76 lines
2.6 KiB
Java
76 lines
2.6 KiB
Java
Servlet exception handler
|
|
|
|
|
|
|
|
package com.ack.web.servlet;
|
|
|
|
import java.io.ByteArrayOutputStream;
|
|
import java.io.IOException;
|
|
import java.io.PrintWriter;
|
|
import javax.servlet.ServletException;
|
|
import javax.servlet.http.HttpServlet;
|
|
import javax.servlet.http.HttpServletRequest;
|
|
import javax.servlet.http.HttpServletResponse;
|
|
|
|
/**
|
|
* Map the location of the servlet to handle at error
|
|
* with the supplied status code
|
|
*
|
|
<web-app>
|
|
...
|
|
<error-page>
|
|
<exception-type>javax.servlet.ServletException</exception-type>
|
|
<location>/servlet/com.ack.web.servlet.ServletExceptionHandler</location>
|
|
</error-page>
|
|
</web-app>
|
|
*/
|
|
public class ServletExceptionHandler extends HttpServlet {
|
|
public void doGet( HttpServletRequest req, HttpServletResponse res )
|
|
throws ServletException, IOException {
|
|
res.setContentType( "text/html" );
|
|
PrintWriter pw = res.getWriter();
|
|
|
|
String exceptionType = getRequestAttribute( req,
|
|
"javax.servlet.error.exception_type",
|
|
"status code not supplied" );
|
|
String errorMsg = getRequestAttribute( req,
|
|
"javax.servlet.error.message",
|
|
"error msg not supplied" );
|
|
|
|
// exception attribute available as of servlet 2.3 API
|
|
Object exception = req.getAttribute( "javax.servlet.error.exception" );
|
|
|
|
pw.println( "<h1>Custom Exception Handler</h1>" );
|
|
pw.println( "<h2>Exception type: " + exceptionType + "</h1>" );
|
|
pw.println( "<h2>Exception Message: " + errorMsg + "</h1>" );
|
|
pw.println( "<p>Problem accessing: " + req.getRequestURI() + "</p>" );
|
|
|
|
// if we have the exception dump it out to the page
|
|
if( exception != null ) {
|
|
ByteArrayOutputStream bos = null;
|
|
try {
|
|
pw.println( "<p><hr noshade><p><pre>" );
|
|
bos = new ByteArrayOutputStream();
|
|
PrintWriter writer = new PrintWriter( bos, true );
|
|
( (Exception) exception ).printStackTrace( writer );
|
|
pw.println( bos.toString() );
|
|
}
|
|
finally {
|
|
pw.println( "</pre>" );
|
|
if( bos != null ) bos.close();
|
|
}
|
|
}
|
|
|
|
// output date and time of error
|
|
pw.println( "<p><hr><p>" );
|
|
pw.println( new java.util.Date( System.currentTimeMillis() ) );
|
|
}
|
|
|
|
private String getRequestAttribute( HttpServletRequest req,
|
|
String name,
|
|
String defaultValue ) {
|
|
Object value = req.getAttribute( name );
|
|
return ( value != null ) ? value.toString() : defaultValue;
|
|
}
|
|
}
|