001/* 002 * Copyright 2002-2012 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.web.context.support; 018 019import java.io.IOException; 020import javax.servlet.ServletException; 021import javax.servlet.http.HttpServlet; 022import javax.servlet.http.HttpServletRequest; 023import javax.servlet.http.HttpServletResponse; 024 025import org.springframework.context.i18n.LocaleContextHolder; 026import org.springframework.util.StringUtils; 027import org.springframework.web.HttpRequestHandler; 028import org.springframework.web.HttpRequestMethodNotSupportedException; 029import org.springframework.web.context.WebApplicationContext; 030 031/** 032 * Simple HttpServlet that delegates to an {@link HttpRequestHandler} bean defined 033 * in Spring's root web application context. The target bean name must match the 034 * HttpRequestHandlerServlet servlet-name as defined in {@code web.xml}. 035 * 036 * <p>This can for example be used to expose a single Spring remote exporter, 037 * such as {@link org.springframework.remoting.httpinvoker.HttpInvokerServiceExporter} 038 * or {@link org.springframework.remoting.caucho.HessianServiceExporter}, 039 * per HttpRequestHandlerServlet definition. This is a minimal alternative 040 * to defining remote exporters as beans in a DispatcherServlet context 041 * (with advanced mapping and interception facilities being available there). 042 * 043 * @author Juergen Hoeller 044 * @since 2.0 045 * @see org.springframework.web.HttpRequestHandler 046 * @see org.springframework.web.servlet.DispatcherServlet 047 */ 048@SuppressWarnings("serial") 049public class HttpRequestHandlerServlet extends HttpServlet { 050 051 private HttpRequestHandler target; 052 053 054 @Override 055 public void init() throws ServletException { 056 WebApplicationContext wac = WebApplicationContextUtils.getRequiredWebApplicationContext(getServletContext()); 057 this.target = wac.getBean(getServletName(), HttpRequestHandler.class); 058 } 059 060 061 @Override 062 protected void service(HttpServletRequest request, HttpServletResponse response) 063 throws ServletException, IOException { 064 065 LocaleContextHolder.setLocale(request.getLocale()); 066 try { 067 this.target.handleRequest(request, response); 068 } 069 catch (HttpRequestMethodNotSupportedException ex) { 070 String[] supportedMethods = ex.getSupportedMethods(); 071 if (supportedMethods != null) { 072 response.setHeader("Allow", StringUtils.arrayToDelimitedString(supportedMethods, ", ")); 073 } 074 response.sendError(HttpServletResponse.SC_METHOD_NOT_ALLOWED, ex.getMessage()); 075 } 076 finally { 077 LocaleContextHolder.resetLocaleContext(); 078 } 079 } 080 081}