Java tutorial
/******************************************************************************* * Copyright (c) 2016 IBM Corp. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. *******************************************************************************/ package com.ibm.ws.lars.rest; import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.ws.rs.core.MediaType; import com.fasterxml.jackson.core.JsonFactory; import com.fasterxml.jackson.core.JsonGenerator; import com.fasterxml.jackson.core.util.DefaultPrettyPrinter; /** * Servlet to gracefully handle servlet and other 500 errors which are propagated to the web * container. * * Note: Exceptions which are propagated to JAX-RS will be handled by RepositoryExceptionMapper * before they reach the web container. */ @SuppressWarnings("serial") @WebServlet("/error") public class ErrorHandler extends HttpServlet { @Override protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setStatus(500); response.setContentType(MediaType.APPLICATION_JSON); PrintWriter printWriter = response.getWriter(); JsonGenerator frontPageJsonGenerator = new JsonFactory().createGenerator(printWriter); frontPageJsonGenerator.setPrettyPrinter(new DefaultPrettyPrinter()); frontPageJsonGenerator.writeStartObject(); frontPageJsonGenerator.writeStringField("message", "Internal server error, please contact the server administrator"); frontPageJsonGenerator.writeNumberField("statusCode", response.getStatus()); frontPageJsonGenerator.writeEndObject(); frontPageJsonGenerator.flush(); frontPageJsonGenerator.close(); } }