获取手机内存\可用内存\单个APP运行内存

 /** 手机总内存 */
     private String getTotalMemory() {
         // 系统内存信息文件
         String str1 = "/proc/meminfo";
         String str2;
         String[] arrayOfString;
         long initial_memory = 0;

         try {
             FileReader localFileReader = new FileReader(str1);
             BufferedReader localBufferedReader = new BufferedReader(
                     localFileReader, 8192);
             // 读取meminfo第一行，系统总内存大小
             str2 = localBufferedReader.readLine();

             arrayOfString = str2.split("\\s+");
             for (String num : arrayOfString) {
                 Log.i(str2, num + "\t");
             }
             // 获得系统总内存，单位是KB，乘以1024转换为Byte
             initial_memory = Integer.valueOf(arrayOfString[1]).intValue() * 1024;
             localBufferedReader.close();
         } catch (IOException e) {
         }
         // Byte转换为KB或者MB，内存大小规格化
         return Formatter.formatFileSize(getBaseContext(), initial_memory);
     }

 /** 获取android当前可用内存大小 */
     private String getAvailMemory() {
         ActivityManager am = (ActivityManager) getSystemService(
              Context.ACTIVITY_SERVICE);
         MemoryInfo mi = new MemoryInfo();
         am.getMemoryInfo(mi);
         // mi.availMem; 当前系统的可用内存
         // 将获取的内存大小规格化
         return Formatter.formatFileSize(getBaseContext(), mi.availMem);
     }

 /** Android获取应用所占内存大小 */
 2 private void getRunningAppProcessInfo() {
   ActivityManager mActivityManager = (ActivityManager) getSystemService(
       Context.ACTIVITY_SERVICE);

    // 获得系统里正在运行的所有进程
    List<RunningAppProcessInfo> runningAppProcessesList = mActivityManager
         .getRunningAppProcesses();

    for (RunningAppProcessInfo runningAppProcessInfo : runningAppProcessesList) {
       // 进程ID号
       int pid = runningAppProcessInfo.pid;
       // 用户ID
       int uid = runningAppProcessInfo.uid;
       // 进程名
       String processName = runningAppProcessInfo.processName;
       // 占用的内存
       int[] pids = new int[] { pid };
       Debug.MemoryInfo[] memoryInfo = mActivityManager
              .getProcessMemoryInfo(pids);
       int memorySize = memoryInfo[0].dalvikPrivateDirty;

       Log.i(TAG, "processName=" + processName + ",pid=" + pid + ",uid="
             + uid + ",memorySize=" + memorySize + "kb");
     }
 }

 /**
   * 获取单个 app 内存限制大小
   * 返回以 M 为单位的数字，
   * 可能在不同的平台或者设备上值都不太一样
  */
  private void test01() {
    ActivityManager activityManager2 = (ActivityManager) getSystemService(
       Context.ACTIVITY_SERVICE);
    activityManager2.getMemoryClass();
  }