package com.codahale.metrics.servlets;
import com.codahale.metrics.jvm.ThreadDump;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.management.ManagementFactory;
/**
* An HTTP servlets which outputs a {@code text/plain} dump of all threads in the VM. Only responds
* to {@code GET} requests.
*/
public class ThreadDumpServlet extends HttpServlet {
private static final long serialVersionUID = -2690343532336103046L;
private static final String CONTENT_TYPE = "text/plain";
private transient ThreadDump threadDump;
@Override
public void init() throws ServletException {
this.threadDump = new ThreadDump(ManagementFactory.getThreadMXBean());
}
@Override
protected void doGet(HttpServletRequest req,
HttpServletResponse resp) throws ServletException, IOException {
resp.setStatus(HttpServletResponse.SC_OK);
resp.setContentType(CONTENT_TYPE);
resp.setHeader("Cache-Control", "must-revalidate,no-cache,no-store");
final OutputStream output = resp.getOutputStream();
try {
threadDump.dump(output);
} finally {
output.close();
}
}
}