Android清理设备内存详细完整示例(一)

MainActivity如下:

package come.on;import android.app.Activity;import android.content.Context;import android.content.Intent;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;/** * Demo描述: * 内存清理及内存工具类 * 具体代码参见工具类MemoryUtils *  */public class MainActivity extends Activity {private Button mButton;private Context mContext;private EditText mEditText;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        init();    }        private void init(){    mContext=this;    Intent intent=new Intent("come.on.service");    //该Service无用,可去掉    startService(intent);        mEditText=(EditText) findViewById(R.id.editText);    mButton=(Button) findViewById(R.id.button);    mButton.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {        MemoryUtils.cleanMemory(mContext,mEditText);}});    }   }

MemoryUtils如下:

package come.on;import java.util.List;import java.io.FileReader;import android.os.Process;import java.io.IOException;import java.io.BufferedReader;import android.widget.EditText;import android.content.Context;import java.io.InputStreamReader;import android.app.ActivityManager;import android.content.ComponentName;import android.app.ActivityManager.MemoryInfo;import android.app.ActivityManager.RunningTaskInfo;import android.app.ActivityManager.RunningAppProcessInfo;/** * 文档描述: * 内存工具类 *  * 包括内容: * 1 内存清理即杀掉进程的几种方式 * 2 获取内存总大小及其可用大小 * 3 判断栈顶Activity名及其所属进程名 *  * 注意权限: * <uses-permission android:name="android.permission.GET_TASKS"/>   * <uses-permission android:name="android.permission.KILL_BACKGROUND_PROCESSES" /> *  * 文档日期: * 2014年5月30日10:01:55 * */public class MemoryUtils {//----------> 以下为杀掉进程的几种方式public static void cleanMemory(Context context,EditText editText) {long beforeCleanMemory=getAvailMemory(context);System.out.println("---> 清理前可用内存大小:"+beforeCleanMemory+"M");ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);RunningAppProcessInfo runningAppProcessInfo = null;List<RunningAppProcessInfo> runningAppProcessInfoList = activityManager.getRunningAppProcesses();for (int i = 0; i < runningAppProcessInfoList.size(); ++i) {runningAppProcessInfo = runningAppProcessInfoList.get(i);String processName = runningAppProcessInfo.processName;//调用杀掉进程的方法System.out.println("---> 开始清理:"+processName);killProcessByRestartPackage(context, processName);}long afterCleanMemory=getAvailMemory(context);System.out.println("---> 清理后可用内存大小:"+afterCleanMemory+"M");System.out.println("---> 节约内存大小:"+(afterCleanMemory-beforeCleanMemory)+"M");editText.setText("共清理:"+(afterCleanMemory-beforeCleanMemory)+"M");}//利用activityManager.restartPackage()方法杀死进程//该方法实际调用了activityManager.killBackgroundProcesses()方法public static void killProcessByRestartPackage(Context context,String packageName) {ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);activityManager.restartPackage(packageName);System.gc();}//利用Process.killProcess(pid)杀死进程//注意事项://1 该方式可自杀,即杀掉本进程//2 该方式可杀掉其他普通应用进程//3 该方式不可杀掉系统级应用即system/app应用public static void killProcessBykillProcess(int pid){Process.killProcess(pid);}//利用adb shell命令杀死进程public static void killProcessByAdbShell(int pid) {String cmd = "adb shell kill -9 " + pid;System.out.println("-------> cmd=" + cmd);try {java.lang.Process process = Runtime.getRuntime().exec(cmd);InputStreamReader inputStreamReader = new InputStreamReader(process.getInputStream());BufferedReader bufferedReader = new BufferedReader(inputStreamReader);String line = null;while ((line = bufferedReader.readLine()) != null) {System.out.println("----> exec shell:" + line);}bufferedReader.close();} catch (IOException e) {e.printStackTrace();}}  //利用su进程的命令方式杀死进程 //1 得到su进程(super进程) //  Runtime.getRuntime().exec("su"); //2 利用su进程执行命令 //  process.getOutputStream().write(cmd.getBytes());public static void killProcessBySu(int pid) {try {java.lang.Process process = Runtime.getRuntime().exec("su");String cmd = "kill -9 " + pid;System.out.println("-------> cmd = " + cmd);process.getOutputStream().write(cmd.getBytes());if ((process.waitFor() != 0)) {System.out.println("-------> su.waitFor()!= 0");} else {System.out.println("------->  su.waitFor()==0 ");}} catch (Exception e) {e.printStackTrace();}}//----------> 以上为杀掉进程的几种方式//获取当前进程名public static String getCurrentProcessName(Context context) {int pid = android.os.Process.myPid();ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);for (RunningAppProcessInfo runningAppProcessInfo : activityManager.getRunningAppProcesses()) {if (runningAppProcessInfo.pid == pid) {                String processName=runningAppProcessInfo.processName;return processName;}}return null;}//获取栈顶Activity名称public static String getTopActivityName(Context context) {String topActivityName = null;ActivityManager activityManager = (ActivityManager) (context.getSystemService(android.content.Context.ACTIVITY_SERVICE));List<RunningTaskInfo> runningTaskInfos = activityManager.getRunningTasks(1);if (runningTaskInfos != null) {ComponentName f = runningTaskInfos.get(0).topActivity;String topActivityClassName = f.getClassName();String temp[] = topActivityClassName.split("\\.");topActivityName = temp[temp.length - 1];}return topActivityName;}//获取栈顶Activity所属进程的名称public static String getTopActivityProcessName(Context context) {String processName = null;ActivityManager activityManager = (ActivityManager) (context.getSystemService(android.content.Context.ACTIVITY_SERVICE));List<RunningTaskInfo> runningTaskInfos = activityManager.getRunningTasks(1);if (runningTaskInfos != null) {ComponentName componentName = runningTaskInfos.get(0).topActivity;String topActivityClassName = componentName.getClassName();int index = topActivityClassName.lastIndexOf(".");processName = topActivityClassName.substring(0, index);}return processName;}//获取内存总大小public static long getTotalMemory() {// 系统的内存信息文件String filePath = "/proc/meminfo";String lineString;String[] stringArray;long totalMemory = 0;try {FileReader fileReader = new FileReader(filePath);BufferedReader bufferedReader = new BufferedReader(fileReader,1024 * 8);// 读取meminfo第一行,获取系统总内存大小lineString = bufferedReader.readLine();// 按照空格拆分stringArray = lineString.split("\\s+");// 获得系统总内存,单位KBtotalMemory = Integer.valueOf(stringArray[1]).intValue();bufferedReader.close();} catch (IOException e) {}return totalMemory / 1024;}//获取可用内存大小public static long getAvailMemory(Context context) {ActivityManager activityManager=(ActivityManager)context.getSystemService(Context.ACTIVITY_SERVICE);MemoryInfo memoryInfo = new MemoryInfo();activityManager.getMemoryInfo(memoryInfo);return memoryInfo.availMem / (1024 * 1024);}}

