hello2源码解析

缺乏、安全感 2022-01-09 06:57 139阅读 0赞

GreetingServlet.java源码：

@WebServlet("/greeting")    //以@WebServlet注释开头，表示在根目录下使用/greeting来访问  
  public class GreetingServlet extends HttpServlet

\{  
     @Override  
      public void doGet(HttpServletRequest request,    //重写了doGet方法，实现GET HTTP方法  
       HttpServletResponse response)  
       throws ServletException, IOException

\{  
   
         response.setContentType("text/html");    //指定响应页面的类型为html  
        response.setBufferSize(8192);    //指定缓冲区大小8192  
         try (PrintWriter out = response.getWriter()) \{    //实例化对象out,作为向html页面输出的对象  
              
             //使用println属性，向html页面输出html标签,这里输出的是：     
               
  
            out.println("<html lang=\\"en\\">"  
                     + "<head><title>Servlet Hello</title></head>");  
              
                  //使用println属性，向html页面输出html标签  
              
             out.println("<body  bgcolor=\\"\#ffffff\\">"  
                     + "<img src=\\"resources/images/duke.waving.gif\\" "  
                    + "alt=\\"Duke waving his hand\\">"  
                     + "<form method=\\"get\\">"  
                     + "<h2>Hello, my name is Duke. What‘s yours?</h2>"  
                     + "<input title=\\"My name is: \\" type=\\"text\\" "  
                     + "name=\\"username\\" size=\\"25\\"/>"  
                    + "<p></p>"  
                     + "<input type=\\"submit\\" value=\\"Submit\\"/>"  
                     + "<input type=\\"reset\\" value=\\"Reset\\"/>"  
                     + "</form>");

//使用println属性，向html页面输出html标签  
              
            
             String username = request.getParameter("username");   //使用一个字符串username来获取，第一个input标签内的username的值  
             if (username != null && username.length() > 0) \{  
                 RequestDispatcher dispatcher =  
                         getServletContext().getRequestDispatcher("/response");  
                         //指定要跳转的页面相对于上下文根的URL模式为/response  
                  
                 if (dispatcher != null) \{  
                       
                     dispatcher.include(request, response);//整合request, response然后跳转  
                 \}  
             \}  
               
             out.println("</body></html>");//使用println属性，向html页面输出html标签  
         \}  
     \}

ResponseServlet.java源码：

@WebServlet("/response")    //以@WebServlet注释开头，表示在根目录下使用/response来访问。  
  public class ResponseServlet extends HttpServlet \{  
   
      @Override  
     public void doGet(HttpServletRequest request,    //重写了doGet方法，实现GET HTTP方法  
             HttpServletResponse response)  
              throws ServletException, IOException \{  
          try (PrintWriter out = response.getWriter()) \{        //实例化对象out,作为向html页面输出的对象  
             String username = request.getParameter("username");        //接收来自greting页面请求中的input标签中输入的username             if (username != null && username.length() > 0）\{

out.println("<h2>Hello, " + username + "!</h2>");//使用println属性，向html页面输出html标签  
             \}  
         \}  
     \}

转载于:https://www.cnblogs.com/railgun1/p/10836089.html