java.io.BufferedReader.readLine() consuming 99% CPU Why?

Question

In this code i am reading a value from stream. But readline() method is taking more CPU.Can you help me why is this so and give me suggession to minimize CPU usage.

    HttpURLConnection request = (HttpURLConnection) url.openConnection();
    request.setRequestMethod("POST");
    request.setRequestProperty("Content-Length", "0");
    request.setUseCaches(false);

    InputStreamReader in = new InputStreamReader((InputStream) request.getContent());
    BufferedReader buff = new BufferedReader(in);  

    while(line = buff.readLine() != null) {
   System.out.print("hello");
    }

from when i start my application and it consume CPU 99% until i close my application — Yogesh, Jun 26 '13 at 11:43
@johnchen902 If you have a gross performance like this, `jstack` (or more likely `ctrl-break` or whatever it happens to be on your platform) is typically sufficient. — Tom Hawtin - tackline, Jun 26 '13 at 13:31
@Tom Hawtin... can you give some idea about jstack? how can i use it ? — Yogesh, Jun 27 '13 at 06:50
@Yogesh Run `jps` to find the process id. Then just run `jstack` with that process id as an argument. — Tom Hawtin - tackline, Jun 28 '13 at 02:36

score 1 · Accepted Answer · answered Jun 26 '13 at 11:54

1

You should be attaching the BufferedReader to the input stream of the request, but I find it hard to believe the statement in your title.

answered Jun 26 '13 at 11:54

user207421

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Buhb · Answer 2 · 2013-06-26T12:50:48.823

1

I'm pretty sure the print statement is the reason for the high cpu load. What happens if you remove it?

edited Jun 26 '13 at 12:50

answered Jun 26 '13 at 12:44

Buhb

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java.io.BufferedReader.readLine() consuming 99% CPU Why?

2 Answers2