IDEA整合SSM，并使用PageHelper实现分页功能(超完整版)

使用到的技术：

• Spring、SpringMVC、Mybatis
• Maven
• MySQL(版本:8.0.23)
• Bootstrap
• PageHelper

创建一个Maven项目，选择webapp

在pom文件中导入相关依赖

<dependencies>
        <!--分页插件-->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
            <version>5.2.1</version>
        </dependency>
        <!--Junit-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13</version>
        </dependency>
        <!--数据库驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.23</version>
        </dependency>
        <!-- 数据库连接池 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.2.6</version>
        </dependency>

        <!--Servlet - JSP -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <version>2.5</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>jsp-api</artifactId>
            <version>2.1</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>

        <!--Mybatis-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.7</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.6</version>
        </dependency>

        <!--Spring-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.2.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.3.9</version>
        </dependency>

        <!--lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.12</version>
            <scope>provided</scope>
        </dependency>

        <!--jackson-->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.12.3</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.12.3</version>
        </dependency>

        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
    </dependencies>

配置web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">
    <!--配置DispatcherServlet，是SpringMVC的核心，又名前端控制器；用于拦截符合配置的 url 请求、分发请求-->
    <servlet>
        <servlet-name>springmvc</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <!--DispatcherServlet需要绑定Spring的配置文件-->
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:applicationContext.xml</param-value>
        </init-param>
        <!--设置启动级别1：随着服务器的启动而启动-->
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>springmvc</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <!--配置过滤器，防止乱码-->
    <filter>
        <filter-name>encoding</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>utf-8</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>encoding</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
</web-app>

创建spring-mvc.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/mvc
       https://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <!--开启mvc的注解支持-->
    <!--<mvc:annotation-driven/>-->
    <!--开启mvc的注解支持，同时解决json乱码问题，这是固定的，记住怎么使用就可以-->
    <mvc:annotation-driven>
        <mvc:message-converters register-defaults="true">
            <bean class="org.springframework.http.converter.StringHttpMessageConverter">
                <constructor-arg value="UTF-8"/>
            </bean>
            <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
                <property name="objectMapper">
                    <bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
                        <property name="failOnEmptyBeans" value="false"/>
                    </bean>
                </property>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>

    <!-- 让Spring MVC不处理静态资源，比如.css .js .mp4 .jpg .html等 -->
    <mvc:default-servlet-handler/>

    <!--配置视图解析器-->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/"/>
        <property name="suffix" value=".jsp"/>
    </bean>
</beans>

创建mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>

    <!--设置-->
    <settings>
        <!--设置日志-->
        <setting name="logImpl" value="LOG4J"/>
    </settings>

    <!--起别名-->
    <typeAliases>
        <package name="com.bao.pojo"/>
    </typeAliases>

    <!--引入pageHelper分页插件，注意整个plugins标签位置,位置不对会报错！-->
    <plugins>
        <plugin interceptor="com.github.pagehelper.PageInterceptor"></plugin>
    </plugins>

    <!--关联mapper.xml文件-->
    <mappers>
        <mapper resource="mapper/UserMapper.xml"/>
<!--        <mapper class="com.bao.mapper.UserMapper"/>-->
    </mappers>
    
</configuration>

创建UserMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.bao.mapper.UserMapper">

    <!--增-->
    <insert id="addUser" parameterType="user">
        insert into user(name,gender,age,address,qq,email)
        values(#{name},#{gender},#{age},#{address},#{qq},#{email})
    </insert>

    <!--删-->
    <delete id="deleteUser" parameterType="int">
        delete from user where id = #{id}
    </delete>

    <!--改-->
    <update id="updateUser" parameterType="user">
        update user set name=#{name},gender=#{gender},age=#{age},address=#{address},qq=#{qq},email=#{email} where id=#{id}
    </update>

    <!--查所有-->
    <select id="queryAllUser" resultType="user">
        select * from user
    </select>

    <!--根据id查一个-->
    <select id="queryUserById" resultType="user" parameterType="int">
        select * from user where id=#{id}
    </select>

