001/* 002 * Copyright 2002-2017 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; 020 021import javax.servlet.ServletException; 022import javax.servlet.http.HttpServlet; 023import javax.servlet.http.HttpServletRequest; 024import javax.servlet.http.HttpServletResponse; 025 026import org.springframework.context.support.LiveBeansView; 027import org.springframework.lang.Nullable; 028import org.springframework.util.Assert; 029 030/** 031 * Servlet variant of {@link LiveBeansView}'s MBean exposure. 032 * 033 * <p>Generates a JSON snapshot for current beans and their dependencies in 034 * all ApplicationContexts that live within the current web application. 035 * 036 * @author Juergen Hoeller 037 * @since 3.2 038 * @see org.springframework.context.support.LiveBeansView#getSnapshotAsJson() 039 */ 040@SuppressWarnings("serial") 041public class LiveBeansViewServlet extends HttpServlet { 042 043 @Nullable 044 private LiveBeansView liveBeansView; 045 046 047 @Override 048 public void init() throws ServletException { 049 this.liveBeansView = buildLiveBeansView(); 050 } 051 052 protected LiveBeansView buildLiveBeansView() { 053 return new ServletContextLiveBeansView(getServletContext()); 054 } 055 056 057 @Override 058 protected void doGet(HttpServletRequest request, HttpServletResponse response) 059 throws ServletException, IOException { 060 061 Assert.state(this.liveBeansView != null, "No LiveBeansView available"); 062 String content = this.liveBeansView.getSnapshotAsJson(); 063 response.setContentType("application/json"); 064 response.setContentLength(content.length()); 065 response.getWriter().write(content); 066 } 067 068}