How To Call Error Page In Servlet
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Exception Handling In Servlet Example
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Exception Handling In Servlet And Jsp
Stack Overflow is a community of 4.7 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up How to redirect to error page in servlet? up web.xml error-page exception-type vote 2 down vote favorite I am writing the servlet , in case of exception I am redirecting to my customized error page for that i have done like this. In web.xml
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Web.xml Error-page Not Working
Error Handling Example TutorialJuly 14, 2016 by Pankaj 13 Comments Today how can an exception caught in your servlet be logged we will look into Servlet Exception and Error Handling. Sometime back I wrote a post about Exception
Servlet Filter Exception Handling
Handling in Java but when it comes to web application, we need more than normal exception handling in java.Servlet ExceptionIf you notice, doGet() and doPost() methods throw http://stackoverflow.com/questions/26838036/how-to-redirect-to-error-page-in-servlet javax.servlet.ServletException and IOException, let's see what happens when we throw these exception from our application. I will write a simple servlet that will throw the ServletException. package com.journaldev.servlet.exception; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; @WebServlet("/MyExceptionServlet") public class MyExceptionServlet extends HttpServlet { private static final long serialVersionUID = 1L; http://www.journaldev.com/1973/servlet-exception-and-error-handling-example-tutorial protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { throw new ServletException("GET method is not supported."); } } Now when we invoke this servlet through browser with GET method, we get response like below image.Since browser understand only HTML, when our application throw exception, servlet container processes the exception and generate a HTML response. This logic is specific to servlet container. I am using tomcat and getting this error page. If you will use some other servers like JBoss or Glassfish, you might get different error HTML response.The problem with this response is that it's of no value to user. Also it's showing our application classes and server details to user that makes no sense to user and it's not good from security point of view.Servlet ErrorI am sure you must have seen 404 error when you are trying to hit a URL that doesn't exists. Let's see how our servlet container responds to 404 error. If we send request for
versioned snapshots for indefinite support ... scalability guidance for your apps and Ajax/Comet projects ... development services http://www.eclipse.org/jetty/documentation/9.3.x/custom-error-pages.html for sponsored feature development Creating Custom Error PagesDefining error pages in web.xmlConfiguring error pages context filesCustom ErrorHandler classServer level 404 errorThe following http://docstore.mik.ua/orelly/java-ent/servlet/ch05_07.htm sections describe several ways to create custom error pages in Jetty.Defining error pages in web.xmlYou can use the standard webapp configuration error page file located in webapp/WEB-INF/web.xml to map errors to specific URLs with the error-page element. This element creates a mapping between the error-code or exception-type to the location of a resource in the web application.error-code - an integer valueexception-type - a fully qualified class name exception handling in of a Java Exception typelocation - location of the resource in the webapp relative to the root of the web application. Value should start with /.Error code example:
resources, and (gasp!) actual bugs. The point here is that a servlet has to be prepared for problems, both expected and unexpected. There are two points of concern when things go wrong: Limiting damage to the server Properly informing the client Because servlets are written in Java, the potential damage they can cause to their server is greatly minimized. A server can safely embed servlets (even within its process), just as a web browser can safely embed downloaded applets. This safety is built on Java's security features, including the use of protected memory, exception handling, and security managers. Java's memory protection guarantees that servlets cannot accidentally (or intentionally) access the server's internals. Java's exception handling lets a server catch every exception raised by a servlet. Even if a servlet accidentally divides by zero or calls a method on a null object, the server can continue to function. Java's security manager mechanism provides a way for servers to place untrusted servlets in a sandbox, limiting their abilities and keeping them from intentionally causing problems. You should be aware that trusted servlets executing outside a security manager's sandbox are given abilities that could potentially cause damage to the server. For example, a servlet can overwrite the server's file space or even call System.exit(). It is also true that a trusted servlet should never cause damage except by accident, and it's hard to accidentally call System.exit(). Still, if it's a concern, even trusted servlets can be (and often are) run inside a fairly lenient but sanity-checking security manager. Properly describing a problem to the client cannot be handled by Java language technology alone. There are many things to consider: How much to tell the client? Should the servlet send a generic status code error page, a prose explanation of the problem, or (in the case of a thrown exception) a detailed stack trace? What if the servlet is supposed to return nontextual content, such as an image? How to record the problem? Should it be saved to a file, written to the server log, sent to the client, or ignored? How to recover? Can the same servlet instance hand