    <!--根据条件查询-->
    <select id="conditionQuery" resultType="user" parameterType="user">
        select * from user
        <where>
            <if test="name != null and name != ''">
                name = #{name}
            </if>
            <if test="gender != null and gender != ''">
                and gender = #{gender}
            </if>
            <if test="address != null and address != ''">
                and address = #{address}
            </if>
        </where>
    </select>

</mapper>

创建spring-mapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">

    <!--导入druid.properties进行关联-->
    <context:property-placeholder location="classpath:druid.properties"/>
    <!--配置数据库连接池-->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="${jdbc.driverClassName}"/>
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>

    <!--配置SqlSessionFactory对象,该对象可以生成SqlSession对象-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!--连接数据源-->
        <property name="dataSource" ref="dataSource"/>
        <!--绑定Mybatis的配置文件-->
        <property name="configLocation" value="classpath:mybatis-config.xml"/>

    </bean>

    <!--配置MapperScannerConfigurer，将创建的接口的都自动注入到了SqlSessionFactory中，
        给每个接口创建了实例-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!--确定哪个包下的接口需要创建实体类-->
        <property name="basePackage" value="com.bao.mapper"/>
        <!--指定需要注入到哪一个SqlSessionFactory中-->
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
    </bean>

</beans>

配置druid.properties

jdbc.driverClassName=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/ssmtest?useSSL=true&useUnicode=true&characterEncoding=utf8
jdbc.username=mvctest
jdbc.password=mvctest

配置log4j.properties

log4j.rootLogger=DEBUG,console,file
log4j.appender.console = org.apache.log4j.ConsoleAppender 
log4j.appender.console.Target = System.out
log4j.appender.console.Threshold=DEBUG
log4j.appender.console.layout = org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern=[%c]-%m%n
log4j.appender.file = org.apache.log4j.RollingFileAppender
log4j.appender.file.File=./log/bao.log
log4j.appender.file.MaxFileSize=10mb
log4j.appender.file.Threshold=DEBUG
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=[%p][%d{yy-MM-dd}][%c]%m%n
log4j.logger.org.mybatis=DEBUG
log4j.logger.java.sql=DEBUG
log4j.logger.java.sql.Statement=DEBUG
log4j.logger.java.sql.ResultSet=DEBUG
log4j.logger.java.sql.PreparedStatement=DEBUG

创建spring-service.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">

    <!-- 配置事务管理器 -->
    <!--1.创建事务管理器-->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <constructor-arg ref="dataSource" />
    </bean>

    <!--2.开启事务注解，需要导入tx命名空间-->
    <!--transaction-manager="transactionManager" : 绑定事务管理器-->
    <tx:annotation-driven transaction-manager="transactionManager"/>

</beans>

创建applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">
	
   	
    <context:component-scan base-package="com.bao"/>
    <import resource="spring-mapper.xml"/>
    <import resource="spring-service.xml"/>
    <import resource="spring-mvc.xml"/>
    
</beans>

创建User类

package com.bao.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.springframework.stereotype.Component;

/**
 * @author Arvinsblog
 * Date:2021/9/26
 * Time:20:50
 */
@Data
@AllArgsConstructor
@NoArgsConstructor
@Component
public class User {
    private Integer id;
    private String username;
    private String password;
    private String name;
    private String gender;
    private Integer age;
    private String address;
    private String qq;
    private String email;

}

创建UserMapper

package com.bao.mapper;

import com.bao.pojo.User;
import org.springframework.stereotype.Component;

import java.util.List;

/**
 * @author Arvinsblog
 * Date:2021/9/26
 * Time:20:49
 */
@Component
public interface UserMapper {
//    增
    public int addUser(User user);
//    删
    public int deleteUser(int id);
//    改
    public int updateUser(User user);
//    查所有
    public List<User> queryAllUser();
//    根据id查询
    public User queryUserById(int id);
//    条件查询
    public List<User> conditionQuery(User user);
}

