如何正确关闭zipinputstream,以便在操作结束时以编程方式关闭zip文件?

kokeuurv  于 2021-07-09  发布在  Java
关注(0)|答案(1)|浏览(427)

作为我的项目自动更新功能的一部分,我的程序从web服务器下载一个zip文件,然后在重新启动应用程序之前将其解压到位(下面是代码逻辑)。zip文件应该在文件更新之后和主应用程序启动之前被删除。
下载和文件更新工作正常,但我面临的问题是,线 Files.delete(file.toPath()); 引发类型错误 java.nio.file.FileSystemException 有描述吗 The process cannot access the file because it is being used by another process . 似乎是 zis.close() 没有有效地释放 update.zip . 有什么迹象表明我能解决这个问题吗?

public static void main(String[] args) {

    String updateFileName = "update.zip";
    boolean updateSuccess=true;
    File file = new File(updateFileName);
    if (file.exists()) {
        String dir = file.getAbsolutePath();
        dir = dir.substring(0, dir.length() - 10);
        try {
            update(updateFileName, dir);
        }
        catch (Exception e) {
            updateSuccess = false;
            System.err.print("update failed !");
            e.printStackTrace();
        }
        if (updateSuccess) {
            try {
                System.err.print("Trying to delete  " + file.getAbsolutePath());
                Files.delete(Path.of(file.getAbsolutePath()));
            } catch (IOException e) {
                System.err.print("zip file could not be deleted after update !: " + e );
            }
        }
    }
    HO.main(args);
}

private static void update(String zipFile, String _destDir) throws IOException {
    int len;
    Pattern pattern;
    String fileName;
    byte[] buffer = new byte[1024];
    File destDir = new File(_destDir);
    try (ZipInputStream zis = new ZipInputStream(new FileInputStream(zipFile))) {
        ZipEntry zipEntry = zis.getNextEntry();
        while (zipEntry != null) {
            File destFile = new File(destDir, fileName);
            File parentDirectory = destFile.getParentFile();
            if (!parentDirectory.exists()) parentDirectory.mkdirs();
            else {
                if (destFile.exists()) destFile.delete();
            }
            FileOutputStream fos = new FileOutputStream(destFile, false);
            while ((len = zis.read(buffer)) > 0) {
                fos.write(buffer, 0, len);
            }
            fos.close();
            zipEntry = zis.getNextEntry();
        }
        zis.closeEntry();
    }
}
hof1towb

hof1towb1#

如果流实现了closable,则应该对其使用“try with resource”。。检查下面https://docs.oracle.com/javase/tutorial/essential/exceptions/tryresourceclose.html

if (file.exists()) {
            try (ZipInputStream zis = new ZipInputStream(new FileInputStream(updateFileName))) {
                zis.closeEntry();
            }
            Files.delete(Path.of(file.getAbsolutePath()));
            myApp.main(args);
        }

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