/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF 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 trailers; import java.io.IOException; import java.io.PrintWriter; import java.util.HashMap; import java.util.Map; import java.util.function.Supplier; import jakarta.servlet.ServletException; import jakarta.servlet.http.HttpServlet; import jakarta.servlet.http.HttpServletRequest; import jakarta.servlet.http.HttpServletResponse; /** * This example writes some trailer fields to the HTTP response. */ public class ResponseTrailers extends HttpServlet { private static final long serialVersionUID = 1L; private static final Supplier> TRAILER_FIELD_SUPPLIER = new TrailerFieldSupplier(); @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { resp.setTrailerFields(TRAILER_FIELD_SUPPLIER); resp.setContentType("text/plain"); resp.setCharacterEncoding("UTF-8"); PrintWriter pw = resp.getWriter(); pw.print("This response should include trailer fields."); } private static class TrailerFieldSupplier implements Supplier> { private static final Map trailerFields = new HashMap<>(); static { trailerFields.put("x-trailer-1", "Trailer value one"); trailerFields.put("x-trailer-2", "Trailer value two"); } @Override public Map get() { return trailerFields; } } }