安卓学习笔记之读取内存信息

安卓学习笔记之读取内存信息

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1. 通过context.getSystemService(Context.ACTIVITY_SERVICE)获得ActivityManager对象
2. 通过ActivityManager对象获得相关信息

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获取正在运行的app个数

/**     * 获取正在运行的app个数     * @return     */    public static int  getRunningAppCount(Context context) {        ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);        int count = am.getRunningAppProcesses().size();        return count;    }

获取手机可用内存信息 单位是bit

/**     * 获取手机可用内存信息 单位是bit     * @param context     */    public static long getFreeMemoryInfo(Context context){        ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);        MemoryInfo outInfo = new MemoryInfo();        am.getMemoryInfo(outInfo );        long availMem = outInfo.availMem;//      long totalMem = outInfo.totalMem;  //低版本手机不可用        return availMem;    }

获取总的可用内存 单位是bit

从/proc/meminfo目录中读取信息
MemTotal: 1031016 kB
MemFree: 13548 kB
MemShared: 0 kB
Buffers: 98064 kB
Cached: 692320 kB
SwapCached: 2244 kB
Active: 563112 kB
Inact_dirty: 309584 kB
Inact_clean: 79508 kB
Inact_target: 190440 kB
HighTotal: 130992 kB
HighFree: 1876 kB
LowTotal: 900024 kB
LowFree: 11672 kB
SwapTotal: 1052248 kB
SwapFree: 1043908 kB
Committed_AS: 332340 kB

/**     * 获取总的可用内存 单位是bit     * @return     */    public static long getTotalMemoryInfo() {        File file = new File("/proc/meminfo");        BufferedReader br = null;        try {             br = new BufferedReader(new InputStreamReader(new FileInputStream(file)));             String buff;             while ((buff = br.readLine()) != null) {                if (buff.startsWith("MemTotal")) {                      String[] s = buff.split(" +");                    return Long.parseLong(s[1])*1024;  // 获得的buff单位是kb 故要乘以1024转成b                }            }        } catch (FileNotFoundException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        }finally{            try {                br.close();            } catch (IOException e) {                e.printStackTrace();            }        }        return 0;    }

获取正在运行的应用信息

public static List<AppInfo> getRunningAppInfos(Context context) {        List<AppInfo> runningAppInfos = new ArrayList<AppInfo>();        ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);        List<RunningAppProcessInfo> infos =am.getRunningAppProcesses();        for (RunningAppProcessInfo runningAppProcessInfo : infos) {            String processName = runningAppProcessInfo.processName;            //获取应用占用内存信息  这个里面一共只有一个数据            android.os.Debug.MemoryInfo[]  mem = am.getProcessMemoryInfo(new int[]{runningAppProcessInfo.pid});//          Log.e("------>", mem[0]+"----");            // 占用的内存            int memorySize = mem[0].getTotalPrivateDirty() * 1024;  //单位kb 需乘以1024            PackageManager pm = context.getPackageManager();            try {                ApplicationInfo appInfo = pm.getApplicationInfo(processName,0);                String packageName = appInfo.packageName;                String appName = (String) appInfo.loadLabel(pm);                Drawable icon = appInfo.loadIcon(pm);                boolean isUserApp = (appInfo.flags&ApplicationInfo.FLAG_SYSTEM)==0?true:false;                AppInfo info = new AppInfo(appName, packageName, icon, isUserApp, memorySize);//              Log.e("-------->", "appName:"+appName+"packageName:"+packageName+"memorySize:"+memorySize);                runningAppInfos.add(info);            } catch (NameNotFoundException e) {                e.printStackTrace();            }        }        return runningAppInfos;    }

判断服务是否在后台运行

/**     * 判断服务是否在后台运行     * @param context     * @param serviceName     * @return     */    public static boolean isRunning(Context context, String serviceName) {        ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);        List<RunningServiceInfo> infos = activityManager.getRunningServices(100); // 获取最多100条运行的服务        for (RunningServiceInfo runningServiceInfo : infos) {            String currentService = runningServiceInfo.service.getClassName();            if (serviceName.equals(currentService)) {       //存在当前service                return true;            }//          System.out.println(runningServiceInfo.service.getClassName());        }        return false;    }

AppInfo类

package com.yu.bean;import android.R.drawable;import android.graphics.drawable.Drawable;public class AppInfo {    /**     * 应用名字     */    private String appName;    /**     * 应用包名     */    private String packageName;    /**     * 包内的className     */    private String className;    /**     * 应用大小     */    private String appSize;    /**     * 应用图标     */    private Drawable icon;    /**     * 应用存放位置     */    private String location;    /**     * 文件目录     */    private String sourceDir;    /**     * 是否为用户应用 是则为true     */    private boolean isUserApp;    /**     * 占用内存大小     */    private int memorySize;    /**     * 是否选中     */    private boolean isChecked;    public AppInfo(String appName, String packageName, String className,            String appSize, Drawable icon, String location, String sourceDir,            boolean isUserApp) {        super();        this.appName = appName;        this.packageName = packageName;        this.className = className;        this.appSize = appSize;        this.icon = icon;        this.location = location;        this.sourceDir = sourceDir;        this.isUserApp = isUserApp;    }    public AppInfo(String appName, String packageName, Drawable icon,            boolean isUserApp, int memorySize) {        super();        this.appName = appName;        this.packageName = packageName;        this.icon = icon;        this.isUserApp = isUserApp;        this.memorySize = memorySize;    }    public boolean isChecked() {        return isChecked;    }    public void setChecked(boolean isChecked) {        this.isChecked = isChecked;    }    public int getMemorySize() {        return memorySize;    }    public void setMemorySize(int memorySize) {        this.memorySize = memorySize;    }    public String getAppName() {        return appName;    }    public void setAppName(String appName) {        this.appName = appName;    }    public String getPackageName() {        return packageName;    }    public void setPackageName(String packageName) {        this.packageName = packageName;    }    public String getClassName() {        return className;    }    public void setClassName(String className) {        this.className = className;    }    public String getAppSize() {        return appSize;    }    public void setAppSize(String appSize) {        this.appSize = appSize;    }    public Drawable getIcon() {        return icon;    }    public void setIcon(Drawable icon) {        this.icon = icon;    }    public String getLocation() {        return location;    }    public void setLocation(String location) {        this.location = location;    }    public String getSourceDir() {        return sourceDir;    }    public void setSourceDir(String sourceDir) {        this.sourceDir = sourceDir;    }    public boolean isUserApp() {        return isUserApp;    }    public void setUserApp(boolean isUserApp) {        this.isUserApp = isUserApp;    }    @Override    public String toString() {        return "AppInfo [appName=" + appName + ", packageName=" + packageName                + ", className=" + className + ", appSize=" + appSize                + ", icon=" + icon + ", location=" + location + ", sourceDir="                + sourceDir + ", isUserApp=" + isUserApp + "]";    }}