The HTTP DELETE operation gets a message from a WebSphere® MQ queue, or retrieves a publication from a topic. The message is removed from the queue. If the publication is retained, it is not removed. A response message is sent back to the client including information about the message.

Request

>>-+-DELETE-+-- --| Path |-- --HTTP version--CRLF--------------->

   '-GET----'                                       

   .-CRLF---------------.  .-CRLF---------------.   

   V                    |  V                    |   

>----+----------------+-+----+----------------+-+--------------->

     '-general-header-'      '-request-header-'     

   .-CRLF----------------------------.   

   V                                 |   

>----+-----------------------------+-+-------------------------><

     '-| Entity-header (Request) |-'     

Path

|--/--contextRoot--/-------------------------------------------->

>--msg/--+-queue/--queueName--+-------------+-+--/--------------|

         |                    '-@--qMgrName-' |      

         '-topic/--topicName------------------'      

entity-header (Request)

|--+----------------------------------------------+-------------|

   +-standard entity-header-- --entity-value------+   

   +-x-msg-correlId - --correlation ID------------+   

   +-x-msg-msgId - --message ID-------------------+   

   +-x-msg-range-- --range------------------------+   

   +-x-msg-require-headers-- --entity header name-+   

   '-x-msg-wait - --wait time---------------------'   

Response

>>-HTTP version-- --HTTP Status-Code-- --HTTP Reason-Phrase--CRLF-->

   .-CRLF---------------.  .-CRLF----------------.   

   V                    |  V                     |   

>----+----------------+-+----+-----------------+-+-------------->

     '-general-header-'      '-response-header-'     

   .-CRLF-----------------------------.                      

   V                                  |                      

>----+------------------------------+-+--+---------------+-----><

     '-| Entity-header (Response) |-'    '-CRLF--Message-'   

entity-header (Response)

|--+-----------------------------------------+------------------|

   +-standard entity-header-- --entity-value-+   

   +-x-msg-class-- --message type------------+   

   +-x-msg-correlId-- --correlation ID-------+   

   +-x-msg-encoding-- --encoding type--------+   

   +-x-msg-expiry-- --duration---------------+   

   +-x-msg-format-- --message format---------+   

   +-x-msg-msgId-- --message ID--------------+   

   +-x-msg-persistence-- --persistence-------+   

   +-x-msg-priority-- --priority class-------+   

   +-x-msg-replyTo-- --reply-to queue--------+   

   +-x-msg-timestamp-- --HTTP-date-----------+   

   '-x-msg-usr-- --user properties-----------'   

DELETE /msg/queue/myQueue/ HTTP/1.1

Host: www.example.org

x-msg-wait: 10

x-msg-require-headers: correlID

HTTP/1.1 200 OK

Date: Wed, 2 Jan 2007 22:38:34 GMT

Server: Apache-Coyote/1.1 WMQ-HTTP/1.1 JEE-Bridge/1.1

Content-Length: 50

Content-Type: text/plain; charset=utf-8

x-msg-correlId: 1234567890

Here's my message body that will appear on the queue.

