title: Why CPU cost so many time executes getNextJarEntry method?
body: <p>one of my servers's http response is very slow, it average costs 20000ms-30000ms when the response return. but another servers only cost hundreds of millisecond. the application's source code is the same.</p>
  
  <p>I use <code>visualvm</code> trying to find out the reason, and I find that the method <code>java.util.jar.JarInputStream.getNextJarEntry()</code> cost 99% time during the proceduce: </p>
  
  <p><img src="https://i.stack.imgur.com/21njG.png" alt="time cost"></p>
  
  <p>Why this situation happens, or How can I find more details about this situatiion?</p>