一键保存可绘制文件夹中的多张图片

Question

I want to download multiple images from my app drawable with one button click and save it in device internal/external storage of my Android app.

How do I achieve this?

UPDATE

I tried it, but I'm having one issue.

 downloadTest.setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick (View v){
            //path here is for internal storage (Option 2), replace it with the other line above from Option 1 to save images to SD card
            String path = new File(getFilesDir(), "/Space Wallpapers").getAbsolutePath();

            //ids are drawables resource ids
            int[] ids = new int[]{ R.drawable.abduction,
                    R.drawable.green_nightstreak,
                    R.drawable.hero,
                    R.drawable.ic_night,
                    R.drawable.light_streak,
                    R.drawable.moon_with_stars,
                    R.drawable.orange_nightstreak,};

            int i = 1;
            for (int res : ids) {
                //Creates the bitmap object from the given resource
                Bitmap b = BitmapFactory.decodeResource(getResources(), res);

                File file = new File(path, "image" + i + ".PNG");

                //This creates the file and it's parent if doesn't exist
                file.getParentFile().mkdirs();

                try {
                    FileOutputStream fileOut = new FileOutputStream(file);
                    b.compress(Bitmap.CompressFormat.PNG, 100, fileOut);
                    fileOut.close();

                } catch (Exception e) {
                    e.printStackTrace();
                }

                i++;
            }
        };
    });

The issue is that it's not the images are not downloading.

**This is what my "Run" log is showing **

    D/ViewRootImpl@372fd66[TestActivity]: ViewPostImeInputStage processPointer 0
D/ViewRootImpl@372fd66[TestActivity]: ViewPostImeInputStage processPointer 1
W/System.err: java.io.FileNotFoundException: /data/user/0/com.khumomashapa.notes.debug/files/Space Wallpapers/image1.PNG (Is a directory)
        at java.io.FileOutputStream.open(Native Method)
W/System.err:     at java.io.FileOutputStream.<init>(FileOutputStream.java:221)
        at java.io.FileOutputStream.<init>(FileOutputStream.java:169)
        at com.khumomashapa.notes.activities.TestActivity$1.onClick(TestActivity.java:54)
        at android.view.View.performClick(View.java:6205)
        at android.widget.TextView.performClick(TextView.java:11103)
W/System.err:     at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1073)
        at android.view.View$PerformClick.run(View.java:23653)
        at android.os.Handler.handleCallback(Handler.java:751)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6682)
W/System.err:     at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1520)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1410)
W/System.err: java.io.FileNotFoundException: /data/user/0/com.khumomashapa.notes.debug/files/Space Wallpapers/image2.PNG (Is a directory)
        at java.io.FileOutputStream.open(Native Method)
W/System.err:     at java.io.FileOutputStream.<init>(FileOutputStream.java:221)
        at java.io.FileOutputStream.<init>(FileOutputStream.java:169)
        at com.khumomashapa.notes.activities.TestActivity$1.onClick(TestActivity.java:54)
        at android.view.View.performClick(View.java:6205)
        at android.widget.TextView.performClick(TextView.java:11103)
        at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1073)
W/System.err:     at android.view.View$PerformClick.run(View.java:23653)
        at android.os.Handler.handleCallback(Handler.java:751)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:154)
W/System.err:     at android.app.ActivityThread.main(ActivityThread.java:6682)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1520)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1410)
W/System.err: java.io.FileNotFoundException: /data/user/0/com.khumomashapa.notes.debug/files/Space Wallpapers/image3.PNG (Is a directory)
W/System.err:     at java.io.FileOutputStream.open(Native Method)
        at java.io.FileOutputStream.<init>(FileOutputStream.java:221)
        at java.io.FileOutputStream.<init>(FileOutputStream.java:169)
        at com.khumomashapa.notes.activities.TestActivity$1.onClick(TestActivity.java:54)
        at android.view.View.performClick(View.java:6205)
        at android.widget.TextView.performClick(TextView.java:11103)
        at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1073)
        at android.view.View$PerformClick.run(View.java:23653)
        at android.os.Handler.handleCallback(Handler.java:751)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6682)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1520)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1410)
W/System.err: java.io.FileNotFoundException: /data/user/0/com.khumomashapa.notes.debug/files/Space Wallpapers/image4.PNG (Is a directory)
        at java.io.FileOutputStream.open(Native Method)
        at java.io.FileOutputStream.<init>(FileOutputStream.java:221)
        at java.io.FileOutputStream.<init>(FileOutputStream.java:169)
        at com.khumomashapa.notes.activities.TestActivity$1.onClick(TestActivity.java:54)
        at android.view.View.performClick(View.java:6205)
        at android.widget.TextView.performClick(TextView.java:11103)
        at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1073)
        at android.view.View$PerformClick.run(View.java:23653)
        at android.os.Handler.handleCallback(Handler.java:751)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6682)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1520)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1410)
W/System.err: java.io.FileNotFoundException: /data/user/0/com.khumomashapa.notes.debug/files/Space Wallpapers/image5.PNG (Is a directory)
        at java.io.FileOutputStream.open(Native Method)
        at java.io.FileOutputStream.<init>(FileOutputStream.java:221)
W/System.err:     at java.io.FileOutputStream.<init>(FileOutputStream.java:169)
        at com.khumomashapa.notes.activities.TestActivity$1.onClick(TestActivity.java:54)
        at android.view.View.performClick(View.java:6205)
        at android.widget.TextView.performClick(TextView.java:11103)
        at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1073)
        at android.view.View$PerformClick.run(View.java:23653)
        at android.os.Handler.handleCallback(Handler.java:751)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6682)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1520)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1410)
W/System.err: java.io.FileNotFoundException: /data/user/0/com.khumomashapa.notes.debug/files/Space Wallpapers/image6.PNG (Is a directory)
        at java.io.FileOutputStream.open(Native Method)
        at java.io.FileOutputStream.<init>(FileOutputStream.java:221)
        at java.io.FileOutputStream.<init>(FileOutputStream.java:169)
        at com.khumomashapa.notes.activities.TestActivity$1.onClick(TestActivity.java:54)
        at android.view.View.performClick(View.java:6205)
        at android.widget.TextView.performClick(TextView.java:11103)
        at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1073)
        at android.view.View$PerformClick.run(View.java:23653)
        at android.os.Handler.handleCallback(Handler.java:751)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6682)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1520)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1410)
W/System.err: java.io.FileNotFoundException: /data/user/0/com.khumomashapa.notes.debug/files/Space Wallpapers/image7.PNG (Is a directory)
        at java.io.FileOutputStream.open(Native Method)
        at java.io.FileOutputStream.<init>(FileOutputStream.java:221)
        at java.io.FileOutputStream.<init>(FileOutputStream.java:169)
W/System.err:     at com.khumomashapa.notes.activities.TestActivity$1.onClick(TestActivity.java:54)
        at android.view.View.performClick(View.java:6205)
        at android.widget.TextView.performClick(TextView.java:11103)
        at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1073)
        at android.view.View$PerformClick.run(View.java:23653)
        at android.os.Handler.handleCallback(Handler.java:751)
        at android.os.Handler.dispatchMessage(Handler.java:95)
W/System.err:     at android.os.Looper.loop(Looper.java:154)
W/System.err:     at android.app.ActivityThread.main(ActivityThread.java:6682)
W/System.err:     at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1520)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1410)
I/Choreographer: Skipped 134 frames!  The application may be doing too much work on its main thread.

