| /******************************************************************************* |
| * Copyright (C) 2021 the Eclipse BaSyx Authors |
| * |
| * This program and the accompanying materials are made |
| * available under the terms of the Eclipse Public License 2.0 |
| * which is available at https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| ******************************************************************************/ |
| package org.eclipse.basyx.vab.protocol.http.server; |
| |
| import java.io.IOException; |
| import java.io.PrintWriter; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import javax.servlet.ServletException; |
| import javax.servlet.http.HttpServlet; |
| import javax.servlet.http.HttpServletRequest; |
| import javax.servlet.http.HttpServletResponse; |
| |
| import org.eclipse.basyx.vab.coder.json.serialization.DefaultTypeFactory; |
| import org.eclipse.basyx.vab.coder.json.serialization.GSONTools; |
| |
| /** |
| * HTTP Servelet superclass to enable HTTP Patch |
| * @author pschorn |
| * |
| */ |
| public abstract class BasysHTTPServlet extends HttpServlet { |
| |
| |
| /** |
| * Version of serialized instances |
| */ |
| private static final long serialVersionUID = 1L; |
| |
| |
| /** |
| * Parameter map |
| */ |
| protected Map<String, String> servletParameter = new HashMap<>(); |
| |
| /** |
| * GSON instance |
| */ |
| protected GSONTools serializer = new GSONTools(new DefaultTypeFactory()); |
| |
| |
| |
| /** |
| * Dispatch service call |
| */ |
| @Override |
| public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { |
| if (request.getMethod().equalsIgnoreCase("PATCH")){ |
| doPatch(request, response); |
| } else { |
| super.service(request, response); |
| } |
| } |
| |
| |
| /** |
| * Implement Patch request |
| */ |
| protected abstract void doPatch(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException; |
| |
| |
| /** |
| * Add a servlet parameter |
| */ |
| |
| public BasysHTTPServlet withParameter(String parameter, String value) { |
| // Add parameter |
| servletParameter.put(parameter, value); |
| |
| // Return this instance |
| return this; |
| } |
| |
| |
| /** |
| * Get init parameter of servlet |
| */ |
| @Override |
| public String getInitParameter(String name) { |
| // Check if servletParameter map contains requested parameter |
| if (servletParameter.containsKey(name)) return servletParameter.get(name); |
| |
| // Call base method |
| return super.getInitParameter(name); |
| } |
| |
| /** |
| * Send a response |
| */ |
| protected void sendResponse(Object value, PrintWriter outputStream) { |
| // Output result |
| outputStream.write(serializer.serialize(value)); |
| outputStream.flush(); |
| } |
| |
| } |
| |