android系统中重命名文件扩展名 [英] renaming file extensions in android

问题描述

我能够改变文件扩展名，例如，从.MP4到.xmp4但不是改扩建，我只是想添加一个。例如文件名之前 mikey.jpg 到 .mikey.jpg 。我该怎么做呢？

I am able to change file extensions, for example, from ".mp4" to ".xmp4" but instead of changing extension, i simply want to add a "." before a file name for example "mikey.jpg" to ".mikey.jpg". how do i do that?

public static final String[] TARGET_EXTENSIONS = { "mp4", "mp3", "mp55", "other" };

public void walkdir(File dir) {
    File listFile[] = dir.listFiles();
    if (listFile != null) {
        for (int i = 0; i < listFile.length; i++) {
            if (listFile[i].isDirectory()) {
                walkdir(listFile[i]);
            } else {
                String fPath = listFile[i].getPath();

                for (String ext : TARGET_EXTENSIONS) {
                    fPath = fPath.replace("." + ext, ".x" + ext);
                }

                listFile[i].renameTo(new File(fPath));
            }
        }
    }
}

下面是完整的code

here is the full code

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    view = (LinearLayout) findViewById(R.id.view);

    // getting SDcard root path
    File dir = new File(Environment.getExternalStorageDirectory()
            .getAbsolutePath());
    walkdir(dir);
}

public static final String[] TARGET_EXTENSIONS = { "mp4", "mp3", "avi", "other" };

public void walkdir(File dir) {
    File listFile[] = dir.listFiles();
    if (listFile != null) {
        for (int i = 0; i < listFile.length; i++) {
            if (listFile[i].isDirectory()) {
                walkdir(listFile[i]);
            } else {
                String fPath = listFile[i].getPath();

                for (String ext : TARGET_EXTENSIONS) {
                    fPath = fPath.replace("." + ext, ".x" + ext);
                }

                listFile[i].renameTo(new File(fPath));
            }
        }
    }
}

}

推荐答案

首先，你做的字符串文件名=的文件列表[I] .getName（）; ，这应该给你名字，然后你做字符串FULLPATH =的文件列表[I] .getAbsolutePath（）; 来获得完整的路径，然后你做 INT indexOfFileNameStart = FULLPATH .lastIndexOf（文件名），那么你从完整得到一个字符串生成器实例，像这样 StringBuilder的SB =新的StringBuilder（完整路径）; ，现在给你打电话某人 sb.insert insert方法（indexOfFileNameStart，。），现在某人应该有你想要的字符串，只需将其构建为字符串 SB的ToString（）

first you do String fileName = listFile[i].getName(); , which should give you the name, next you do String fullPath = listFile[i].getAbsolutePath(); to get the full path, then you do int indexOfFileNameStart = fullPath.lastIndexOf(fileName) , then you get a string builder instance from fullPath like so StringBuilder sb = new StringBuilder(fullPath); , now you call the insert method on sb sb.insert(indexOfFileNameStart, "."), now sb should have the string you desire, just construct it to string sb.toString()

在伊利诺伊州code添加此

Ill add this in code

private String putDotBeforeFileName(File file) {
    String fileName = file.getName();
    String fullPath = file.getAbsolutePath();
    int indexOfFileNameStart = fullPath.lastIndexOf(fileName);
    StringBuilder sb = new StringBuilder(fullPath);
    sb.insert(indexOfFileNameStart, ".");
    String myRequiredFileName = sb.toString();
    file.renameTo(new File(myRequiredFileName));
    return myRequiredFileName;
}

修改

这是你如何可以在code使用上面的方法

This is how you can use the above method in your code

public void walkdir(File dir) {
    File listFile[] = dir.listFiles();
    if (listFile != null) {
        for (int i = 0; i < listFile.length; i++) {
            if (listFile[i].isDirectory()) {
                walkdir(listFile[i]);
            } else {
                String fPath = listFile[i].getPath();
                for (String ext : TARGET_EXTENSIONS) {
                    if(fPath.endsWith(ext)) {
                        putDotBeforeFileName(listFile[i]);
                    }
                }
            }
        }
    }
}

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