Android学习笔记_58_清除手机应用程序缓存

通过查看手机设置(setting)源代码，发现它里面获取应用大小和缓存大小是通过PackageManager里面的getPackageSizeInfo方法。然而此方法时私有的，因此通过反射调用此方法。里面要用到IPackageStatsObserver接口，它是一个aidl方式进行访问。

package cn.itcast.testclear;



import java.lang.reflect.Method;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import java.util.Map.Entry;

import java.util.Set;



import android.app.Activity;

import android.app.ListActivity;

import android.content.Intent;

import android.content.pm.IPackageStatsObserver;

import android.content.pm.PackageInfo;

import android.content.pm.PackageManager;

import android.content.pm.PackageStats;

import android.net.Uri;

import android.os.Bundle;

import android.os.IBinder;

import android.os.RemoteException;

import android.view.View;

import android.view.ViewGroup;

import android.widget.Adapter;

import android.widget.AdapterView;

import android.widget.AdapterView.OnItemClickListener;

import android.widget.BaseAdapter;

import android.widget.ListView;

import android.widget.TextView;



public class DemoActivity extends ListActivity {

    private PackageManager pm;

    private ListView lv;

    private MyAdapter adapter;



    private Map<String, CacheInfo> maps;



    /** Called when the activity is first created. */

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        pm = getPackageManager();

        maps = new HashMap<String, CacheInfo>();

        lv = getListView();



        // lv.setAdapter(adapter);



        // 1.获取所有的安装好的应用程序



        List<PackageInfo> packageinfos = pm.getInstalledPackages(PackageManager.GET_UNINSTALLED_PACKAGES);

        for (PackageInfo info : packageinfos) {

            String name = info.applicationInfo.loadLabel(pm).toString();

            String packname = info.packageName;

            CacheInfo cacheinfo = new CacheInfo();

            cacheinfo.setName(name);

            cacheinfo.setPackname(packname);

            maps.put(packname, cacheinfo);

            getAppSize(packname);

        }



        adapter = new MyAdapter();

        lv.setAdapter(adapter);



        lv.setOnItemClickListener(new OnItemClickListener() {



            public void onItemClick(AdapterView<?> parent, View view,

                    int position, long id) {

                /*

                 * 

                 * <intent-filter> <action android:name="android.settings.APPLICATION_DETAILS_SETTINGS" /> <category

                 * android:name="android.intent.category.DEFAULT" /> <data android:scheme="package" /> </intent-filter>

                 */

                /*

                 * 2.2 <intent-filter> <action android:name="android.intent.action.VIEW" /> <category android:name="android.intent.category.DEFAULT"

                 * /> <category android:name="android.intent.category.VOICE_LAUNCH" /> </intent-filter>

                 */

                System.out.println("haha");

                Intent intent = new Intent();

                intent.setAction("android.intent.action.VIEW");

                intent.addCategory("android.intent.category.DEFAULT");

                intent.addCategory("android.intent.category.VOICE_LAUNCH");

                CacheInfo info = (CacheInfo) lv.getItemAtPosition(position);

                intent.putExtra("pkg", info.getPackname());//传递所在包

                startActivity(intent);

            }

        });



    }



    /**

     * 根据包名获取应用程序的体积信息 注意: 这个方法是一个异步的方法 程序的体积要花一定时间才能获取到.

     * 

     * @param packname

     */

    private void getAppSize(final String packname) {

        try {

            Method method = PackageManager.class.getMethod("getPackageSizeInfo", new Class[]{String.class,

                            IPackageStatsObserver.class});

            method.invoke(pm, new Object[]{packname,

                    new IPackageStatsObserver.Stub() {

                        public void onGetStatsCompleted(PackageStats pStats,boolean succeeded) throws RemoteException {

                            // 注意这个操作是一个异步的操作

                            long cachesize = pStats.cacheSize;

                            long codesize = pStats.codeSize;

                            long datasize = pStats.dataSize;

                            CacheInfo info = maps.get(packname);

                            info.setCache_size(TextFormater.getDataSize(cachesize));

                            info.setData_size(TextFormater.getDataSize(datasize));

                            info.setCode_size(TextFormater.getDataSize(codesize));

                            maps.put(packname, info);



                        }

                    }});



        } catch (Exception e) {

            e.printStackTrace();

        }

    }



    private class MyAdapter extends BaseAdapter {



        private Set<Entry<String, CacheInfo>> sets;

        private List<CacheInfo> cacheinfos;



        public MyAdapter() {

            sets = maps.entrySet();

            cacheinfos = new ArrayList<CacheInfo>();

            for (Entry<String, CacheInfo> entry : sets) {

                cacheinfos.add(entry.getValue());

            }



        }



        public int getCount() {

            return cacheinfos.size();

        }



        public Object getItem(int position) {

            return cacheinfos.get(position);

        }



        public long getItemId(int position) {

            return position;

        }



        public View getView(int position, View convertView, ViewGroup parent) {

            View view = null;

            CacheInfo info = cacheinfos.get(position);

            if (convertView == null) {

                view = View.inflate(DemoActivity.this, R.layout.item, null);

            } else {

                view = convertView;

            }

            TextView tv_cache_size = (TextView) view.findViewById(R.id.tv_cache_size);

            TextView tv_code_size = (TextView) view.findViewById(R.id.tv_code_size);

            TextView tv_data_size = (TextView) view.findViewById(R.id.tv_data_size);

            TextView tv_name = (TextView) view.findViewById(R.id.tv_name);

            tv_cache_size.setText(info.getCache_size());

            tv_code_size.setText(info.getCode_size());

            tv_data_size.setText(info.getData_size());

            tv_name.setText(info.getName());

            return view;

        }



    }



}

package cn.itcast.testclear;



public class CacheInfo {

    //应用名称

    private String name;

    //应用所在包名

    private String packname;

    //

    private String code_size;

    //数据大小

    private String data_size;

    //缓存大小

    private String cache_size;

}

public class TextFormater {



    /**

     * 返回byte的数据大小对应的文本

     * 

     * @param size

     * @return

     */

    public static String getDataSize(long size) {

        if (size < 0) {

            size = 0;

        }

        DecimalFormat formater = new DecimalFormat("####.00");

        if (size < 1024) {

            return size + "bytes";

        } else if (size < 1024 * 1024) {

            float kbsize = size / 1024f;

            return formater.format(kbsize) + "KB";

        } else if (size < 1024 * 1024 * 1024) {

            float mbsize = size / 1024f / 1024f;

            return formater.format(mbsize) + "MB";

        } else if (size < 1024 * 1024 * 1024 * 1024) {

            float gbsize = size / 1024f / 1024f / 1024f;

            return formater.format(gbsize) + "GB";

        } else {

            return "size: error";

        }



    }



    /**

     * 返回kb的数据大小对应的文本

     * 

     * @param size

     * @return

     */

    public static String getKBDataSize(long size) {

        if (size < 0) {

            size = 0;

        }

        return getDataSize(size * 1024);

    }

}

 

aidl文件：IPackageStatsObserver.aidl

/*

**

** Copyright 2007, 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.content.pm;



import android.content.pm.PackageStats;

/**

 * 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 IPackageStatsObserver {

    

    void onGetStatsCompleted(in PackageStats pStats, boolean succeeded);

}

PackageStats.aidl

/* //device/java/android/android/view/WindowManager.aidl

**

** Copyright 2007, 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.content.pm;



parcelable PackageStats;