java - 无法删除 NetBeans 中 servlet 中目录中的所有文件

Question

我无法删除目录中的所有文件。它是 NetBeans 中的 servlet 应用程序。

 public void updateRootFile(String directorypath, String appID, String[] appName) throws IOException { 
    FileInputStream  finStream =null;
    BufferedReader br = null;
    OutputStreamWriter outStream = null;
    FileInputStream  fins = null;

    String strLine="";       

    try {      
        File[] listOfFiles = fileLists("D:\\root\\");
        for (int i = 0; i < listOfFiles.length; i++) {
            String rootFiles = listOfFiles[i].getName();

            File rootFile = new File("D:/root/"+rootFiles);           
            File copyFile = new File("D:/root1/"+rootFiles);

            finStream = new FileInputStream(rootFile);

            //String propertyStr = "root.label." + appID;
            //properties.load(new InputStreamReader(finStream, Charset.forName("UTF-8")));
            //String getAppName = properties.getProperty("root.label." + appID);
            //String toUtf =new String(appName[i].getBytes("iso-8859-1"), "UTF-8")  ;
            //String oldChar =  propertyStr + "=" + getAppName;
            //String newChar = propertyStr + "=" + toUtf;

            fins = new FileInputStream(rootFile);

            br = new BufferedReader(new InputStreamReader(fins, "UTF-8"));
            outStream = new OutputStreamWriter(new FileOutputStream(copyFile), "UTF-8");
            while ((strLine = br.readLine()) != null) {               
                strLine = strLine.replace("hai", "haai");
                outStream.write(strLine);
                outStream.write("\r\n");
            }
            outStream.flush();
            outStream.close();
            br.close();
            fins.close();
            finStream.close();                
        }                 
    } catch (Exception e) {
        System.out.println("Excpetion : " + e);
    } 

    File rootFileone = new File("D:/root");     
    boolean check= deleteDir(rootFileone);      
}


public static boolean deleteDir(File dir) {
    if (dir.isDirectory()) {
        String[] children = dir.list();
        for (int i=1; i<children.length; i++) {
            boolean success = deleteDir(new File(dir, children[i]));
            //if (!success) {
             //   return false;
           // }
        }
    }
    // The directory is now empty so delete it
    return dir.delete();
}


private  File[] fileLists(String directorypath) {
    folder = new File(directorypath);
    listOfFiles = folder.listFiles();
    return listOfFiles;
}

我的文件夹中有 29 个 .properties 文件。但在此循环中，始终至少有一个文件保持未删除状态。因此我无法删除该文件夹。

Answer 1

如果文件已被其他程序打开，则无法删除该文件。

造成这种情况的可能原因有很多，无论是在您自己的代码内部还是外部。我假设您只在自己的代码中管理这些文件。您需要确保在 InputStream/OutputStream 或 Reader/上调用 close() 方法Writer 位于您正在读取/写入文件的 try block 的 finally block 中。

因此，请确保遵循以下 Java IO 习惯用法:创建、使用和关闭 InputStream/OutputStream 和 Reader/作家资源。

Writer writer = null;

try {
    writer = new FileWriter(file); // Just an example. Can be any Writer.
    writer.write(something);
    // ...
} finally {
    if (writer != null) try { writer.close(); } catch (IOException ignore) {}
}

或者当您已经使用 Java 7 时:

try (Writer writer = new FileWriter(file)) {
    writer.write(something);
    // ...
}

当 try block 离开时，它将自动关闭 AutoCloseable 资源。