First Servlet

Posted by Moon-sky on September 25, 2016

First Servlet(Servlet 学习日记)

前期准备

  1. IDE: MyEclipse 2014或者更高 ### 详细步骤

  2. 新建一个web project

  3. 右键新建servlet 3.代码详细如下

     import java.io.DataOutputStream;
 import java.io.IOException;
 import java.io.PrintWriter;
	
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
	
 import net.sf.json.JSONObject;
	
 public class Test extends HttpServlet {

 /**
  * Constructor of the object.
  */
 public Test() {
     super();
 }

 /**
  * Destruction of the servlet. <br>
  */
 public void destroy() {
     super.destroy(); // Just puts "destroy" string in log
     // Put your code here
 }

 /**
  * The doGet method of the servlet. <br>
  *
  * This method is called when a form has its tag value method equals to get.
  * 
  * @param request the request send by the client to the server
  * @param response the response send by the server to the client
  * @throws ServletException if an error occurred
  * @throws IOException if an error occurred
  */
 public void doGet(HttpServletRequest request, HttpServletResponse response)
         throws ServletException, IOException {
     String username=request.getParameter("username");
     String password=request.getParameter("password");
     DataOutputStream outputStream=new DataOutputStream(response.getOutputStream());
     outputStream.writeChars("success");
		
     JSONObject obj=new JSONObject();
     obj.put("username", "moon-sky");
     obj.put("password", "hello");
     outputStream.writeChars(obj.toString());
     outputStream.close();
		
     /*response.setContentType("text/html");
     PrintWriter out = response.getWriter();
		
     out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
     out.println("<HTML>");
     out.println("  <HEAD><TITLE>A Servlet</TITLE></HEAD>");
     out.println("  <BODY>");
     out.print("    This is ");
     out.print(this.getClass());
     out.println(", using the GET method");
     out.println("  </BODY>");
     out.println("</HTML>");
     out.flush();
     out.close();*/
 }

 /**
  * The doPost method of the servlet. <br>
  *
  * This method is called when a form has its tag value method equals to post.
  * 
  * @param request the request send by the client to the server
  * @param response the response send by the server to the client
  * @throws ServletException if an error occurred
  * @throws IOException if an error occurred
  */
 public void doPost(HttpServletRequest request, HttpServletResponse response)
         throws ServletException, IOException {

     response.setContentType("text/html");
     PrintWriter out = response.getWriter();
     out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
     out.println("<HTML>");
     out.println("  <HEAD><TITLE>A Servlet</TITLE></HEAD>");
     out.println("  <BODY>");
     out.print("    This is ");
     out.print(this.getClass());
     out.println(", using the POST method");
     out.println("  </BODY>");
     out.println("</HTML>");
     out.flush();
     out.close();
 }

 /**
  * Initialization of the servlet. <br>
  *
  * @throws ServletException if an error occurs
  */
 public void init() throws ServletException {
     // Put your code here
 }

 }`
  4. 其中涉及到使用json包，这里还需要到一些挫折，刚开始的时候是按照Android 中的习惯，把json-lib-2.3-jdk15.jar直接添加进来，但是发现还是在运行过程中，报错java.lang.ClassNotFoundException: org.apache.commons.collections.map.ListOrderedMap，最终解决方法是直接把把jar包放到WEB-INF 的lib目录
  5. 最后一步，右键运行
  6. 然后在浏览器输入：
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