背景

比如需要在页面加载后，干某些事情，就需要自动调用Servlet去调用Java代码，以达到某种功能。

演示

web网页搭建好后，进入这个web页面，自动调用Servlet

Servlet输出Hello：

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源码

java项目结构如下：

这里要注意：使用了jquery.js，要把这个导入进去！

源码如下：

SomeInof.java

package my;

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;

public class SomeInfo extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
	public SomeInfo() {
		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 {

//		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();
		
		System.out.println("Hello");
	}

	/**
	 * 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
	}

}

index.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'index.jsp' starting page</title>
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	<!--
	<link rel="stylesheet" type="text/css" href="styles.css">
	-->
	
	<script src="jquery/jquery.js"></script>
  
  
  	<script type = "text/javascript">
  		
  			function autoLoad(){
  		
  				jQuery.ajax({
  					method: "GET",
  					url: "servlet/SomeInfo"
  				});
  			}
  	</script>
  	
  </head>
  <body onload = "autoLoad()">
  
  </body>
</html>

关键就是在<body onload = "autoLoad()">这个逻辑

Java web中使用JQuery加载某页面后，自动调用Servlet（GET方法，POST方法）

背景

演示

源码

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