Android:将文件从一个目录复制到另一个目录

Question

我正在使用以下代码并使用apache commons库将一个文件(临时音频文件)从源文件夹复制到目标文件夹TT_1A.

码:

button1_save.setOnClickListener(new OnClickListener() 
    {
        public void onClick(View v) 
        {
            String sourcePath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/TT/tt_temp.3gp";
            File source = new File(sourcePath);

            String descPath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/TT/tt_1A.3gp";
            File desc = new File(descPath);
            try 
            {
                FileUtils.copyDirectory(source, desc);
            } 
            catch (IOException e) 
            {
                e.printStackTrace();
            }
        }
    }); 

Apache Commons:

http://commons.apache.org/proper/commons-io/download_io.cgi

题:

我已经使用了这个FileUtils函数来复制临时文件并粘贴到desc文件夹作为TT_1A.然而,logcat报告错误,具体如下:

10-17 00:41:04.260: E/AndroidRuntime(27450): FATAL EXCEPTION: main
10-17 00:41:04.260: E/AndroidRuntime(27450): java.lang.NoClassDefFoundError: org.apache.commons.io.FileUtils
10-17 00:41:04.260: E/AndroidRuntime(27450):    at com.abc.abc.TT_details_canton$14.onClick(TT_details_canton.java:575)
10-17 00:41:04.260: E/AndroidRuntime(27450):    at android.view.View.performClick(View.java:4223)
10-17 00:41:04.260: E/AndroidRuntime(27450):    at android.view.View$PerformClick.run(View.java:17275)
10-17 00:41:04.260: E/AndroidRuntime(27450):    at android.os.Handler.handleCallback(Handler.java:615)
10-17 00:41:04.260: E/AndroidRuntime(27450):    at android.os.Handler.dispatchMessage(Handler.java:92)
10-17 00:41:04.260: E/AndroidRuntime(27450):    at android.os.Looper.loop(Looper.java:137)
10-17 00:41:04.260: E/AndroidRuntime(27450):    at android.app.ActivityThread.main(ActivityThread.java:4898)
10-17 00:41:04.260: E/AndroidRuntime(27450):    at java.lang.reflect.Method.invokeNative(Native Method)
10-17 00:41:04.260: E/AndroidRuntime(27450):    at java.lang.reflect.Method.invoke(Method.java:511)
10-17 00:41:04.260: E/AndroidRuntime(27450):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1008)
10-17 00:41:04.260: E/AndroidRuntime(27450):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:775)
10-17 00:41:04.260: E/AndroidRuntime(27450):    at dalvik.system.NativeStart.main(Native Method)

整个晚上我一直坚持这个.有没有办法复制文件？

Answer 1

经过以下方式修改后,它运行良好:

    button1_save.setOnClickListener(new OnClickListener() 
    {
        public void onClick(View v) 
        {
            String sourcePath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/TongueTwister/tt_temp.3gp";
            File source = new File(sourcePath);

            String destinationPath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/TongueTwister/tt_1A.3gp";
            File destination = new File(destinationPath);
            try 
            {
                FileUtils.copyFile(source, destination);
            } 
            catch (IOException e) 
            {
                e.printStackTrace();
            }
        }
    }); 

Answer 2

在API level 29中，android添加了FileUtils类，该类具有复制功能。

使用此代码复制您的文件：-

public void copyFile(File source, File destination) throws IOException {
    FileUtils.copy(new FileInputStream(source), new FileOutputStream(destination));
}

如果Android Studio没有找到FileUtils类，则意味着您的compileSdkVersion低于29，在这种情况下，您必须升级您的compileSdkVersion。

要升级，请转到应用程序级 build.gradle 文件并将旧的compileSdkVersion替换为 29

像这样

compileSdkVersion 29

有关FileUtils类的更多信息，请访问 Android 开发者网站 https://developer.android.com/reference/android/os/FileUtils