3 ways in creating custom error pages

1. web.xml

The standard webapp configuration file located in <webapp>/WEB-INF/web.xml can be used to map errors to specific URLs with the <error-page> element. This element creates a mapping between the error-code or exception typ to the location of a resource in the web application.

• error-code - integer value
• exception-type - fully qualified class name of a Java Exception type
• location - location of the resource in webapp relative to the root of the web application. Value should start with "/".

Error code example:

Exception example:

2. context file located in <jetty.home>/contexts/?.xml (any filename as long as its extension is xml)

   A basic context xml configured the class ErrorHandler to map error pages by code, exception, and range.

   There are two ways to define the error pages:
   a. WebApp context
      The error handling must derived from the class ErrorPageErroHandler.

   b. Non-webapp context
      The error handling can be derived from class ErrorHandler.

3) New class extends ErrorHandler
Here are the methods that you need to override:

• public void handle(String target, HttpServletRequest request, HttpServletResponse response, int dispatch) throws IOException
  Optional to override:
• void handleErrorPage(HttpServletRequest request, Writer writer, int code, String message) throws IOException
• void writeErrorPage(HttpServletRequest request, Writer writer, int code, String message, boolean showStacks) throws IOException
• void writeErrorPageHead(HttpServletRequest request, Writer writer, int code, String message) throws IOException
• void writeErrorPageBody(HttpServletRequest request, Writer writer, int code, String message, boolean showStacks) throws IOException
• void writeErrorPageMessage(HttpServletRequest request, Writer writer, int code, String message,String uri) throws IOException
• void writeErrorPageStacks(HttpServletRequest request, Writer writer) throws IOException