zip along with the new files, excluding the zip entries that have the same name as one of the new files.

public static void addFilesToExistingZip(File zipFile,
         File[] files) throws IOException {
        // get a temp file
    File tempFile = File.createTempFile(zipFile.getName(), null);
        // delete it, otherwise you cannot rename your existing zip to it.
    tempFile.delete();

    boolean renameOk=zipFile.renameTo(tempFile);
    if (!renameOk)
    {
        throw new RuntimeException("could not rename the file "+zipFile.getAbsolutePath()+" to "+tempFile.getAbsolutePath());
    }
    byte[] buf = new byte[1024];

    ZipInputStream zin = new ZipInputStream(new FileInputStream(tempFile));
    ZipOutputStream out = new ZipOutputStream(new FileOutputStream(zipFile));

    ZipEntry entry = zin.getNextEntry();
    while (entry != null) {
        String name = entry.getName();
        boolean notInFiles = true;
        for (File f : files) {
            if (f.getName().equals(name)) {
                notInFiles = false;
                break;
            }
        }
        if (notInFiles) {
            // Add ZIP entry to output stream.
            out.putNextEntry(new ZipEntry(name));
            // Transfer bytes from the ZIP file to the output file
            int len;
            while ((len = zin.read(buf)) > 0) {
                out.write(buf, 0, len);
            }
        }
        entry = zin.getNextEntry();
    }
    // Close the streams        
    zin.close();
    // Compress the files
    for (int i = 0; i < files.length; i++) {
        InputStream in = new FileInputStream(files[i]);
        // Add ZIP entry to output stream.
        out.putNextEntry(new ZipEntry(files[i].getName()));
        // Transfer bytes from the file to the ZIP file
        int len;
        while ((len = in.read(buf)) > 0) {
            out.write(buf, 0, len);
        }
        // Complete the entry
        out.closeEntry();
        in.close();
    }
    // Complete the ZIP file
    out.close();
    tempFile.delete();
}

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