mybatis：DatetypeHandlers类型转换+plugin查询分页

mysql数据库

/*
Navicat MySQL Data Transfer

Source Server         : lijunxiang
Source Server Version : 80019
Source Host           : localhost:3306
Source Database       : test

Target Server Type    : MYSQL
Target Server Version : 80019
File Encoding         : 65001

Date: 2021-08-21 21:39:50
*/

SET FOREIGN_KEY_CHECKS=0;

-- ----------------------------
-- Table structure for user01
-- ----------------------------
DROP TABLE IF EXISTS `user01`;
CREATE TABLE `user01` (
  `id` int NOT NULL AUTO_INCREMENT,
  `username` varchar(255) DEFAULT NULL,
  `password` varchar(255) DEFAULT NULL,
  `birthday` bigint DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of user01
-- ----------------------------
INSERT INTO `user01` VALUES ('1', 'bdaj', 'bdha', '1629548933591');
INSERT INTO `user01` VALUES ('2', 'bdaj', 'bdha', '1629549730181');
INSERT INTO `user01` VALUES ('3', 'bdaj', 'bdha', '1629549734294');
INSERT INTO `user01` VALUES ('4', 'bdaj', 'bdha', '1629549739579');

User实体

package com.ljx.domain;

import java.util.Date;

public class User {
    
    
    private int id;
    private String username;
    private String password;
    private Date birthday;

    public int getId() {
    
    
        return id;
    }

    public void setId(int 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;
    }

    public Date getBirthday() {
    
    
        return birthday;
    }

    public void setBirthday(Date birthday) {
    
    
        this.birthday = birthday;
    }

    @Override
    public String toString() {
    
    
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                ", birthday=" + birthday +
                '}';
    }
}

DateTypeHandler

package com.ljx.handler;

import org.apache.ibatis.type.BaseTypeHandler;
import org.apache.ibatis.type.JdbcType;

import java.sql.CallableStatement;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Date;


public class DateTypeHandler extends BaseTypeHandler<Date> {
    
    
    @Override
//    将java类型转换为数据库需要的类型
    public void setNonNullParameter(PreparedStatement preparedStatement, int i, Date date, JdbcType jdbcType) throws SQLException {
    
    
        long time = date.getTime();
        preparedStatement.setLong(i,time);
    }

    @Override
    //将数据库类型转换为java类型
//    String参数 要转换的字段名称
//    ResultSet 查询出结果集
    public Date getNullableResult(ResultSet resultSet, String s) throws SQLException {
    
    
//        获得结果集中需要的数据（long）转换成Date类型 返回
        long aLong = resultSet.getLong(s);
        Date date = new Date(aLong);
        return date;
    }

    @Override
    //将数据库类型转换为java类型
    public Date getNullableResult(ResultSet resultSet, int i) throws SQLException {
    
    
        long aLong = resultSet.getLong(i);
        Date date = new Date(aLong);
        return date;
    }

    @Override
    //将数据库类型转换为java类型
    public Date getNullableResult(CallableStatement callableStatement, int i) throws SQLException {
    
    
        long aLong = callableStatement.getLong(i);
        Date date = new Date(aLong);
        return date;
    }
}

UserMapper接口

package com.ljx.mapper;

import com.ljx.domain.User;

import java.util.List;

public interface UserMapper {
    
    

    void save(User user);

    List<User> findAll();
}

resource：配置文件

com/ljx/mapper/User.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybbatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.ljx.mapper.UserMapper">
    <insert id="save" parameterType="user">
        insert into user01 values (#{id},#{username},#{password},#{birthday})
    </insert>
    <select id="findAll" resultType="user">
        select * from user01
    </select>

</mapper>

jdbc.properties

jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/test
jdbc.username=root
jdbc.password=asd.123

sqlMapConfig.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>

<!--    通过properties标签加载外部properties文件-->
    <properties resource="jdbc.properties"></properties>

<!--    定义别名-->
    <typeAliases>
        <typeAlias type="com.ljx.domain.User" alias="user"></typeAlias>
    </typeAliases>

<!--    注册类型处理器-->
    <typeHandlers>
        <typeHandler handler="com.ljx.handler.DateTypeHandler"/>
    </typeHandlers>

<!--    配置分页助手插件-->
    <plugins>
        <plugin interceptor="com.github.pagehelper.PageHelper">
            <property name="dialect" value="mysql"/>
        </plugin>
    </plugins>
<!--    数据源对象-->
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"></transactionManager>
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.driver}"/>
                <property name="url" value="${jdbc.url}"/>
                <property name="username" value="${jdbc.username}"/>
                <property name="password" value="${jdbc.password}"/>
            </dataSource>
        </environment>
    </environments>


<!--    加载映射文件-->
    <mappers>
        <mapper resource="com\ljx\mapper\User.xml"></mapper>
    </mappers>
</configuration>

pom.xml

<?xml version="1.0" encoding="UTF-8"?>

<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>org.example</groupId>
  <artifactId>mybatis_config</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>war</packaging>

  <name>mybatis_config Maven Webapp</name>
  <!-- FIXME change it to the project's website -->
  <url>http://www.example.com</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
  </properties>

  <dependencies>
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.23</version>
    </dependency>
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.5.6</version>
    </dependency>
    <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.17</version>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>com.github.jsqlparser</groupId>
      <artifactId>jsqlparser</artifactId>
      <version>0.9.1</version>
    </dependency>
    <dependency>
      <groupId>com.github.pagehelper</groupId>
      <artifactId>pagehelper</artifactId>
      <version>3.7.5</version>
    </dependency>
  </dependencies>
  
</project>