Jsp、Servlet、jdbc 完成简单登录注册

Jsp、Servlet、jdbc 完成简单登录注册

基于MVC模式开发JAVA WEB，实现简单登录注册，在以后会不断优化

开发环境：windows 7，jdk1.7

开发工具：Eclipse，tomcat7，MySQL server 5.7

依赖包：

项目结构

登录页面login.jsp

<%@ 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>用户登陆</title>
</head>
<body>
<form action="login" method="post">
用户账号<input type="text" name="userName"><br>
用户密码<input type="password" name="passWord">
<input type="submit" value="登录">
<a href="register.jsp">注册</a>
</form>
</body>
</html>

注册页面register.jsp

<%@ 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>用户注册</title>
</head>
<body>
<form action="register" method="post">
用户账号<input type="text" name="userName"><br>
用户密码<input type="password" name="passWord">
<input type="submit" value="注册">
<a href="login.jsp">返回</a>
</form>
</body>
</html>

登录进入管理页面manager.jsp

<%@ 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>管理界面</title>
</head>
<body>
管理界面......
</body>
</html>

web.xml配置

<?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" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" 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>day_22</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>login.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>login</servlet-name>
<servlet-class>com.ants.service.LoginService</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>login</servlet-name>
<url-pattern>/login</url-pattern>
</servlet-mapping>

<servlet>
<servlet-name>register</servlet-name>
<servlet-class>com.ants.service.RegisterService</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>register</servlet-name>
<url-pattern>/register</url-pattern>
</servlet-mapping>

</web-app>

DBUtil.java

package com.ants.util;

import java.sql.Connection;
import java.sql.ResultSet;

import java.sql.Statement;

import org.apache.commons.dbcp.BasicDataSource;

public class DBUtil {
private static BasicDataSource dataSource;

static{
//数据库连接池
dataSource = new BasicDataSource();
dataSource.setDriverClassName("com.mysql.jdbc.Driver");
dataSource.setUrl("jdbc:mysql://localhost:3306/test_4");
dataSource.setUsername("root");
dataSource.setPassword("123456");
//设置连接池的初始大小
dataSource.setInitialSize(5);
//设置连接池的最大值
dataSource.setMaxActive(20);
//设置最大的空闲时间,60秒之后自动回收空闲的数据库连接
dataSource.setMaxIdle(60);
//maxWait代表当connection用尽以后多久进行回收丢失连接
dataSource.setMaxWait(900);

}
//获取数据库连接
public static Connection getConnection() throws Exception{
return dataSource.getConnection();
}

public static void releseDataSource() throws Exception{
//释放数据库连接池
if(dataSource!=null){
dataSource.close();
}
}
//关闭以后释放数据库资源
public static void closeResource(Connection connection,Statement statement,ResultSet resultSet) throws Exception{
if(connection!=null){
connection.close();
}if(statement!=null){
statement.close();
}if(resultSet!=null){
resultSet.close();
}
}
}

UserDAO.java

package com.ants.dao;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

import com.ants.entity.User;
import com.ants.util.DBUtil;

public class UserDao {
public void save(User user){
Connection connection = null;
PreparedStatement statement=null;
try {
connection = DBUtil.getConnection();
//准备语句
String sql = "insert into tb_user(username,password) VALUES(?,?)";
statement=connection.prepareStatement(sql);
//绑定数据
statement.setString(1, user.getUsername());
statement.setString(2,user.getPassword());
//执行语句
statement.execute();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
finally{
try {
DBUtil.closeResource(connection, statement, null);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

public void deleteUser(User user){
Connection connection = null;
PreparedStatement statement=null;
try {
connection = DBUtil.getConnection();
//准备语句
String sql = "DELETE FROM tb_user where id=?";
statement=connection.prepareStatement(sql);
//4.绑定数据，索引是从1开始
//这是删除的绑定
statement.setInt(1, user.getId());
//5.执行语句
statement.execute();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
finally{
try {
DBUtil.closeResource(connection, statement, null);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

