alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Android example source code file (StorageManager.java)

This example Android source code file (StorageManager.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" TM.

Java - Android tags/keywords

android, arraylist, exception, failed, handler, io, listenerdelegate, message, mountservicebinderlistener, os, remoteexception, storageevent, storageeventlistener, storagemanager, storagestatechangedstorageevent, string, umsconnectionchangedstorageevent, util, utilities, utils

The StorageManager.java Android example source code

/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.os.storage;

import android.content.Context;
import android.os.Binder;
import android.os.Bundle;
import android.os.Looper;
import android.os.Parcelable;
import android.os.ParcelFileDescriptor;
import android.os.Process;
import android.os.RemoteException;
import android.os.Handler;
import android.os.Message;
import android.os.ServiceManager;
import android.os.storage.IMountService;
import android.os.storage.IMountServiceListener;
import android.util.Log;
import android.util.SparseArray;

import java.io.FileDescriptor;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;

/**
 * StorageManager is the interface to the systems storage service.
 * Get an instance of this class by calling
 * {@link android.content.Context#getSystemService(java.lang.String)} with an argument
 * of {@link android.content.Context#STORAGE_SERVICE}.
 *
 * @hide
 *
 */

public class StorageManager
{
    private static final String TAG = "StorageManager";

    /*
     * Our internal MountService binder reference
     */
    private IMountService mMountService;

    /*
     * The looper target for callbacks
     */
    Looper mTgtLooper;

    /*
     * Target listener for binder callbacks
     */
    private MountServiceBinderListener mBinderListener;

    /*
     * List of our listeners
     */
    private ArrayList<ListenerDelegate> mListeners = new ArrayList();

    private class MountServiceBinderListener extends IMountServiceListener.Stub {
        public void onUsbMassStorageConnectionChanged(boolean available) {
            final int size = mListeners.size();
            for (int i = 0; i < size; i++) {
                mListeners.get(i).sendShareAvailabilityChanged(available);
            }
        }

        public void onStorageStateChanged(String path, String oldState, String newState) {
            final int size = mListeners.size();
            for (int i = 0; i < size; i++) {
                mListeners.get(i).sendStorageStateChanged(path, oldState, newState);
            }
        }
    }

    /**
     * Private base class for messages sent between the callback thread
     * and the target looper handler.
     */
    private class StorageEvent {
        public static final int EVENT_UMS_CONNECTION_CHANGED = 1;
        public static final int EVENT_STORAGE_STATE_CHANGED   = 2;

        private Message mMessage;

        public StorageEvent(int what) {
            mMessage = Message.obtain();
            mMessage.what = what;
            mMessage.obj = this;
        }

        public Message getMessage() {
            return mMessage;
        }
    }

    /**
     * Message sent on a USB mass storage connection change.
     */
    private class UmsConnectionChangedStorageEvent extends StorageEvent {
        public boolean available;

        public UmsConnectionChangedStorageEvent(boolean a) {
            super(EVENT_UMS_CONNECTION_CHANGED);
            available = a;
        }
    }

    /**
     * Message sent on volume state change.
     */
    private class StorageStateChangedStorageEvent extends StorageEvent {
        public String path;
        public String oldState;
        public String newState;

        public StorageStateChangedStorageEvent(String p, String oldS, String newS) {
            super(EVENT_STORAGE_STATE_CHANGED);
            path = p;
            oldState = oldS;
            newState = newS;
        }
    }

    /**
     * Private class containing sender and receiver code for StorageEvents.
     */
    private class ListenerDelegate {
        final StorageEventListener mStorageEventListener;
        private final Handler mHandler;

        ListenerDelegate(StorageEventListener listener) {
            mStorageEventListener = listener;
            mHandler = new Handler(mTgtLooper) {
                @Override
                public void handleMessage(Message msg) {
                    StorageEvent e = (StorageEvent) msg.obj;

                    if (msg.what == StorageEvent.EVENT_UMS_CONNECTION_CHANGED) {
                        UmsConnectionChangedStorageEvent ev = (UmsConnectionChangedStorageEvent) e;
                        mStorageEventListener.onUsbMassStorageConnectionChanged(ev.available);
                    } else if (msg.what == StorageEvent.EVENT_STORAGE_STATE_CHANGED) {
                        StorageStateChangedStorageEvent ev = (StorageStateChangedStorageEvent) e;
                        mStorageEventListener.onStorageStateChanged(ev.path, ev.oldState, ev.newState);
                    } else {
                        Log.e(TAG, "Unsupported event " + msg.what);
                    }
                }
            };
        }

