android开发获取手机内存使用情况

public Object getPenter() {
String dir = "/proc/meminfo";
try {
FileReader fr = new FileReader(dir);
BufferedReader br = new BufferedReader(fr, 2048);
String memoryLine = br.readLine();
String subMemoryLine = memoryLine.substring(memoryLine.indexOf("MemTotal:"));
br.close();
long totalMemorySize = Integer.parseInt(subMemoryLine.replaceAll("\\D+", ""));
long availableSize = getAvailableMemory(MainActivity.this) / 1024;
int percent = (int) ((totalMemorySize - availableSize) / (float) totalMemorySize * 100);
return percent + "%";
} catch (IOException e) {
e.printStackTrace();
}
return "无结果";
}
private  long getAvailableMemory(Context context) {
ActivityManager.MemoryInfo mi = new ActivityManager.MemoryInfo();
getActivityManager(context).getMemoryInfo(mi);
return mi.availMem;
}
public  ActivityManager getActivityManager(Context context) {
if (mActivityManager == null) {
mActivityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
}
return mActivityManager;
}