Android清理设备内存具体完整演示样例(一)

MainActivity例如以下:

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描写叙述:
 * 内存清理及内存工具类
 * 详细代码參见工具类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);
			}
		});
    }

}

MemoryUtils例如以下:

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;

/**
 * 文档描写叙述:
 * 内存工具类
 *
 * 包含内容:
 * 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 推断栈顶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 {

	//----------> 下面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("---> 開始清理:"+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 该方式可杀掉其它普通应用进程
	//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进程运行命令
	 //  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();
			// 依照空格拆分
			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);
	}

}

ServiceSubclass例如以下:

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()");
	}

}

main.xml例如以下:

<?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="測试内存清理"
        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例如以下:

<?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>