Android 建立文件夹、生成文件并写入文本文件内容

一、首先添加权限

 
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
二、建立文件夹、生成文件并写入文本文件内容代码
 
private void initData() {
    String filePath = "/sdcard/Test/";
    String fileName = "log.txt";
    
    writeTxtToFile("txt content", filePath, fileName);
}
 
// 将字符串写入到文本文件中
public void writeTxtToFile(String strcontent, String filePath, String fileName) {
    //生成文件夹之后，再生成文件，不然会出错
    makeFilePath(filePath, fileName);
    
    String strFilePath = filePath+fileName;
    // 每次写入时，都换行写
    String strContent = strcontent + "\r\n";
    try {
        File file = new File(strFilePath);
        if (!file.exists()) {
            Log.d("TestFile", "Create the file:" + strFilePath);
            file.getParentFile().mkdirs();
            file.createNewFile();
        }
        RandomAccessFile raf = new RandomAccessFile(file, "rwd");
        raf.seek(file.length());
        raf.write(strContent.getBytes());
        raf.close();
    } catch (Exception e) {
        Log.e("TestFile", "Error on write File:" + e);
    }
}
 
// 生成文件
public File makeFilePath(String filePath, String fileName) {
    File file = null;
    makeRootDirectory(filePath);
    try {
        file = new File(filePath + fileName);
        if (!file.exists()) {
            file.createNewFile();
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
    return file;
}
 
// 生成文件夹
public static void makeRootDirectory(String filePath) {
    File file = null;
    try {
        file = new File(filePath);
        if (!file.exists()) {
            file.mkdir();
        }
    } catch (Exception e) {
        Log.i("error:", e+"");
    }