java_web learning-display data in mysql
1. Create database
create database animal;
create table animal(
sno int,
name varchar(20),
weight varcahr(20),
color varchar(20),
birth date
);
Insert data
insert into animal values('1','lion','200kg','yellow','2014-07-30'),('3','tiger','180kg','yellow',' 2010-02-14'),('2','monkey','20kg','brown','2003-04-14'),('6','elephant','1000kg','black ','2009-07-12'),('5','giraffe','700kg','yellow','2007-07-13');
As shown in the picture:
2. Create a web Project
Import five packages in the lib folder:
The project name is: Animal1
There are three packages in the project: entity, action, util
A jsp File: An.jsp
Code in ConnManager.java
1 package util; 2 3 import java.sql.Connection; 4 import java.sql.DriverManager; 5 6 public class ConnManager { 7 8 //数据库5大参数 9 private static final String IP = "127.0.0.1";10 private static final String PORT = "3306";11 private static final String DATABASE_NAME = "zhz";12 private static final String USER_NAME = "root";13 private static final String PASSWORD = "";14 private static final String DRIVER = "org.gjt.mm.mysql.Driver";15 16 public static Connection getConnection() throws Exception {17 String url = "jdbc:mysql://"+IP+":"+PORT+"/"+DATABASE_NAME+"?user="+USER_NAME+"&password="+PASSWORD+"";18 Class.forName(DRIVER);19 Connection conn = DriverManager.getConnection(url);20 return conn;21 }22 23 }
Code in Pig.java Code
1 package entity; 2 3 import java.util.Date; 4 5 public class Pig { 6 private Integer id=null; 7 private String name=null; 8 private String weight=null; 9 private String color=null;10 private Date birth=null;11 public Integer getId() {12 return id;13 }14 public void setId(Integer id) {15 this.id = id;16 }17 public String getName() {18 return name;19 }20 public void setName(String name) {21 this.name = name;22 }23 public String getWeight() {24 return weight;25 }26 public void setWeight(String weigth) {27 this.weight = weigth;28 }29 public String getColor() {30 return color;31 }32 public void setColor(String color) {33 this.color = color;34 }35 public Date getBirth() {36 return birth;37 }38 public void setBirth(Date birth) {39 this.birth = birth;40 }41 42 }
Code in showPig.java
1 package action; 2 3 import java.io.IOException; 4 import java.sql.Connection; 5 import java.sql.PreparedStatement; 6 import java.sql.ResultSet; 7 import java.util.ArrayList; 8 import java.util.List; 9 10 import javax.servlet.ServletException;11 import javax.servlet.annotation.WebServlet;12 import javax.servlet.http.HttpServlet;13 import javax.servlet.http.HttpServletRequest;14 import javax.servlet.http.HttpServletResponse;15 16 import entity.Pig;17 import util.ConnManager;18 19 @WebServlet("/showPig")20 public class showPig extends HttpServlet {21 private static final long serialVersionUID = 1L;22 23 24 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {25 try {26 Connection conn = ConnManager.getConnection();27 String sql = "select * from animal";28 PreparedStatement ps = conn.prepareStatement(sql);29 //建立一个池,用于存放数据30 List<Pig> pigList = new ArrayList<Pig>();31 ResultSet rs = ps.executeQuery();32 while(rs.next()){34 Integer id = rs.getInt("id");35 String name = rs.getString("name");36 String weight = rs.getString("weight");37 String color = rs.getString("color");38 java.sql.Date birth= rs.getDate("birth");39 Pig s = new Pig();40 s.setId(id);41 s.setName(name);42 s.setWeight(weight);43 s.setColor(color);44 s.setBirth(birth);45 pigList.add(s);46 }47 rs.close();48 ps.close();49 conn.close();50 request.setAttribute("pigList", pigList);51 request.getRequestDispatcher("An.jsp").forward(request, response);52 53 } catch (Exception e) {54 System.out.println("发生异常"+e.getMessage());55 }56 }57 58 59 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {60 61 doGet(request, response);62 }63 64 }
Code in An.jsp
1 <%@ page language="java" contentType="text/html; charset=UTF-8" 2 pageEncoding="UTF-8"%> 3 <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%> 4 <%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt"%> 5 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 6 <html> 7 <head> 8 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 9 <title>Insert title here</title>10 </head>11 <body>12 <table border = "2px" width = "80%">13 <tr>14 <td>编号</td>15 <td>名字</td>16 <td>体重</td>17 <td>颜色</td>18 <td>入园日期</td>19 </tr>20 <c:forEach var="L" items="${pigList}">21 <tr>22 <td>${L.id }</td>23 <td>${L.name }</td>24 <td>${L.weight }</td>25 <td>${L.color }</td>26 <td><fmt:formatDate value="${L.birth }" pattern="yyyy-MM-dd"></fmt:formatDate></td>27 </tr>28 </c:forEach>29 </table>30 </body>31 </html>
3. Running results
Run the Servlet, the running results are as shown in the figure:
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