HTTP-CLIENT 2.0 RC1
SUN JDK 1.4.2
WIN-XP SP1 (leave me alone)
Have noticed that the use of getResponseBody() on GetMethod leaks file
handles as compared to getResponseBodyAsStream(). Bizzar but true. The
following examples are for bug/feature demonstration only. I tested
against a local Tomcat. When repeating the tests change to an available
server/page.
Try running the following and monitoring the Java process with the task
manager with the additional column "handles" selected and run over a ten
minutes period. Ater ten minutes the handle count is at 827 (on my
machine).
// Leaking handles example
public static void main(String[] args) {
while (true) {
HttpClient client = null;
GetMethod method = null;
try {
client = new HttpClient();
method = new GetMethod("http://localhost:8080";);
client.executeMethod(method);
int httpStatus = method.getStatusCode();
String responseBody = new String(method.getResponseBody());
System.out.println("status: " + httpStatus);
}
catch (Throwable t) {}
finally {
try {
method.releaseConnection();
}
catch (Throwable t) {}
}
try {
Thread.sleep(100); // gives time for garbage etc.
}
catch (InterruptedException ie) {}
}
}
In comparison, then try the following code using getResponseAsStream().
After ten minutes it uses just 339 handles.
// No leaking handles example
public static void main(String[] args) {
while (true) {
HttpClient client = null;
GetMethod method = null;
try {
client = new HttpClient();
method = new GetMethod("http://localhost:8080";);
client.executeMethod(method);
int httpStatus = method.getStatusCode();
InputStream is = method.getResponseBodyAsStream();
byte[] buffer = new byte[16000];
int len = is.read(buffer);
byte[] body = new byte[len];
System.arraycopy(buffer, 0, body, 0, len);
String responseBody = new String(body);
System.out.println("status: " + httpStatus);
}
catch (Throwable t) {}
finally {
try {
method.releaseConnection();
}
catch (Throwable t) {}
}
try {
Thread.sleep(100); // gives time for garbage etc.
}
catch (InterruptedException ie) {}
}
}
This would 'appear' to be a serious bug. Ten minutes and ~500 handles lost,
so what after a day...
Have had a quick debug step thru of getResponseBody() and it does appear to
not execute any of clean up code, that happens in the second example.
Obviously I have a workaround, but feedback on whether other have the same
result (on Solaris would be interesting).
Ta.
________________________________________________________________
David Wade Senior Consultant
Optimation NZ Ltd Phone :+64-9-3097918
L4, Optimation House DDI :+64-9-3075561
43 College Hill Rd Mobile:it doesn't work.
PO Box 106-104 mailto:[EMAIL PROTECTED]
Auckland, New Zealand Web :http://www.optimation.co.nz
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