How to programmatically move, copy and delete file

2019-01-02 19:39发布

I want to programmatically move, copy and delete files and directories on SD card. I've done a Google search but couldn't find anything useful.

13条回答
千与千寻千般痛.
2楼-- · 2019-01-02 20:34

set the correct permissions in the manifest

     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

below is a function that will programmatically move your file

private void moveFile(String inputPath, String inputFile, String outputPath) {

    InputStream in = null;
    OutputStream out = null;
    try {

        //create output directory if it doesn't exist
        File dir = new File (outputPath); 
        if (!dir.exists())
        {
            dir.mkdirs();
        }


        in = new FileInputStream(inputPath + inputFile);        
        out = new FileOutputStream(outputPath + inputFile);

        byte[] buffer = new byte[1024];
        int read;
        while ((read = in.read(buffer)) != -1) {
            out.write(buffer, 0, read);
        }
        in.close();
        in = null;

            // write the output file
            out.flush();
        out.close();
        out = null;

        // delete the original file
        new File(inputPath + inputFile).delete();  


    } 

         catch (FileNotFoundException fnfe1) {
        Log.e("tag", fnfe1.getMessage());
    }
          catch (Exception e) {
        Log.e("tag", e.getMessage());
    }

}

To Delete the file use

private void deleteFile(String inputPath, String inputFile) {
    try {
        // delete the original file
        new File(inputPath + inputFile).delete();  
    }
    catch (Exception e) {
        Log.e("tag", e.getMessage());
    }
}

To copy

private void copyFile(String inputPath, String inputFile, String outputPath) {

    InputStream in = null;
    OutputStream out = null;
    try {

        //create output directory if it doesn't exist
        File dir = new File (outputPath); 
        if (!dir.exists())
        {
            dir.mkdirs();
        }


        in = new FileInputStream(inputPath + inputFile);        
        out = new FileOutputStream(outputPath + inputFile);

        byte[] buffer = new byte[1024];
        int read;
        while ((read = in.read(buffer)) != -1) {
            out.write(buffer, 0, read);
        }
        in.close();
        in = null;

            // write the output file (You have now copied the file)
            out.flush();
        out.close();
        out = null;        

    }  catch (FileNotFoundException fnfe1) {
        Log.e("tag", fnfe1.getMessage());
    }
            catch (Exception e) {
        Log.e("tag", e.getMessage());
    }

}
查看更多
谁念西风独自凉
3楼-- · 2019-01-02 20:36

Move file:

File from = new File(Environment.getExternalStorageDirectory().getAbsolutePath()+"/kaic1/imagem.jpg");
File to = new File(Environment.getExternalStorageDirectory().getAbsolutePath()+"/kaic2/imagem.jpg");
from.renameTo(to);
查看更多
素衣白纱
4楼-- · 2019-01-02 20:38
File from = new File(Environment.getExternalStorageDirectory().getAbsolutePath().getAbsolutePath()+"/kaic1/imagem.jpg");
File to = new File(Environment.getExternalStorageDirectory().getAbsolutePath()+"/kaic2/imagem.jpg");
from.renameTo(to);
查看更多
无色无味的生活
5楼-- · 2019-01-02 20:41

If you are using Guava, you can use Files.move(source, dest)

查看更多
与君花间醉酒
6楼-- · 2019-01-02 20:42

Delete

public static void deleteRecursive(File fileOrDirectory) {

 if (fileOrDirectory.isDirectory())
    for (File child : fileOrDirectory.listFiles())
        deleteRecursive(child);

    fileOrDirectory.delete();

    }

check this link for above function.

Copy

public static void copyDirectoryOneLocationToAnotherLocation(File sourceLocation, File targetLocation)
    throws IOException {

if (sourceLocation.isDirectory()) {
    if (!targetLocation.exists()) {
        targetLocation.mkdir();
    }

    String[] children = sourceLocation.list();
    for (int i = 0; i < sourceLocation.listFiles().length; i++) {

        copyDirectoryOneLocationToAnotherLocation(new File(sourceLocation, children[i]),
                new File(targetLocation, children[i]));
    }
} else {

    InputStream in = new FileInputStream(sourceLocation);

    OutputStream out = new FileOutputStream(targetLocation);

    // Copy the bits from instream to outstream
    byte[] buf = new byte[1024];
    int len;
    while ((len = in.read(buf)) > 0) {
        out.write(buf, 0, len);
    }
    in.close();
    out.close();
}

}

Move

move is nothing just copy the folder one location to another then delete the folder thats it

manifest

     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
查看更多
余欢
7楼-- · 2019-01-02 20:42
/**
     * Copy the local DB file of an application to the root of external storage directory
     * @param context the Context of application
     * @param dbName The name of the DB
     */
    private void copyDbToExternalStorage(Context context , String dbName){

        try {
            File name = context.getDatabasePath(dbName);
            File sdcardFile = new File(Environment.getExternalStorageDirectory() , "test.db");//The name of output file
            sdcardFile.createNewFile();
            InputStream inputStream = null;
            OutputStream outputStream = null;
            inputStream = new FileInputStream(name);
            outputStream = new FileOutputStream(sdcardFile);
            byte[] buffer = new byte[1024];
            int read;
            while ((read = inputStream.read(buffer)) != -1) {
                outputStream.write(buffer, 0, read);
            }
            inputStream.close();
            outputStream.flush();
            outputStream.close();
        }
        catch (Exception e) {
            Log.e("Exception" , e.toString());
        }
    }
查看更多
登录 后发表回答