How to get CPU usage statistics on Android?

Question

I want to get the overall CPU usage on Android, similar to what Windows' Task Manager does. I can parse the output of the top program included in Android, but if there is a API call that does the same thing, it would be better.

Any pointers?

Answer 1

ATTENTION: This answer is old and does NOT work on newer versions of Android due to enhanced security mechanisms.

For complete CPU usage (not for each process) you can use:

    /**  *   * @return integer Array with 4 elements: user, system, idle and other cpu  *         usage in percentage.  */ private int[] getCpuUsageStatistic() {      String tempString = executeTop();      tempString = tempString.replaceAll(",", "");     tempString = tempString.replaceAll("User", "");     tempString = tempString.replaceAll("System", "");     tempString = tempString.replaceAll("IOW", "");     tempString = tempString.replaceAll("IRQ", "");     tempString = tempString.replaceAll("%", "");     for (int i = 0; i < 10; i++) {         tempString = tempString.replaceAll("  ", " ");     }     tempString = tempString.trim();     String[] myString = tempString.split(" ");     int[] cpuUsageAsInt = new int[myString.length];     for (int i = 0; i < myString.length; i++) {         myString[i] = myString[i].trim();         cpuUsageAsInt[i] = Integer.parseInt(myString[i]);     }     return cpuUsageAsInt; }  private String executeTop() {     java.lang.Process p = null;     BufferedReader in = null;     String returnString = null;     try {         p = Runtime.getRuntime().exec("top -n 1");         in = new BufferedReader(new InputStreamReader(p.getInputStream()));         while (returnString == null || returnString.contentEquals("")) {             returnString = in.readLine();         }     } catch (IOException e) {         Log.e("executeTop", "error in getting first line of top");         e.printStackTrace();     } finally {         try {             in.close();             p.destroy();         } catch (IOException e) {             Log.e("executeTop",                     "error in closing and destroying top process");             e.printStackTrace();         }     }     return returnString; } 

Have fun with it :)