ServiceSubclass如下:

package come.on;import android.app.Service;import android.content.Intent;import android.os.IBinder;public class ServiceSubclass extends Service {@Overridepublic IBinder onBind(Intent intent) {return null;}@Overridepublic void onCreate() {super.onCreate();System.out.println("---> Service的 onCreate()");}@Overridepublic void onStart(Intent intent, int startId) {super.onStart(intent, startId);System.out.println("---> Service的 onStart()");}}

main.xml如下:

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"   >    <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="测试内存清理"         android:layout_centerHorizontal="true"        android:layout_marginTop="25dip"        android:textSize="20sp"     />        <EditText         android:id="@+id/editText"        android:layout_width="160dip"        android:layout_height="50dip"        android:layout_centerHorizontal="true"        android:layout_marginTop="100dip"        android:gravity="center"        android:textSize="20sp"        />        <Button         android:id="@+id/button"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="清理内存"         android:layout_centerInParent="true"         android:textSize="20sp"        />    </RelativeLayout>

AndroidManifest.xml如下:

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="come.on"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk android:minSdkVersion="10" />                    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />    <uses-permission android:name="android.permission.ACCESS_CHECKIN_PROPERTIES" />    <uses-permission android:name="android.permission.RECORD_AUDIO" />    <uses-permission android:name="android.permission.INTERNET" />    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />    <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />    <uses-permission android:name="android.permission.READ_PHONE_STATE" />    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />    <uses-permission android:name="android.permission.KILL_BACKGROUND_PROCESSES" />    <uses-permission android:name="android.permission.GET_TASKS"/>                  <application        android:icon="@drawable/a"        android:label="@string/app_name" >        <activity            android:label="@string/app_name"            android:name=".MainActivity" >            <intent-filter >                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>        <service android:name=".ServiceSubclass">            <intent-filter>                <action android:name="come.on.service"/>            </intent-filter>        </service>    </application></manifest>