Initial commit for HttpInboundGateway (INT-470).

org.springframework.integration.http/src/main/java/org/springframework/integration/http/HttpInboundGateway.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2002-2009 the original author or authors.
+ *
+ * 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.springframework.integration.http;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Enumeration;
+import java.util.List;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.springframework.integration.gateway.SimpleMessagingGateway;
+import org.springframework.integration.message.MessageBuilder;
+import org.springframework.web.HttpRequestHandler;
+
+/**
+ * @author Mark Fisher
+ * @since 1.0.2
+ */
+public class HttpInboundGateway extends SimpleMessagingGateway implements HttpRequestHandler {
+
+	public void handleRequest(HttpServletRequest request,
+			HttpServletResponse response) throws ServletException, IOException {
+
+		MessageBuilder<?> builder = MessageBuilder.withPayload(request.getParameterMap());
+		this.populateHeaders(request, builder);
+		Object result = this.sendAndReceive(builder.build());
+		if (result instanceof String) {
+			response.getWriter().print((String) result);
+			response.flushBuffer();
+		}
+		else if (result instanceof byte[]) {
+			response.getOutputStream().write((byte[]) result);
+			response.flushBuffer();
+		}
+		else {
+			throw new ServletException("invalid response type [" + result.getClass().getName() + "]"); 
+		}
+	}
+
+	private void populateHeaders(HttpServletRequest request, MessageBuilder<?> builder) {
+		Enumeration<?> headerNames = request.getHeaderNames();
+		if (headerNames != null) {
+			while (headerNames.hasMoreElements()) {
+				String headerName = (String) headerNames.nextElement();
+				Enumeration<?> headerEnum = request.getHeaders(headerName);
+				if (headerEnum != null) {
+					List<Object> headers = new ArrayList<Object>();
+					while (headerEnum.hasMoreElements()) {
+						headers.add(headerEnum.nextElement());
+					}
+					if (headers.size() == 1) {
+						builder.setHeader(headerName, headers.get(0));
+					}
+					else if (headers.size() > 1) {
+						builder.setHeader(headerName, headers);
+					}
+				}
+			}
+		}
+	}
+
+}