spring的mybatis-puls 配置，增删改查操作,分页

pom

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>zys_</groupId>
  <artifactId>mybatis_plus1</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  
  <properties>
        <mybatisplus.version>3.2.0</mybatisplus.version>
        <spring.version>4.3.24.RELEASE</spring.version>
        <mysql.version>8.0.17</mysql.version>
        <!-- 注意只能使用2.0以下的版本 -->
        <log4j.version>1.2.17</log4j.version>
        <lombok.version>1.18.8</lombok.version>
    </properties>
  
  
  <dependencies>
              <!-- spring配置 -->
        <!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>${lombok.version}</version>
            <scope>provided</scope>
        </dependency>

        <!-- 引入spring -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aspects</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-expression</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <!-- mysql数据库驱动 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>${mysql.version}</version>
        </dependency>
        <!-- log4j -->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>${log4j.version}</version>
        </dependency>


        <!-- 引入mp -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus</artifactId>
            <version>${mybatisplus.version}</version>
        </dependency>

    </dependencies>

  
</project>

配置

driver=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://127.0.0.1:3306/test_demo?useUnicode=true&characterEncoding=utf8&useSSL=true&serverTimezone=UTC
user=root
password=root

<!-- dao层的配置：核心是要产生 Mapper代理类对象 1.引入数据库配置信息 2.数据源配置 3.SqlSessionFactory 
        4.产生Mapper接口的代理类对象 -->
    <!-- 1.引入数据库配置信息 -->
    <context:property-placeholder
        location="classpath:db.properties" system-properties-mode="FALLBACK" />
    <!--2.数据源配置 -->
    <bean id="dataSource"
        class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="${driver}"></property>
        <property name="url" value="${url}"></property>
        <property name="username" value="${user}"></property>
        <property name="password" value="${password}"></property>
    </bean>

    <!-- 3.SqlSessionFactory -->
    <bean id="sqlSessionFactory"
        class="com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"></property>
        
        <property name="globalConfig" ref="globalConfig"></property>
        <!-- 加载xxMapper.xml -->
        <property name="mapperLocations">
            <array>
                <value>classpath:mapper/*Mapper.xml</value>
            </array>
        </property>
        <!-- 配置分页插件 -->
        <property name="plugins">
            <array>
                <bean class="com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor">
                </bean>
            </array>
        </property>
    </bean>
    <!-- 声明全局配置 -->
    <bean id="globalConfig" class="com.baomidou.mybatisplus.core.config.GlobalConfig">
        <!-- 指定主键自动增长类型 -->
        <property name="dbConfig" ref="dbConfig"></property>
    </bean>
    <bean id="dbConfig" class="com.baomidou.mybatisplus.core.config.GlobalConfig.DbConfig">
        <property name="idType" value="AUTO"></property>
    </bean>
    
    <!-- 4.产生Mapper接口的代理类对象 -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!-- 需要生成代理类对象的mapper接口包 -->
        <property name="basePackage"
            value="com.sxt.mapper"></property>
        <!-- sqlSessionFactory 的name 用于为代理类中生成SqlSession -->
        <property name="sqlSessionFactoryBeanName"
            value="sqlSessionFactory"></property>
    </bean>

创建数据库

提示：使用query5方法需要配置分页配置

/**
 * mybatisplus的配置类
 * @author LJH
 *
 */
@Configuration
@ConditionalOnClass(value= {PaginationInterceptor.class})
public class MybatisPlusConfig {
    
    @Bean
    public PaginationInterceptor  paginationInterceptor() {
        return new PaginationInterceptor();
    }

}

实体类

import java.io.Serializable;
import java.util.Date;

import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;

@Data
@AllArgsConstructor
@NoArgsConstructor
@ToString
@TableName(value="test_user")//建立User.class和数据的test_user表的关系
public class User implements Serializable{
    
    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    
    @TableId(value="id")  //代表它是主键
    private Integer id;
    private String name;
    private String pwd;
}

