luongkhanh luongkhanh - 1 month ago 22
Android Question

FileNotFoundException: /storage/emulated/0/JsonParseTutorialCache: open failed: ENOENT (No such file or directory)

I'm using GridView to load json data holding images. When I built project it happened some exceptions

AndroidManifest.xml:

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


FileCache class:

public class FileCache {

private File cacheDir;

public FileCache(Context context) {
// Find the dir to save cached images
if (android.os.Environment.getExternalStorageState().equals(
android.os.Environment.MEDIA_MOUNTED))
cacheDir = new File(
android.os.Environment.getExternalStorageDirectory(),
"JsonParseTutorialCache");
else
cacheDir = context.getCacheDir();
if (!cacheDir.exists())
cacheDir.mkdirs();
}

public File getFile(String url) throws IOException {
String filename = String.valueOf(url.hashCode());
// String filename = URLEncoder.encode(url);
File f = new File(cacheDir, filename);
f.createNewFile();
return f;
}

public void clear() {
File[] files = cacheDir.listFiles();
if (files == null)
return;
for (File f : files)
f.delete();
}


}

Logcat:

W/System.err: java.io.IOException: open failed: ENOENT (No such file or directory)
W/System.err: at java.io.File.createNewFile(File.java:939)
W/System.err: at com.totoroads.android.app.FileCache.getFile(FileCache.java:33)
W/System.err: at com.totoroads.android.app.ImageLoader.getBitmap(ImageLoader.java:64)
W/System.err: at com.totoroads.android.app.ImageLoader.access$000(ImageLoader.java:29)
W/System.err: at com.totoroads.android.app.ImageLoader$PhotosLoader.run(ImageLoader.java:155)
W/System.err: at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:423)
W/System.err: at java.util.concurrent.FutureTask.run(FutureTask.java:237)
W/System.err: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
W/System.err: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
W/System.err: at java.lang.Thread.run(Thread.java:818)
W/System.err: Caused by: android.system.ErrnoException: open failed: ENOENT (No such file or directory)
W/System.err: at libcore.io.Posix.open(Native Method)
W/System.err: at libcore.io.BlockGuardOs.open(BlockGuardOs.java:186)
W/System.err: at java.io.File.createNewFile(File.java:932)
W/System.err: ... 9 more


I want to download, read and display images on GridView, How to fix those exceptions?

Answer

The code in FileCache.java is

public File getFile(String url) {
    String filename = String.valueOf(url.hashCode());
    // String filename = URLEncoder.encode(url);
    File f = new File(cacheDir, filename);
    return f;
}

A new file object has been created, but the file may not exist. So, replace the above code with

public File getFile(String url) {
    String filename = String.valueOf(url.hashCode());
    // String filename = URLEncoder.encode(url);
    File f = new File(cacheDir, filename);
    f.createNewFile();
    return f;
}

Hope, it helps.

Edit : As you're running your code on >= Android 6.0, you gotta request for permission to access External Storage at runtime. Adding those in AndroidManifest.xml isn't enough. You can use this link on how to do it.

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