Answer 1

I assume that by "download" you mean save/export. Then, this code should be working fine.

Option 1:

If you want to save images to external storage (SD card) add this line above the code:

String path = new File(Environment.getExternalStorageDirectory(), "Images").getAbsolutePath();

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

Option 2

If you want to save images to internal storage, just add:

String path = new File(getFilesDir(), "Images").getAbsolutePath() ;

Then:

yourButton.setOnClickListener(new View.OnClickListener(){
    @Override
    public void onClick (View v){

    //path here is for internal storage (Option 2), replace it with the other line above from Option 1 to save images to SD card
    String path = new File(getFilesDir(), "Images").getAbsolutePath();


    //ids are drawables resource ids
    int[] ids = new int[]{R.drawable.imageId1, R.drawable.imageId2, R.drawable.imageId3};

    int i = 1;
    for (int res : ids) {
        //Creates the bitmap object from the given resource
        Bitmap b = BitmapFactory.decodeResource(getResources(), res);

        File file = new File(path, "image" + i + ".PNG");

        //This creates the file and it's parent if doesn't exist
        file.getParentFile().mkdirs();

        try {
            FileOutputStream fileOut = new FileOutputStream(file);
            b.compress(Bitmap.CompressFormat.PNG, 100, fileOut);
            fileOut.close;

        } catch (Exception e) {
            e.printStackTrace();
        }

        i++;
    }
});

Output:

R.drawable.imageId1 will be saved to path/image1.PNG

R.drawable.imageId2 will be saved to path/image2.PNG

R.drawable.imageId3 will be saved to path/image3.PNG