创建mapper接口

public interface UserMapper extends BaseMapper<User>{

}

创建一个test类

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.baomidou.mybatisplus.core.conditions.Wrapper;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.conditions.update.UpdateWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.sxt.domain.User;
import com.sxt.mapper.UserMapper;

public class TestApp {
    
    
    public static void main(String[] args) {
        ApplicationContext context=new ClassPathXmlApplicationContext("classpath:applicationContext.xml");
        UserMapper userMapper=context.getBean(UserMapper.class);
        User user = new User(1,"xiao","666");

        //插入
        //userMapper.insert(user);

        //更新
        //updateUser(userMapper);
        //删除
        //deleteUser(userMapper);
        //查询
        query1(userMapper);
        //c查询 返回user集合
        //query2(userMapper);
        //map的用法为and拼接  SELECT id,name,pwd FROM test_user WHERE name = ? AND pwd = ?
        //query3(userMapper);
        //模糊查询
//        query4(userMapper,"xia");

//        query5(userMapper);

        System.out.println("操作成功");
        
    }
    
    private static void query5(UserMapper userMapper) {
        IPage<User> page=new Page<>(1, 5);
        userMapper.selectPage(page, null);
        long total = page.getTotal();
        System.out.println("总条数:"+total);
        List<User> list = page.getRecords();
        print(list);

    }

    private static void query4(UserMapper userMapper,String name) {
//        Integer count = userMapper.selectCount(null);
        QueryWrapper<User> queryWrapper=new QueryWrapper<>();
        //模糊查询  判断name不为空
        queryWrapper.like(name!=null, "name", name);
        Integer selectCount = userMapper.selectCount(queryWrapper);
        System.out.println(selectCount);
    }

    /**
     * 查询  map为and拼接条件
     * @param userMapper
     */
    private static void query3(UserMapper userMapper) {
        Map<String, Object> columnMap=new HashMap<>();
        columnMap.put("name", "xiao");
        columnMap.put("pwd", "q");
        List<User> list = userMapper.selectByMap(columnMap);
        print(list);
    }



    /**
     * 查询 返回user集合
     * @param userMapper
     */
    private static void query2(UserMapper userMapper) {
        Collection<Serializable> idList=new ArrayList<Serializable>();
        idList.add(2);
        idList.add(3);
        idList.add(4);
        List<User> list = userMapper.selectBatchIds(idList);
        print(list);
    }
    /**
     * 查询
     * @param userMapper
     */
    private static void query1(UserMapper userMapper) {
        User user = userMapper.selectById(2);
        System.out.println(user);
    }

    /**
     * 删除用户
     * @param userMapper
     */
    private static void deleteUser(UserMapper userMapper) {
//        userMapper.deleteById(1);//根据主键删除
        //批量删除
//        Collection<Serializable> idList=new ArrayList<Serializable>();
//        idList.add(2);
//        idList.add(3);
//        userMapper.deleteBatchIds(idList);
        //批量and删除
//        Map<String, Object> columnMap=new HashMap<String, Object>();
//        columnMap.put("id", 6);
//        columnMap.put("name", "666");
//        userMapper.deleteByMap(columnMap);
        //区间删除
        QueryWrapper<User> wrapper=new QueryWrapper<>();
        wrapper.between("id", 1, 3);
        userMapper.delete(wrapper);

    }

    /**
     * 修改
     * @param userMapper
     */
    private static void updateUser(UserMapper userMapper) {
        //userMapper.updateById(new User(1, "q", "q"));//根据主键修改
        UpdateWrapper<User> updateWrapper=new UpdateWrapper<>();
//        updateWrapper.eq("id", 1);  //sql  ===where id=1
//        updateWrapper.between("id", 1, 3);
//        userMapper.update(new User(1, "q", "q"), updateWrapper);
    }

    private static void print(List<User> list) {
        for (User user : list) {
            System.out.println(user);
        }
    }

}