创建UserService

package com.bao.service;

import com.bao.pojo.User;
import org.apache.ibatis.annotations.Select;
import org.springframework.stereotype.Component;

import java.util.List;
import java.util.Map;

/**
 * @author Arvinsblog
 * Date:2021/9/26
 * Time:20:58
 */
@Component
public interface UserService {
    //    增
    public int addUser(User user);
    //    删
    public int deleteUser(int id);
    //    改
    public int updateUser(User user);
    //    查所有
    public List<User> queryAllUser();
    //    根据id查询
    public User queryUserById(int id);
    //    条件查询
    public List<User> conditionQuery(User user);
}

创建接口实现类UserServiceImpl

package com.bao.service.Impl;

import com.bao.mapper.UserMapper;
import com.bao.pojo.User;
import com.bao.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * @author Arvinsblog
 * Date:2021/9/26
 * Time:20:59
 */
@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserMapper userMapper;

    @Override
    public int addUser(User user) {
        return userMapper.addUser(user);
    }

    @Override
    public int deleteUser(int id) {
        return userMapper.deleteUser(id);
    }

    @Override
    public int updateUser(User user) {
        return userMapper.updateUser(user);
    }

    @Override
    public List<User> queryAllUser() {
        return userMapper.queryAllUser();
    }

    @Override
    public User queryUserById(int id) {
        return userMapper.queryUserById(id);
    }

    @Override
    public List<User> conditionQuery(User user) {
        return userMapper.conditionQuery(user);
    }
}

创建Controller

package com.bao.controller;

import com.bao.pojo.User;
import com.bao.service.Impl.UserServiceImpl;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;

import java.util.List;

/**
 * @author Arvinsblog
 * Date:2021/9/26
 * Time:22:24
 */
@Component
@RequestMapping("/user")
public class UserController {
    @Autowired
    private UserServiceImpl userServiceImpl;

    //查询所有并分页显示
    @GetMapping("/list")
    public String queryAllUser(@RequestParam(value = "page", defaultValue = "1") Integer page, Model model){
        //获取指定页数据，每页显示8条数据
        PageHelper.startPage(page, 8);
        //紧跟的第一个select方法被分页
        List<User> users = userServiceImpl.queryAllUser();
        model.addAttribute("users",users);
        //使用PageInfo包装数据 navigatePages表示导航标签的数量
        PageInfo pageInfo = new PageInfo(users, 5);
        model.addAttribute("pageInfo", pageInfo);
        return "user/list";
    }

    //查所有
//    @GetMapping("/list")
////    @ResponseBody
//    public String queryAllUser(Model model){
//        List<User> users = userServiceImpl.queryAllUser();
//        model.addAttribute("users",users);
//        return "user/list";
//    }


}

项目结构

创建lib文件夹，导入依赖（否则Tomcat无法启动）

​

​

​

创建Tomcat,并启动

注意不要选成TomEE Server

​

​

​

创建list.jsp页面负责显示数据，实现分页效果

<%--
  Created by IntelliJ IDEA.
  User: ZQ
  Date: 2021/9/27
  Time: 9:33
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
    <title>用户展示</title>
    <link rel="stylesheet" href="http://cdn.bootcss.com/bootstrap/3.3.0/css/bootstrap.min.css">
    <!-- jQuery文件。务必在bootstrap.min.js 之前引入 -->
    <script src="http://cdn.bootcss.com/jquery/1.11.1/jquery.min.js"></script>
    <script src="http://cdn.bootcss.com/bootstrap/3.3.0/js/bootstrap.min.js"></script>
</head>
<body>

<div style="width: 1200px;margin: auto" >
    <div>
        <h4 align="center">用户展示</h4>
    </div>
    <div>
        <form style="float: left;margin: 5px;" class="form-inline" action="${pageContext.request.contextPath}/user/conditionQuery" method="get">
            <div class="form-group">
                <label for="name">姓名</label>
                <input type="text" name="name" class="form-control" id="name" >
            </div>
            <div class="form-group">
                <label for="gender">性别</label>
                <input type="text" name="gender" class="form-control" id="gender"  >
            </div>
            <div class="form-group">
                <label for="address">城市</label>
                <input type="text" name="address" class="form-control" id="address" >
            </div>

