how to find memory leaks in java web application

Recently wrote a database program in Java, found that after a period of time after running a memory overflow. Want to use memory monitoring tool to see where the memory leaks, and then surf the internet and see the Jmap tools.Jmap ToolsJmap prints out all the ' objects ' in

In general, there are two cases of memory leaks, in the case of a C + + language in which memory allocated in the heap is not freed, and all of its access to the memory is removed (for example, a pointer re-assignment). This situation is like, occupying the land, others have not been able to quote, and did not release

When you move from cc++ to a language with garbage collection, the programmer's work becomes easier because you run out of objects and they are automatically recycled, but do Java programmers really need to think about memory leaks? actually otherwise1. For example-see if you can find a memory leakImport Java.util.Arra

1. What is a memory leakWhen some objects are no longer used by the application, but are still referenced, the garbage collector cannot be freed (remove)2. Causes of memory leaksLong-life-cycle objects that hold references to short-life-cycle objects are likely to have a memory leak (old-age reference generation)2.1 Wh

The answer is yes, but I can't answer the interviewer's question with this sentence.Analysis: Java is a garbage collection mechanism, in such a context, memory leaks are also known as "unconscious object hold." If an object reference is left unconscious, the garbage collector not only handles the object, but also does not handle other objects referenced by the ob

memory leaks caused by the Java Finalize MethodPosted:mon, Mar 2013 Java Memory Dump After the memory dump, a lot of memory (>5g) is Java.lang.ref.Finalizer hold (see Figure 1). And th

often used in the development process to replicate objects using the Clone () method. For example, when a function parameter type is a custom class, it is a reference pass instead of a value pass. Here is a small example: Public class A implements Cloneable { Public String name; Public Object Clone () { A o = null; try { o = (A) super.clone (); } catch (Clonenotsupportedexception e) { E.printstacktrace (); } return o; } } A a1=new A ();

A Java memory leak is divided into two main areas:(1) The space requested in the heap has not been released.(2) The object is no longer in use, but still exists in memoryThe following concentration conditions can cause a memory leak(1) Static collection using HashMap and vectors, the life cycle of the static container is consistent with the program, then the cont

That's because your Web application has a memory leak.A Common issue is "PermGen" memory leaks. They happen because the Classloader (and the Class objects it loaded) cannot be recycledUnless some requirements is met (*). They is stored in the permanent heap generation by the

-xms and-xmx are an option for Java commands to set the available memory size for your application startup and the amount of memory available at run time. XMX is an option in Java to set the maximum amount of memory your

Bad memory:-listeners in Java Web Applications (1) and-Java Web listeners A listener is an object that is used to listen for and process events or state changes on other objects. When the Monitored Objects occur, they take corresponding actions immediately.The listener in

exceptions, reducing unnecessary object creation while avoiding memory leaks. Now take a real example to analyze the troubleshooting of memory footprint. The top command found that a Java process with a PID of 9004 had been consuming a higher memory release (24.7%) and a h

Server CPU, memory normal, some sites can not open, application pool recycling is normal, how to solve? Questions: Server \iis and ASP issues I would like to ask next you ' site recently a few times a day to play not open very slowly ' only show tile title other No, the site is ASP, foreground-generated HTML, today saw the W3WP.exe occupancy up to 280M, Generally only about 170M of IIS management in the a

Java web session simple application, Java web session Java sessions are divided into Cookie and HttpSession.Cookie technology: session data is stored on the browser client.Session technology: Session data is stored on the server.I

processing.3 , using HttpServletResponse to redirect the source codePackage com.servlet;Import java.io.IOException;Import javax.servlet.ServletException;Import Javax.servlet.http.HttpServlet;Import Javax.servlet.http.HttpServletRequest;Importjavax.servlet.http.HttpServletResponse;/*** REDIRECT via HttpServletResponse* @author Fan Fangming*/public class Responsededirect Extendshttpservlet {Privatestatic final Long serialversionuid = -7412891131635994698l;Publicvoid doget (httpservletrequest requ

As described in the summary, the frequent need to deploy the program to the test machine at the time of the tune-up, it is inconvenient to debug. The previous practice is to print information in the program to track, but this method is very limited, because often can not be located in the problem at once, need to constantly modify the program to print the statement, constantly restart the application, which takes a lot of time and effort. Therefore, i

Filter, which is very powerful, is one of the most important technologies in the Servlet, and Web application developers use the filter technology to manage all Web resources on the Web server: JSP, Servlet, Static image files or static HTML files, etc. to intercept, so as to achieve some special functions. For exam