Java sends HTTP requests (submits form form)

http://hbiao68.iteye.com/blog/1973914

Write a servlet for test requests

Java code

2. Import java.io.IOException;
4. Import Java.io.PrintWriter;
8. Import javax.servlet.ServletException;
10. Import Javax.servlet.http.HttpServlet;
12. Import Javax.servlet.http.HttpServletRequest;
14. Import Javax.servlet.http.HttpServletResponse;
18. Public class ABC extends HttpServlet {
22. protected void doget (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException {
24. System.out.println ("doget");
26. This.dopost (request, response);
28. }
32. protected void DoPost (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException {
34. System.out.println ("DoPost");
36. System.out.println ("AAA:" +request.getparameter ("aaa"));
38. System.out.println ("param1:" +request.getparameter ("param1"));
42. System.out.println (Request.getheader ("AVC"));
46. PrintWriter pw = Response.getwriter ();
48. Pw.write (Request.getparameter ("param1"));
50. Pw.flush ();
52. Pw.close ();
54. }
58. }

Web. XML configuration file

XML code

2. <servlet>
4. <description></description>
6. <display-name>abc</display-name>
8. <servlet-name>abc</servlet-name>
10. <servlet-class>com. ABC</servlet-class>
12. </servlet>
14. <servlet-mapping>
16. <servlet-name>abc</servlet-name>
18. <url-pattern>/abc</url-pattern>
20. </servlet-mapping>

Abstract out a tool request class

Java code

2. Package http;
6. Import Java.io.BufferedReader;
8. Import Java.io.InputStreamReader;
10. Import Java.io.OutputStreamWriter;
12. Import java.net.HttpURLConnection;
14. Import Java.net.URL;
16. Import Java.util.Map;
18. Import Java.util.Map.Entry;
22. Public class Httputil {
26. public static string http (string URL, map<string, string> params) {
28. URL u = null;
30. HttpURLConnection con = null;
32. //Build request Parameters
34. StringBuffer sb = new StringBuffer ();
36. if (params! = null) {
38. for (entry<string, string> e:params.entryset ()) {
40. Sb.append (E.getkey ());
42. Sb.append ("=");
44. Sb.append (E.getvalue ());
46. Sb.append ("&");
48. }
50. Sb.substring (0, Sb.length ()- 1);
52. }
54. System.out.println ("send_url:" + URL);
56. System.out.println ("send_data:" + sb.tostring ());
58. //Try to send a request
60. try {
62. u = new URL (URL);
64. Con = (httpurlconnection) u.openconnection ();
66. ////Post can only be uppercase, strictly limited, post will not recognize
68. Con.setrequestmethod ("POST");
70. Con.setdooutput (true);
72. Con.setdoinput (true);
74. Con.setusecaches (false);
76. Con.setrequestproperty ("Content-type", "application/x-www-form-urlencoded");
78. OutputStreamWriter OSW = new OutputStreamWriter (Con.getoutputstream (), "UTF-8");
80. Osw.write (Sb.tostring ());
82. Osw.flush ();
84. Osw.close ();
86. } catch (Exception e) {
88. E.printstacktrace ();
90. } finally {
92. if (con! = null) {
94. Con.disconnect ();
96. }
98. }
102. //Read back content
104. StringBuffer buffer = new StringBuffer ();
106. try {
108. //must have a return value, otherwise the request cannot be sent to the server side.
110. BufferedReader br = new BufferedReader (new InputStreamReader (Con.getinputstream (), "UTF-8"));
112. String temp;
114. While (temp = br.readline ()) = null) {
116. Buffer.append (temp);
118. Buffer.append ("\ n");
120. }
122. } catch (Exception e) {
124. E.printstacktrace ();
126. }
130. return buffer.tostring ();
132. }
136. }

Note: Be sure to get the return value, otherwise the request cannot be reached.

ReadLine () is a blocking method that waits for a response from the server or waits

Con.setdooutput (TRUE); This representation is to send a request to the URL address, without which the server will not respond.

Parameters are passed in a way similar to adding "? key=value&key1=value1" after the URL.

Test class

Java code

2. @Test
4. public void Test3 () {
6. Map parames = new hashmap<string, string> ();
8. Parames.put ("param1", "Param1_value");
10. Parames.put ("param2", "Param2_value");
12. Parames.put ("param3", "Param3_value");
14. If there is an AAA parameter in the Address bar, the address bar is selected by default, and if not, select the parameter to add
16. Parames.put ("AAA", "Aaa_value");
18. Httputil.http ("http://localhost:8080/a/Abc?aaa=dddd", parames);
20. }

Java sends HTTP requests (submits form form)