            <button type="submit" class="btn btn-success">查询</button>

        </form>

        <a style="float: right;margin: 5px;" class="btn btn-info" href="${pageContext.request.contextPath}/user/add.jsp">添加联系人</a>
    </div>

    <table class="table table-hover">
        <tr>
            <th>序号</th>
            <th>姓名</th>
            <th>性别</th>
            <th>年龄</th>
            <th>城市</th>
            <th>QQ</th>
            <th>邮箱</th>
            <th>操作</th>
        </tr>
        <c:forEach items="${users}" var="user" varStatus="s">
<%--        <c:forEach items="${pageInfo.list}" var="user" varStatus="s">--%>
            <tr>
                <td>${user.id}</td>
                <td>${user.name}</td>
                <td>${user.gender}</td>
                <td>${user.age}</td>
                <td>${user.address}</td>
                <td>${user.qq}</td>
                <td>${user.email}</td>
                <td>
                    <a class="btn btn-danger" href="${pageContext.request.contextPath}/user/delete/${user.id}">删除</a>
                    <a class="btn btn-primary" href="${pageContext.request.contextPath}/user/queryUserById/${user.id}">修改</a>
                </td>
            </tr>
        </c:forEach>
    </table>


    <%--分页导航标签--%>
    <div class="row">
        <div class="col-md-6">
            第${pageInfo.pageNum}页，共${pageInfo.pages}页，共${pageInfo.total}条记录
        </div>
        <div class="col-md-6 offset-md-4">
            <nav aria-label="Page navigation example">
                <ul class="pagination pagination-sm">
                    <li class="page-item"><a class="page-link" href="${pageContext.request.contextPath}/user/list?page=1">首页</a></li>
                    <c:if test="${pageInfo.hasPreviousPage}">
                        <li class="page-item"><a class="page-link"
                                                 href="${pageContext.request.contextPath}/user/list?page=${pageInfo.pageNum-1}">上一页</a></li>
                    </c:if>
                    <c:forEach items="${pageInfo.navigatepageNums}" var="page">
                        <c:if test="${page==pageInfo.pageNum}">
                            <li class="page-item active"><a class="page-link" href="#">${page}</a></li>
                        </c:if>
                        <c:if test="${page!=pageInfo.pageNum}">
                            <li class="page-item"><a class="page-link"
                                                     href="${pageContext.request.contextPath}/user/list?page=${page}">${page}</a></li>
                        </c:if>
                    </c:forEach>
                    <c:if test="${pageInfo.hasNextPage}">
                        <li class="page-item"><a class="page-link"
                                                 href="${pageContext.request.contextPath}/user/list?page=${pageInfo.pageNum+1}">下一页</a></li>
                    </c:if>
                    <li class="page-item"><a class="page-link" href="${pageContext.request.contextPath}/user/list?page=${pageInfo.pages}">末页</a>
                    </li>
                </ul>
            </nav>
        </div>
    </div>

</div>

</body>
</html>

在浏览器中请求页面，分页功能可正常使用（这里只演示了分页显示，增删改自行实现一下哦）

数据库命令

-- 1. 创建表
create table user(   
		id int primary key auto_increment,
		username varchar(50),
		password varchar(50),
		name varchar(20) not null,
		gender varchar(5),
		age int,
		address varchar(32),
		qq	varchar(20),
		email varchar(50)
	);
	
	
-- 2. 插入数据
	INSERT INTO USER(username,password,name,gender,age,address,qq,email)
	VALUES('zhangsan','123','张三','男',18,'北京','111','111@qq.com'),
('lisi','123','李四','女',19,'上海','222','222@qq.com'),
('wangwu','123','王五','男',20,'广州','333','333@qq.com'),
('zhaoliu','123','赵六','女',21,'深圳','444','444@qq.com'),
('sunqi','123','孙七','男',22,'北京','555','555@qq.com'),
('zhouba','123','周八','女',23,'上海','666','666@qq.com')