Java tutorial
/* * Copyright (c) 2005-2010, WSO2 Inc. (http://www.wso2.org) All Rights Reserved. * * WSO2 Inc. licenses this file to you 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 org.wso2.carbon.registry.resource.servlets; import org.wso2.carbon.registry.core.RegistryConstants; import org.wso2.carbon.registry.core.exceptions.RegistryException; import org.wso2.carbon.registry.core.session.UserRegistry; import org.wso2.carbon.registry.core.Resource; import org.wso2.carbon.registry.core.Collection; import org.wso2.carbon.registry.core.utils.RegistryUtils; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.ServletException; import javax.servlet.ServletOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.PrintWriter; public class ResourceServlet extends HttpServlet { private static final Log log = LogFactory.getLog(ResourceServlet.class); protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { try { UserRegistry registry = (UserRegistry) request.getSession() .getAttribute(RegistryConstants.ROOT_REGISTRY_INSTANCE); String path = request.getParameter("path"); if (path == null) { String msg = "Could not get the resource content. Path is not specified."; log.error(msg); response.setStatus(400); return; } Resource resource = null; try { resource = registry.get(path); } catch (RegistryException e) { String msg = "Error retrieving the resource " + path + ". " + e.getMessage(); log.error(msg, e); throw e; } if (resource instanceof Collection) { String msg = "Could not get the resource content. Path " + path + " refers to a collection."; log.error(msg); response.setStatus(501); return; } response.setDateHeader("Last-Modified", resource.getLastModified().getTime()); if (resource.getMediaType() != null && resource.getMediaType().length() > 0) { response.setContentType(resource.getMediaType()); } else { response.setHeader("Content-Disposition", "attachment; filename=" + RegistryUtils.getResourceName(path)); response.setContentType("application/download"); } InputStream contentStream = resource.getContentStream(); if (contentStream != null) { try { ServletOutputStream servletOutputStream = response.getOutputStream(); byte[] contentChunk = new byte[1024]; int byteCount; while ((byteCount = contentStream.read(contentChunk)) != -1) { servletOutputStream.write(contentChunk, 0, byteCount); } response.flushBuffer(); servletOutputStream.flush(); } finally { contentStream.close(); } } else { Object content = resource.getContent(); if (content != null) { if (content instanceof byte[]) { ServletOutputStream servletOutputStream = response.getOutputStream(); servletOutputStream.write((byte[]) content); response.flushBuffer(); servletOutputStream.flush(); } else { PrintWriter writer = response.getWriter(); writer.write(content.toString()); writer.flush(); } } } resource.discard(); } catch (RegistryException e) { String msg = "Failed to get resource content. " + e.getMessage(); log.error(msg, e); response.setStatus(500); return; } } }