查询用户的信息页面(Servlet)

目录

一.页面效果

二.需求

三. 技术选型：

四.设计架构

五. 准备工作（导入jar包、配置文件、工具类,创建数据库,创建用户类）

六.登录页面

七.查询所有用户

八. 添加联系人

九.删除某条记录

十.修改信息

十一. 删除选中

十二. 分页查询

十三. 条件查询

十四.service层和dao层

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一.页面效果

二.需求

简单功能：列表查询、登录、添加、删除、修改

复杂功能：删除选中、分页查询、条件查询

三. 技术选型：

Servlet+JSP+MySQL+JDBCTempleat+Duird（数据库连接池）+BeanUtils（封装数据）+Tomcat

四.设计架构

 

 

五. 准备工作（导入jar包、配置文件、工具类,创建数据库,创建用户类）

工具类

package util;

import com.alibaba.druid.pool.DruidDataSourceFactory;

import javax.sql.DataSource;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;

/**
 * JDBC工具类 使用Durid连接池
 */
public class JDBCUtils {

    private static DataSource ds ;
    static {

        try {
            //1.加载配置文件
            Properties pro = new Properties();
            //使用ClassLoader加载配置文件，获取字节输入流
            InputStream is = JDBCUtils.class.getClassLoader().getResourceAsStream("druid.properties");
            pro.load(is);

            //2.初始化连接池对象
            ds = DruidDataSourceFactory.createDataSource(pro);

        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 获取连接池对象
     */
    public static DataSource getDataSource(){
        return ds;
    }

    /**
     * 获取连接Connection对象
     */
    public static Connection getConnection() throws SQLException {
        return  ds.getConnection();
    }
}

数据库

CREATE DATABASE USER;
USE USER;
CREATE TABLE USER(
	id INT PRIMARY KEY AUTO_INCREMENT,
	NAME VARCHAR(20) NOT NULL,
	gender VARCHAR(5),
	age INT,
	address VARCHAR(32),
	QQ VARCHAR(20),
	email VARCHAR(20)
);

用户类

public class User {
    private int id;
    private String name;
    private String gender;
    private int age;
    private String address;
    private String QQ;
    private String email;
    private String username;
    private String password;

    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;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getGender() {
        return gender;
    }
    public void setGender(String gender) {
        this.gender = gender;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    public String getQQ() {
        return QQ;
    }
    public void setQQ(String QQ) {
        this.QQ = QQ;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
}

dao层：操作数据库

public class UserDaoImpl implements UserDao {
    private JdbcTemplate template = new JdbcTemplate(JDBCUtils.getDataSource());
    @Override
    public List findAll() {
        //使用JDBC操作数据库
        String sql = "select * from user";
        List users = template.query(sql, new BeanPropertyRowMapper<>(User.class));
        return users;
    }
    //根据用户名和密码查询用户
    @Override
    public User findUserByUsernameAndPassword(String username, String password) {
        try {
            String sql ="select * from user where username = ? and password = ?";
            User user = template.queryForObject(sql, new BeanPropertyRowMapper<>(User.class), username, password);
            return user;
        }catch (Exception e){
            e.printStackTrace();
            return null;
        }
    }
    //添加用户
    @Override
    public void add(User user) {
        String sql = "insert into user values(null,?,?,?,?,?,?,null,null)";
        //执行sql
        template.update(sql,user.getName(),user.getGender(),user.getAge(),user.getAddress(),user.getQQ(),user.getEmail());
    }

    @Override
    public void delete(int id) {
        String sql = "delete from user where id = ?";
        //执行sql
        template.update(sql,id);
    }

    @Override
    public User findById(int id) {
        String sql = "select * from user where id = ?";
        return template.queryForObject(sql,new BeanPropertyRowMapper<>(User.class),id);
    }

    @Override
    public void update(User user) {
        String sql = "update user set name = ?, gender = ?, age = ?, address = ?, qq = ?, email = ? where id = ?";
        template.update(sql,user.getName(),user.getGender(),user.getAge(),user.getAddress(),user.getQQ(),user.getEmail(),user.getId());
    }

    @Override
    public int findTotalCount() {
        String sql = "select count(*) from user";
        return template.queryForObject(sql,Integer.class);
    }

    @Override
    public List findByPage(int start, int rows) {
        String sql = "select * from user limit ? ,?";
        return template.query(sql,new BeanPropertyRowMapper<>(User.class),start,rows);
    }

    @Override
    public int findTotalByCondition(Map condition) {
        //定义初始sql模板
        String sql = "select count(*) from user where 1 = 1 ";//1=1为了方便加and
        StringBuilder sb = new StringBuilder(sql);
        //定义参数的集合
        List