JSP+Servlet+MySQL完成将数据库中的数据显示到页面
步骤：
1 先写Servlet代码，首先导入mysql-connector-java-5.1.40-bin.jar，在init()方法中加载jdbc驱动，在doGet()方法中获取数据库连接对象，然后获取SQL的操作对象。
代码如下：
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.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import bean.User;
public class JdbcJspServlet extends HttpServlet {
@Override
public void init() throws ServletException {
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
try {
List<User> userList = new ArrayList<>();
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/java","root","123456");
ps = conn.prepareStatement("select * from tb_user");
rs = ps.executeQuery();
while(rs.next()){
String name = rs.getString("userName");
String password = rs.getString("userPwd");
User user = new User(name, password);
userList.add(user);
}
req.setAttribute("userList", userList);
req.getRequestDispatcher("home.jsp").forward(req, resp);
} catch (SQLException e) {
e.printStackTrace();
}finally {
try {
if(rs != null){
rs.close();
}
if(ps!=null){
ps.close();
}
if(conn!=null){
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doGet(req, resp);
}
}
2 在1中要用到一个实体类User,所以要写一个User类，把查询的结果放到一个ArrayList集合中。
代码如下：
import java.io.Serializable;
public class User implements Serializable {
private String name;
private String password;
public User() {
super();
// TODO Auto-generated constructor stub
}
public User(String name, String password) {
super();
this.name = name;
this.password = password;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}3 配置web.xml文件：
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
<display-name>Day42_jdbc_jsp_servlet</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>JdbcJspServlet</servlet-name>
<servlet-class>com.jdbcjspservlet.JdbcJspServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>JdbcJspServlet</servlet-name>
<url-pattern>/jdbcJspServlet.do</url-pattern>
</servlet-mapping>
</web-app>4 写要将数据显示的jsp页面
<%@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>Insert title here</title>
</head>
<body>
<ul>
<%
Object obj = request.getAttribute("userList");
List<User> userList = null;
if(obj instanceof List){
userList = (List<User>)obj;
}
if(userList!=null){
for(User user:userList){
String userinfo = user.getName()+"---"+user.getPassword();
%>
<li><%=userinfo %></li>
<%
}
}
%>
</ul>
</body>
</html>5 启动TomCat服务器，在浏览器地址栏输入地址即可将查询到的数据库数据显示到网页。
声明：该文观点仅代表作者本人，牛骨文系教育信息发布平台，牛骨文仅提供信息存储空间服务。
- 上一篇： URL中传参带有%2F等特殊字符
- 下一篇： thinkphp 对同一个字段 有多个条件的查询