        StorageEventListener getListener() {
            return mStorageEventListener;
        }

        void sendShareAvailabilityChanged(boolean available) {
            UmsConnectionChangedStorageEvent e = new UmsConnectionChangedStorageEvent(available);
            mHandler.sendMessage(e.getMessage());
        }

        void sendStorageStateChanged(String path, String oldState, String newState) {
            StorageStateChangedStorageEvent e = new StorageStateChangedStorageEvent(path, oldState, newState);
            mHandler.sendMessage(e.getMessage());
        }
    }

    /**
     * Constructs a StorageManager object through which an application can
     * can communicate with the systems mount service.
     * 
     * @param tgtLooper The {@android.os.Looper} which events will be received on.
     *
     * <p>Applications can get instance of this class by calling
     * {@link android.content.Context#getSystemService(java.lang.String)} with an argument
     * of {@link android.content.Context#STORAGE_SERVICE}.
     *
     * @hide
     */
    public StorageManager(Looper tgtLooper) throws RemoteException {
        mMountService = IMountService.Stub.asInterface(ServiceManager.getService("mount"));
        if (mMountService == null) {
            Log.e(TAG, "Unable to connect to mount service! - is it running yet?");
            return;
        }
        mTgtLooper = tgtLooper;
        mBinderListener = new MountServiceBinderListener();
        mMountService.registerListener(mBinderListener);
    }


    /**
     * Registers a {@link android.os.storage.StorageEventListener StorageEventListener}.
     *
     * @param listener A {@link android.os.storage.StorageEventListener StorageEventListener} object.
     *
     */
    public void registerListener(StorageEventListener listener) {
        if (listener == null) {
            return;
        }

        synchronized (mListeners) {
            mListeners.add(new ListenerDelegate(listener));
        }
    }

    /**
     * Unregisters a {@link android.os.storage.StorageEventListener StorageEventListener}.
     *
     * @param listener A {@link android.os.storage.StorageEventListener StorageEventListener} object.
     *
     */
    public void unregisterListener(StorageEventListener listener) {
        if (listener == null) {
            return;
        }

        synchronized (mListeners) {
            final int size = mListeners.size();
            for (int i=0 ; i<size ; i++) {
                ListenerDelegate l = mListeners.get(i);
                if (l.getListener() == listener) {
                    mListeners.remove(i);
                    break;
                }
            }
        }
    }

    /**
     * Enables USB Mass Storage (UMS) on the device.
     */
    public void enableUsbMassStorage() {
        try {
            mMountService.setUsbMassStorageEnabled(true);
        } catch (Exception ex) {
            Log.e(TAG, "Failed to enable UMS", ex);
        }
    }

    /**
     * Disables USB Mass Storage (UMS) on the device.
     */
    public void disableUsbMassStorage() {
        try {
            mMountService.setUsbMassStorageEnabled(false);
        } catch (Exception ex) {
            Log.e(TAG, "Failed to disable UMS", ex);
        }
    }

    /**
     * Query if a USB Mass Storage (UMS) host is connected.
     * @return true if UMS host is connected.
     */
    public boolean isUsbMassStorageConnected() {
        try {
            return mMountService.isUsbMassStorageConnected();
        } catch (Exception ex) {
            Log.e(TAG, "Failed to get UMS connection state", ex);
        }
        return false;
    }

    /**
     * Query if a USB Mass Storage (UMS) is enabled on the device.
     * @return true if UMS host is enabled.
     */
    public boolean isUsbMassStorageEnabled() {
        try {
            return mMountService.isUsbMassStorageEnabled();
        } catch (RemoteException rex) {
            Log.e(TAG, "Failed to get UMS enable state", rex);
        }
        return false;
    }
}

Other Android examples (source code examples)

Here is a short list of links related to this Android StorageManager.java source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.