Java tutorial
/** * Copyright 2012 Universitat Pompeu Fabra. * * 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 org.onexus.data.manager.internal.ws; import org.apache.commons.io.IOUtils; import org.onexus.data.api.IDataManager; import org.onexus.data.api.IDataStreams; import org.onexus.resource.api.IResourceManager; import org.onexus.resource.api.ORI; import org.onexus.resource.api.Project; import org.onexus.resource.api.session.LoginContext; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; public class DsServlet extends HttpServlet { private IResourceManager resourceManager; private IDataManager dataManager; @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { response(req, resp); } @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { response(req, resp); } public void response(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { HttpSession session = req.getSession(); if (session != null && LoginContext.get(session.getId()) != null) { LoginContext ctx = LoginContext.get(session.getId()); LoginContext.set(ctx, null); } else { LoginContext.set(LoginContext.ANONYMOUS_CONTEXT, null); } ORI dataResource = requestToORI(req); if (dataResource != null) { try { IDataStreams streams = dataManager.load(dataResource); // Minimum Response header information (size and MIME type) long size = dataManager.size(dataResource); resp.setContentLength((int) size); resp.setContentType(getServletContext().getMimeType(dataResource.getPath())); OutputStream out = resp.getOutputStream(); for (InputStream in : streams) { IOUtils.copy(in, out); in.close(); } out.close(); } catch (SecurityException e) { resp.sendError(HttpServletResponse.SC_FORBIDDEN, e.getMessage()); } catch (Exception e) { resp.sendError(HttpServletResponse.SC_NOT_FOUND, e.getMessage()); } } else { resp.sendError(HttpServletResponse.SC_NOT_FOUND); } } public IResourceManager getResourceManager() { return resourceManager; } public void setResourceManager(IResourceManager resourceManager) { this.resourceManager = resourceManager; } public IDataManager getDataManager() { return dataManager; } public void setDataManager(IDataManager dataManager) { this.dataManager = dataManager; } private ORI requestToORI(HttpServletRequest req) { LoginContext ctx = LoginContext.get(); try { LoginContext.set(LoginContext.SERVICE_CONTEXT, null); String uri = req.getRequestURI(); String servletPath = req.getServletPath(); if (uri.length() == servletPath.length()) { return null; } String projectNameAndResource = uri.substring(servletPath.length() + 1); String projectUrl = null; String projectName = null; for (Project project : resourceManager.getProjects()) { projectName = project.getName(); if (projectNameAndResource.startsWith(projectName)) { if (projectNameAndResource.charAt(projectName.length()) != '/') { continue; } projectUrl = project.getURL(); break; } } if (projectUrl == null) { return null; } String resourcePath = projectNameAndResource.replaceFirst(projectName, ""); return new ORI(projectUrl, resourcePath); } finally { LoginContext.set(ctx, null); } } }