android 清理緩存

備忘：清理軟件緩存功能的代碼

個人測試了第二種方法，是有效果的

清理軟件緩存

一種帶root權限的：
Class c1 = Class.forName("android.content.pm.IPackageDataObserver");
Method method = pm.getClass().getMethod("deleteApplicationCacheFiles", String.class,IPackageDataObserver.class);
method.invoke(pm, packageName,new IPackageDataObserver.Stub(){
@Override
public void onRemoveCompleted(String packageName,
boolean succeeded) throws RemoteException {
// TODO Auto-generated method stub
}
});
<uses-permission android:name="android.permission.DELETE_CACHE_FILES" />

另外一種是不用root權限;一鍵清理：

權限：<uses-permission android:name="android.permission.CLEAR_APP_CACHE" />

private static long getEnvironmentSize() {
        File localFile = Environment.getDataDirectory();
        long l1;
        if (localFile == null)
            l1 = 0L;
        String str = localFile.getPath();
        StatFs localStatFs = new StatFs(str);
        long l2 = localStatFs.getBlockSize();
        l1 = localStatFs.getBlockCount() * l2;
        return l1;
    }
    public static void clear(Activity activity) {
        try {
            PackageManager pm = activity.getPackageManager();
            Method localMethod = pm.getClass().getMethod("freeStorageAndNotify", Long.TYPE, IPackageDataObserver.class);
            Long localLong = Long.valueOf(getEnvironmentSize() - 1L);
            Object[] arrayOfObject = new Object[2];
            arrayOfObject[0] = localLong;
            localMethod.invoke(pm, localLong, new IPackageDataObserver.Stub() {
                public void onRemoveCompleted(String packageName, boolean succeeded) throws RemoteException {
                    Log.e("onRemoveCompleted,packageName="+packageName+",succeeded="+succeeded);
                }
            });
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
    }
}

可能會遇到IPackageDataObserver這個無法導進去，自己寫一個IPackageDataObserver.aidl，內容如下：
package android.content.pm;

/**
 * API for package data change related callbacks from the Package Manager.
 * Some usage scenarios include deletion of cache directory, generate
 * statistics related to code, data, cache usage(TODO)
 * {@hide}
 */
oneway interface IPackageDataObserver {
    void onRemoveCompleted(in String packageName, boolean succeeded);
}放在src包下就行了。