• java servlet练习测试


    步骤:

    0、首先创建web project,工程名:test_servlet

    1、编写Servlet,TestServlet.java文件内容:

    package com.ouyang.servlet;
    
    import java.io.IOException;
    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.PreparedStatement;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.util.ArrayList;
    import java.util.List;
    
    import javax.servlet.RequestDispatcher;
    import javax.servlet.ServletException;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    @SuppressWarnings("serial")
    public class TestServlet extends HttpServlet {
    
    	@Override
    	protected void doGet(HttpServletRequest req, HttpServletResponse resp)
    			throws ServletException, IOException {
    
    		req.setCharacterEncoding("utf-8");
    		
    		String url = "jdbc:mysql://localhost:3306/test01";
    		String user = "root";
    		String password = "xxx";
    
    		Connection connection = null;
    		PreparedStatement preparedStatement = null;
    		ResultSet resultSet = null;
    		String sql = "select id, name, age from individual_information";
    		List<List<String>> record = new ArrayList<>();
    
    		try {
    			Class.forName("com.mysql.jdbc.Driver");
    			connection = DriverManager.getConnection(url, user, password);
    			preparedStatement = connection.prepareStatement(sql);
    			resultSet = preparedStatement.executeQuery();
    
    			List<String> tmp = new ArrayList<>();
    			while (resultSet.next()) {
    				tmp.add(resultSet.getString("id"));
    				tmp.add(resultSet.getString("name"));
    				tmp.add(resultSet.getString("age"));
    				record.add(new ArrayList<String>(tmp));
    				tmp.clear();
    			}
    
    		} catch (ClassNotFoundException e) {
    			e.printStackTrace();
    		} catch (SQLException e) {
    			e.printStackTrace();
    		}
    
    		req.setAttribute("individual_information", record);
    		RequestDispatcher requestDispatcher = req
    				.getRequestDispatcher("get_info.jsp");
    		requestDispatcher.forward(req, resp);
    
    	}
    
    	@Override
    	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
    			throws ServletException, IOException {
    		this.doGet(req, resp);
    	}
    }
    

      

    2、将servlet添加到web.xml, 添加后的文件内容

    <?xml version="1.0" encoding="UTF-8"?>
    <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
      <display-name>test_web</display-name>
      <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
      </welcome-file-list>
      
      <servlet>
      	<servlet-name>testServlet</servlet-name>
      	<servlet-class>com.ouyang.servlet.TestServlet</servlet-class>
      </servlet>
      <servlet-mapping>
      	<servlet-name>testServlet</servlet-name>
      	<url-pattern>/testServlet</url-pattern>
      </servlet-mapping>  
      
    </web-app>
    

      

    3、编写跳转页面 get_info.jsp

    <%@page import="java.util.List"%>
    <%@ page language="java" contentType="text/html; charset=utf-8"
        pageEncoding="utf-8"%>
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <title>get_info</title>
    </head>
    <body>
    	<%
    		@SuppressWarnings("unchecked")
    		List<List<String>> record = (List<List<String>>)request.getAttribute("individual_information");
    		for(List<String> list : record){
    			out.println("<li>" + list.toString() + "</li>");
    		}
    	
    	%>
    </body>
    </html>
    

      

    【测试】

    访问:http://localhost/test_servlet/testServlet

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  • 原文地址:https://www.cnblogs.com/ouyxy/p/7216804.html
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