hello2 source analysis
作者：互联网
1.GreetingServlet.java源码文件：
1 @WebServlet("/greeting") //以@WebServlet注释开头，注释指定相对于上下文根的URL模式，即在根目录下使用/greeting来访问
2 public class GreetingServlet extends HttpServlet {
3
4 @Override
5 public void doGet(HttpServletRequest request, //该servlet重写该doGet方法，实现GET HTTP方法
6 HttpServletResponse response)
7 throws ServletException, IOException {
8
9 response.setContentType("text/html"); //指定响应页面的类型为html
10 response.setBufferSize(8192); //指定缓冲区大小
11 try (PrintWriter out = response.getWriter()) { //实例化对象out,作为向html页面输出的对象
12
13 //使用println属性，向html页面输出html标签,这里输出的是：
14 //<html lang=en>
15 // <head>
16 // <title>Servlet Hello</title>
17 // </head>
18
19 out.println("<html lang=\"en\">"
20 + "<head><title>Servlet Hello</title></head>");
21
22 //使用println属性，向html页面输出html标签,这里输出的是：
23 //<body bgcolor=#ffffff>
24 // <img src=resources/images/duke.waving.gif alt=Duke waving his hand>
25 // <form method=get>
26 // <h2>Hello, my name is Duke. What's yours?</h2>
27 // <input title=My name is: type=text name=username size=25/>
28 // <p></p>
29 // <input type=submit value=Submit/>
30 // <input type=reset value=Reset/>
31 // </form>)
32
33 out.println("<body bgcolor=\"#ffffff\">"
34 + "<img src=\"resources/images/duke.waving.gif\" "
35 + "alt=\"Duke waving his hand\">"
36 + "<form method=\"get\">"
37 + "<h2>Hello, my name is Duke. What's yours?</h2>"
38 + "<input title=\"My name is: \" type=\"text\" "
39 + "name=\"username\" size=\"25\"/>"
40 + "<p></p>"
41 + "<input type=\"submit\" value=\"Submit\"/>"
42 + "<input type=\"reset\" value=\"Reset\"/>"
43 + "</form>");
44
45 //使用一个字符串username来获取，第一个input标签内的username的值
46 String username = request.getParameter("username");
47 if (username != null && username.length() > 0) {
48 RequestDispatcher dispatcher =
49 getServletContext().getRequestDispatcher("/response");
50 //指定要跳转的页面相对于上下文根的URL模式为/response
51
52 if (dispatcher != null) {
53 //整合request, response然后跳转
54 dispatcher.include(request, response);
55 }
56 }
57 //使用println属性，向html页面输出html标签,这里输出的是：
58 // </body>
59 //</html>
60 out.println("</body></html>");
61 }
62 }
63
64 @Override
65 public String getServletInfo() {
66 return "The Hello servlet says hello.";
67
68 }
69 }
2.ResponseServlet.java源码文件
1 @WebServlet("/response") //以@WebServlet注释开头，注释指定相对于上下文根的URL模式，
2 //即在根目录下使用/response来访问,这里作为greting页面的响应页面来实现访问
3 public class ResponseServlet extends HttpServlet {
4
5 @Override
6 public void doGet(HttpServletRequest request, ////该servlet重写该doGet方法，实现GET HTTP方法
7 HttpServletResponse response)
8 throws ServletException, IOException {
9 try (PrintWriter out = response.getWriter()) { //实例化对象out,作为向html页面输出的对象
10 //接收来自greting页面请求中的input标签中输入的username
11 String username = request.getParameter("username");
12 if (username != null && username.length() > 0) {
13 //使用println属性，向html页面输出html标签,这里输出的是：
14 //<h2>Hello,XXX(前面输入的username的值)!</h2>
15 out.println("<h2>Hello, " + username + "!</h2>");
16 }
17 }
18 }
19
20 @Override
21 public String getServletInfo() {
22 return "The Response servlet says hello.";
23
24 }
25 }标签：username,analysis,source,html,println,out,hello2,response,页面 来源： https://www.cnblogs.com/djh222/p/10605153.html