public void updateUser(User user){
Connection connection = null;
PreparedStatement statement=null;
try {
connection = DBUtil.getConnection();
//准备语句
String sql = "update tb_user SET `username`=? where id=?";
statement=connection.prepareStatement(sql);
//4.绑定数据，索引是从1开始
//这是修改的绑定语句
statement.setString(1, user.getUsername());
statement.setInt(2, user.getId());
//5.执行语句
statement.execute();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
finally{
try {
DBUtil.closeResource(connection, statement, null);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

public List<User> fidAll(String username){
ResultSet resultSet = null;
Connection connection=null;
//因为数据是从外面传进来的，所以我们使用占位符
PreparedStatement statement=null;
try {
connection = DBUtil.getConnection();
//3.准备语句
//这是查询的数据库语句
String sql = "SELECT * from tb_user where username = ?";
//创建预编译的,1指语句第一个?占位符
statement = connection.prepareStatement(sql);
statement.setString(1, username);
//5.执行语句
resultSet = statement.executeQuery();
List<User> au =new ArrayList<User>();

while (resultSet.next()) {
User user = new User();
user.setId(resultSet.getInt("id"));
user.setUsername(resultSet.getString("username"));
user.setPassword(resultSet.getString("password"));

au.add(user);
}
return au;
} catch (Exception e) {

e.printStackTrace();
}
finally{
try {
DBUtil.closeResource(connection, statement, resultSet);
} catch (Exception e) {
e.printStackTrace();
}
}
return null;
}

}

User.java

package com.ants.entity;

import java.io.Serializable;

public class User implements Serializable{

private static final long serialVersionUID = 1L;

private Integer id;
private String username;
private String password;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}

@Override
public String toString() {
return "User [id=" + id + ", userName=" + username + ", password=" + password + "]";
}
}

LoginServlet.java

package com.ants.service;

import java.io.IOException;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.ants.dao.UserDao;
import com.ants.entity.User;

public class LoginService extends HttpServlet{
private static final long serialVersionUID = 1L;

@Override
public void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//设置post请求的编码格式
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");

String name = request.getParameter("userName");
String pass = request.getParameter("passWord");
UserDao dao = new UserDao();
List<User> list = dao.fidAll(name);

for(User user1:list){
if(name.equals(user1.getUsername())&&pass.equals(user1.getPassword())){
request.getRequestDispatcher("/manager.jsp").forward(request, response);
return;
}else{
request.getRequestDispatcher("/login.jsp").forward(request, response);
return;
}
}
}
}

RegisterServlet.java

package com.ants.service;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.ants.dao.UserDao;
import com.ants.entity.User;

public class RegisterService extends HttpServlet {

private static final long serialVersionUID = 1L;

protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//设置post请求信息的编码格式
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
//得到用户名和密码从jsp页面获取
String username = request.getParameter("userName");
String password = request.getParameter("passWord");
//验证用户
System.err.println(username+password);

UserDao userDao = new UserDao();
User user = new User();

user.setUsername(username);
user.setPassword(password);

userDao.save(user);

request.getRequestDispatcher("/login.jsp").forward(request, response);

}

}

DBUtilTest.java

package com.ants.test;

import java.sql.Connection;

import com.ants.util.DBUtil;

public class DBUtilTest {
public static void main(String[] args) {
try {
Connection connection = DBUtil.getConnection();
System.out.println(connection);
} catch (Exception e) {
e.printStackTrace();
}
}
}

UserDaoTest.java

package com.ants.test;

import org.junit.Test;

import com.ants.dao.UserDao;
import com.ants.entity.User;

public class UserDaoTest {
@Test
public void save(){
UserDao userDao = new UserDao();
User user = new User();
user.setUsername("古威");
user.setPassword("456");

userDao.save(user);
}
}

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原文地址：https://www.cnblogs.com/TianMu/p/7650811.html