1. package com.etrip.mqttv3.http;
2. /**
3. * This sample shows how to delete a message. It has slightly enhanced function
4. * of the amqsget command in that it will print out the timestamp, expiry and
5. * persistence of the messages. The program continues until the queue is empty
6. * or a request fails. This program can potentially take in three parameters:
7. * <queueName>
8. * <host:port> <context-root (the MQ Bridge for HTTP's context-root)>
9. * defaults are: SYSTEM.DEFAULT.LOCAL.QUEUE localhost:8080 mq
10. *
11. * If there are any exceptions thrown from this program or errors returned from the server then they are
12. * printed to standard output as-is.
13. *
14. * No more messages
15. * HTTP DELETE Sample end
16. */
17. import java.io.BufferedReader;
18. import java.io.IOException;
19. import java.io.InputStreamReader;
20. import java.net.HttpURLConnection;
21. import java.net.MalformedURLException;
22. import java.net.URL;
23. /**
24. *
25. * 采用HTTP DELETE方式的订阅相关的MQTT的主题的信息
26. *
27. * @author longgangbai
28. *
29. *
30. */
31. public class HTTPDELETE
32. {
33. private static final String DEFAULT_HOST = "localhost";
34. private static final String DEFAULT_PORT = "8080";
35. private static final String DEFAULT_QUEUE = "SYSTEM.DEFAULT.LOCAL.QUEUE";
36. private static final String DEFAULT_CONTEXT_ROOT = "mq";
37. public static String newline = System.getProperty("line.separator");
38. private static final String MESSAGE_BOUNDARY = "_________________________________________________________________________________________";
39. // the maximum length of the message that we want to print to the screen
40. private static final int MAX_OUTPUT_MESSAGE_SIZE = 256;
41. private static int OK_RC = 200;
42. /**
43. * 构建订阅主题队列路径
44. *
45. * @param host
46. * @param port
47. * @param context
48. * @param queueName
49. */
50. private static String getPublishQueueURL(String host, String port,
51. String context, String queueName) {
52. StringBuffer urlString =new StringBuffer("http://");
53. if(StringUtils.isEmtry(host)){
54. host=DEFAULT_HOST;
55. }
56. if(StringUtils.isEmtry(port)){
57. port=DEFAULT_PORT;
58. }
59. urlString.append(host).append(":").append(port);
60. if(StringUtils.isEmtry(context)){
61. context=DEFAULT_CONTEXT_ROOT;
62. }
63. urlString.append("/");
64. urlString.append(context);
65. urlString.append("/msg/queue/");
66. if(StringUtils.isEmtry(queueName)){
67. queueName=DEFAULT_QUEUE;
68. }
69. urlString.append(queueName);
70. System.out.println("urlString="+urlString);
71. return urlString.toString();
72. }
73. /**
74. *  通过HTTP POST 订阅主题的具体实现
75. * @param host
76. * @param port
77. * @param context
78. * @param queueName
79. * @return
80. * @throws MalformedURLException
81. */
82. public static boolean subTopic(String host,String port,String context,String queueName ){
83. String publishURL=getPublishQueueURL(host, port, context, queueName);
84. URL url=null;
85. HttpURLConnection connection=null;
86. try {
87. url = new URL(publishURL);
88. connection= (HttpURLConnection) url.openConnection();
89. /* Build the headers */
90. // the verb first.
91. connection.setRequestMethod("DELETE");
92. // write out what headers we want back
93. // the header names are case-sensitive
94. connection.setRequestProperty("x-msg-require-headers",
95. "timestamp, expiry, persistence");
96. // Now actually send the request message. There is no content as this is a
97. // DELETE
98. connection.connect();
99. String formattedMessage = null;
100. // check the response for errors
101. int responseCode = connection.getResponseCode();
102. if (responseCode == OK_RC)
103. {
104. // Get the headers first
105. String timestamp = connection.getHeaderField("x-msg-timestamp");
106. String expiry = connection.getHeaderField("x-msg-expiry");
107. String persistence = connection.getHeaderField("x-msg-persistence");
108. // now get the message data
109. BufferedReader reader = new BufferedReader(new InputStreamReader(
110. connection.getInputStream()));
111. String line = null;
112. StringBuffer messageBuffer = new StringBuffer();
113. while ((line = reader.readLine()) != null)
114. {
115. messageBuffer.append(line);
116. }
117. String messageBody = messageBuffer.toString();
118. formattedMessage = MESSAGE_BOUNDARY + newline;
119. // Which is greater the max output message size or the message length?
120. int messageSizeToPrint = messageBody.length() > MAX_OUTPUT_MESSAGE_SIZE ? MAX_OUTPUT_MESSAGE_SIZE
121. : messageBody.length();
122. formattedMessage += messageBody.substring(0, messageSizeToPrint)
123. + newline;
124. formattedMessage += "timestamp   = " + timestamp + newline;
125. formattedMessage += "expiry      = " + expiry + newline;
126. formattedMessage += "persistence = " + persistence + newline;
127. System.out.println("formattedMessage "+formattedMessage);
128. }else{
129. String responseMessage =connection.getResponseMessage();
130. System.out.println("responsere sponseCode "+responseCode+" response request ="+responseMessage);
131. }
132. } catch (MalformedURLException e) {
133. // TODO Auto-generated catch block
134. e.printStackTrace();
135. } catch (IOException e) {
136. // TODO Auto-generated catch block
137. e.printStackTrace();
138. }finally{
139. connection.disconnect();
140. }
141. return false;
142. }
143. public static void main(String[] args) {
144. HTTPDELETE.subTopic("192.168.208.46", "8080", "mq", "java_lover");
145. }
146. }