读取http流时CPU达到700％

Question

我正在使用Pushlet进行心跳，在请求时CPU达到700％。 我使用jstack转储线程信息。（对于使用jdk1.5运行的服务不使用选项[-l]），所有具有高cpu的线程在读取http流时在doPost中被阻止。 线程的一个堆栈信息如下：

Thread 30777: (state = IN_JAVA)
 - sun.nio.cs.StreamDecoder$CharsetSD.readBytes() @bci=23, line=401 (Compiled frame ;information may be imprecise)
 - sun.nio.cs.StreamDecoder$CharsetSD.implRead(char[], int, int) @bci=112, line=453 (Compiled frame)
 - sun.nio.cs.StreamDecoder.read(char[], int, int) @bci=180, line=183 (Compiled frame)
 - sun.nio.cs.StreamDecoder.read0() @bci=34, line=132 (Compiled frame)
 - nl.justobjects.pushlet.servlet.Pushlet.doPost(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse) @bci=15, line=117 (Interpreted frame)
 - javax.servlet.http.HttpServlet.service(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse) @bci=139, line=710 (Interpreted frame)
 - javax.servlet.http.HttpServlet.service(javax.servlet.ServletRequest, javax.servlet.ServletResponse) @bci=30, line=803 (Interpreted frame)

请帮助检查为什么在读取流时花费如此多的CPU时间，以何种方式可以检查此问题。

Pushlet.java的代码

    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        Event event = null;
        try {
            // Create Event by parsing XML from input stream.
[line 117]  event = EventParser.parse(new InputStreamReader(request.getInputStream()));
            // Always must have an event type
            if (event.getEventType() == null) {
                Log.warn("Pushlet.doPost(): bad request, no event specified");
                response.sendError(HttpServletResponse.SC_BAD_REQUEST, "No eventType specified");
                return;
            }
        } catch (Throwable t) {
            // Error creating event
            Log.warn("Pushlet:  Error creating event in doPost(): ", t);
            response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
            return;
        }
        // Handle parsed request
        doRequest(event, request, response);
    }