Main.java Source code

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Here is the source code for Main.java

Source

//package com.java2s;
import android.content.Context;
import android.content.pm.PackageManager;
import android.os.Environment;

import java.io.File;
import java.io.IOException;
import static android.os.Environment.MEDIA_MOUNTED;

public class Main {
    private static final String EXTERNAL_STORAGE_PERMISSION = "android.permission.WRITE_EXTERNAL_STORAGE";

    /**
     * Returns application cache directory. Cache directory will be created on SD card
     * <i>("/Android/data/[app_package_name]/cache")</i> if card is mounted and app has appropriate permission. Else -
     * Android defines cache directory on device's file system.
     *
     * @param context Application context
     * @return Cache {@link File directory}.<br />
     * <b>NOTE:</b> Can be null in some unpredictable cases (if SD card is unmounted and
     * {@link Context#getCacheDir() Context.getCacheDir()} returns null).
     */
    public static File getCacheDirectory(Context context) {
        return getCacheDirectory(context, true);
    }

    /**
     * Returns application cache directory. Cache directory will be created on SD card
     * <i>("/Android/data/[app_package_name]/cache")</i> (if card is mounted and app has appropriate permission) or
     * on device's file system depending incoming parameters.
     *
     * @param context        Application context
     * @param preferExternal Whether prefer external location for cache
     * @return Cache {@link File directory}.<br />
     * <b>NOTE:</b> Can be null in some unpredictable cases (if SD card is unmounted and
     * {@link Context#getCacheDir() Context.getCacheDir()} returns null).
     */
    public static File getCacheDirectory(Context context, boolean preferExternal) {
        File appCacheDir = null;
        String externalStorageState;
        try {
            externalStorageState = Environment.getExternalStorageState();
        } catch (NullPointerException e) { // (sh)it happens (Issue #660)
            externalStorageState = "";
        } catch (IncompatibleClassChangeError e) { // (sh)it happens too (Issue #989)
            externalStorageState = "";
        }
        if (preferExternal && MEDIA_MOUNTED.equals(externalStorageState) && hasExternalStoragePermission(context)) {
            appCacheDir = getExternalCacheDir(context);
        }
        if (appCacheDir == null) {
            appCacheDir = context.getCacheDir();
        }
        if (appCacheDir == null) {
            String cacheDirPath = "/data/data/" + context.getPackageName() + "/cache/";
            appCacheDir = new File(cacheDirPath);
        }
        return appCacheDir;
    }

    private static boolean hasExternalStoragePermission(Context context) {
        int perm = context.checkCallingOrSelfPermission(EXTERNAL_STORAGE_PERMISSION);
        return perm == PackageManager.PERMISSION_GRANTED;
    }

    private static File getExternalCacheDir(Context context) {
        File dataDir = new File(new File(Environment.getExternalStorageDirectory(), "Android"), "data");
        File appCacheDir = new File(new File(dataDir, context.getPackageName()), "cache");
        if (!appCacheDir.exists()) {
            if (!appCacheDir.mkdirs()) {
                return null;
            }
            try {
                new File(appCacheDir, ".nomedia").createNewFile();
            } catch (IOException e) {
            }
        }
        return appCacheDir;
    }
}