Android清理设备内存详细完整示例(一)

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() {
@Override
public void onClick(View v) {
MemoryUtils.cleanMemory(mContext,mEditText);
}
});
}

}

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KB
totalMemory = 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);
}

}

package come.on;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;

public class ServiceSubclass extends Service {

@Override
public IBinder onBind(Intent intent) {
return null;
}

@Override
public void onCreate() {
super.onCreate();
System.out.println("---> Service的 onCreate()");
}

@Override
public void onStart(Intent intent, int startId) {
super.onStart(intent, startId);
System.out.println("---> Service的 onStart()");
}

}

<?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>

<?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>