XD-401 Post data to http endpoint

Added command line option "post http" with "--target" and "--data" options
Added support to output request/response/error as handled in rest-shell
Added better error handling

Author: Ilayaperumal Gopinathan

spring-xd-shell/src/main/java/org/springframework/xd/shell/command/HttpCommands.java

@@ -0,0 +1,148 @@
+/*
+ * Copyright 2013 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.xd.shell.command;
+
+import java.io.IOException;
+import java.net.URI;
+import java.util.List;
+import java.util.Map;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.http.client.ClientHttpResponse;
+import org.springframework.shell.core.CommandMarker;
+import org.springframework.shell.core.annotation.CliAvailabilityIndicator;
+import org.springframework.shell.core.annotation.CliCommand;
+import org.springframework.shell.core.annotation.CliOption;
+import org.springframework.shell.support.util.OsUtils;
+import org.springframework.stereotype.Component;
+import org.springframework.web.client.ResourceAccessException;
+import org.springframework.web.client.ResponseErrorHandler;
+import org.springframework.web.client.RestTemplate;
+import org.springframework.xd.shell.XDShell;
+
+/**
+ * Http commands.
+ * 
+ * @author Jon Brisbin
+ * @author Ilayaperumal Gopinathan
+ */
+
+@Component
+public class HttpCommands implements CommandMarker {
+
+	private static final String POST_HTTPSOURCE = "post httpsource";
+	
+	@Autowired
+	private XDShell xdShell;
+
+	@CliAvailabilityIndicator({ POST_HTTPSOURCE })
+	public boolean available() {
+		return xdShell.getSpringXDOperations() != null;
+	}
+
+	@CliCommand(value = { POST_HTTPSOURCE }, help = "POST data to http endpoint")
+	public String postHttp(
+			@CliOption(mandatory = true, key = "target") String target,
+			@CliOption(mandatory = true, key = "data") String data) {
+		final StringBuilder buffer = new StringBuilder();
+		URI requestURI = URI.create(target);
+		RestTemplate restTemplate = new RestTemplate();
+		try {
+			restTemplate.setErrorHandler(new ResponseErrorHandler() {
+
+				@Override
+				public boolean hasError(ClientHttpResponse response)
+						throws IOException {
+					HttpStatus status = response.getStatusCode();
+					return (status == HttpStatus.BAD_GATEWAY
+							|| status == HttpStatus.GATEWAY_TIMEOUT || status == HttpStatus.INTERNAL_SERVER_ERROR);
+				}
+
+				@Override
+				public void handleError(ClientHttpResponse response)
+						throws IOException {
+					outputError(response.getStatusCode(), buffer);
+				}
+			});
+			outputRequest("POST", requestURI, data, buffer);
+			ResponseEntity<String> response = restTemplate.postForEntity(
+					requestURI, data, String.class);
+			outputResponse(response, buffer);
+			String status = (response.getStatusCode().equals(HttpStatus.OK) ? "Success"
+					: "Error");
+			return String.format(buffer.toString() + status
+					+ " sending data '%s' to target '%s'", data, target);
+		} 
+		catch (ResourceAccessException e) {
+			return String.format(buffer.toString()
+					+ "Failed to access http endpoint %s", target);
+		} 
+		catch (Exception e) {
+			return String.format(buffer.toString()
+					+ "Failed to send data to http endpoint %s", target);
+		}
+	}
+	
+	private void outputRequest(String method, URI requestUri,
+			String requestData, StringBuilder buffer) {
+		buffer.append("> ")
+			  .append(method)
+			  .append(" ")
+			  .append(requestUri.toString())
+			  .append(" ")
+			  .append(requestData)
+			  .append(OsUtils.LINE_SEPARATOR);
+	}
+
+	private void outputResponse(ResponseEntity<String> response,
+			StringBuilder buffer) {
+		buffer.append("> ")
+		      .append(response.getStatusCode().value())
+		      .append(" ")
+		      .append(response.getStatusCode().name())
+			  .append(OsUtils.LINE_SEPARATOR);
+		for (Map.Entry<String, List<String>> entry : response.getHeaders()
+				.entrySet()) {
+			buffer.append("> ").append(entry.getKey()).append(": ");
+			boolean first = true;
+			for (String s : entry.getValue()) {
+				if (!first) {
+					buffer.append(",");
+				} else {
+					first = false;
+				}
+				buffer.append(s);
+			}
+			buffer.append(OsUtils.LINE_SEPARATOR);
+		}
+		buffer.append("> ").append(OsUtils.LINE_SEPARATOR);
+		if (null != response.getBody()) {
+			buffer.append(response.getBody());
+		}
+	}
+
+	private void outputError(HttpStatus status, StringBuilder buffer) {
+		buffer.append("> ")
+		      .append(status.value())
+		      .append(" ")
+			  .append(status.name())
+			  .append(OsUtils.LINE_SEPARATOR);
+	}
+
+}