问题
I have an image that I got from the user's album and I saved it in a folder.
here is the code:
filename = "pippo.png";
try {
ContextWrapper cw = new ContextWrapper(getApplicationContext());
File directory = cw.getDir("imageDir", Context.MODE_PRIVATE);
// Create imageDir
File myPath = new File(directory,filename);
FileOutputStream out = new FileOutputStream(myPath);
theImage.compress(Bitmap.CompressFormat.PNG, 90, out);
out.flush();
out.close();
Log.d("Image","saved success");
picture = directory.getAbsolutePath();
} catch (Exception e) {
e.printStackTrace();
Log.d("Image","saved failed");
}
Then i read the image and change its name by that code:
if(comingIntent.hasExtra("FILEPATH"))
{
filePath = comingIntent.getStringExtra("FILEPATH");
String filename = "pippo.png";
try {
File f = new File(filePath, filename);
Bitmap b = BitmapFactory.decodeStream(new FileInputStream(f));
playerImage.setImageBitmap(b);
File newfile = new File(filePath,username+".png");
f.renameTo(newfile);
Log.d("Image","first load succcess");
}
catch (FileNotFoundException e)
{
e.printStackTrace();
Log.d("Image","first load failed");
}
But then when I try to reload the image with its new name, I get a file not found exception, that's the code:
try {
File f = new File(filePath, username+".png");
Bitmap b = BitmapFactory.decodeStream(new FileInputStream(f));
playerImage.setImageBitmap(b);
Log.d("Image","second load succcess"); }
catch (FileNotFoundException e)
{
e.printStackTrace();
Log.d("Image","second load failed"); }
That's the Log error:
08-09 20:23:50.730 15052-15052/? W/System.err: java.io.FileNotFoundException: lol1.png: open failed: ENOENT (No such file or directory) 08-09 20:23:50.743 15052-15052/? W/System.err:
at libcore.io.IoBridge.open(IoBridge.java:452) at java.io.FileInputStream.(FileInputStream.java:76) at com.example.abzo.socsoc.PlayerHomePage.onCreate(PlayerHomePage.java:103) at android.app.Activity.performCreate(Activity.java:6285) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1108) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2414) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2521) at android.app.ActivityThread.access$900(ActivityThread.java:150) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1383) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5517) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) Caused by: android.system.ErrnoException: open failed: ENOENT (No such file or directory) at libcore.io.Posix.open(Native Method) at libcore.io.BlockGuardOs.open(BlockGuardOs.java:186) at libcore.io.IoBridge.open(IoBridge.java:438) ... 14 more 08-09 20:23:50.744 15052-15052/? D/Image: second load failed
回答1:
As we discussed in the comments, I believe your renameTo() is not working because of some type of hold on the file, but you did not post your full code so I cannot be completely sure.
With the code you provided, I have created a MainActivity that accomplishes a rename of the file you noted that was stored in Internal Storage (i.e. pippo.png). The successful rename is proved in the debug logs when you run the Activity.
Note: In my solution below I am just creating Files and placing them where you said they are supposed to go to provide you an answer of how renameTo() should/can be used in your app, I am not actually working with images as you did not provide me with your code that you use to access the images. I'm sure you realize this, but you will need to be sure the image you are working with is being selected correctly by the user and the path is accurate for my example to work when you plug it into your real application.
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String imageFilename = "pippo.png";
//example username, I am not sure how you get this info
String exampleUsername = "user1";
try {
ContextWrapper cw = new ContextWrapper(getApplicationContext());
File directory = cw.getDir("imageDir", Context.MODE_PRIVATE);
//check that we are good here...
if(directory.exists())
Log.d("ImageTAG", "'imageDir' exists");
// create imageDir
File completeImagePath = new File(directory, imageFilename);
//write file
FileOutputStream out = new FileOutputStream(completeImagePath);
out.flush();
out.close();
//check to ensure complete image path exists... it should
if(completeImagePath.exists())
Log.d("ImageTAG", "'completeImagePath' exists");
//show full path on device
Log.d("ImageTAG", "Image saved success, complete Image Path: " +
completeImagePath.getAbsolutePath());
//redeclaration of file here is not needed, but added for clarity
File from = new File(completeImagePath.getAbsolutePath());
//what you are renaming the file to
File to = new File(directory, exampleUsername + ".png");
//now rename
Boolean success = from.renameTo(to);
Log.d("ImageTAG", "Successful Rename: "+success.toString()+"| File is now named: "+to.getPath());
} catch (Exception e) {
e.printStackTrace();
Log.d("ImageTAG","saved failed");
}
}
}
来源：https://stackoverflow.com/questions/51773785/how-to-rename-a-file-in-internal-storage