亲宝软件园·资讯

展开

mybatis 自定义日期类型转换器

Le`soleil 人气:1

前言

使用mybatis中的typeHandlers 实现自定义日期类型的转换器。
重点在2.2 handler中

一、resources

在这里插入图片描述

1.1 sqlMapConfig.xml

typeHandlers: 自定义的日期类型转换器:
(1)将日期类型转为long的长整型存入数据库中。
(2)将数据库中的bigint(本质对应java的long类型)转为date类型。environments:加载数据库mapper: 映射文件的位置

<?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>

    <typeHandlers>
        <typeHandler handler="com.mytest.handler.DateTypeHandler"></typeHandler>
    </typeHandlers>
    <environments default="dev">
        <environment id="dev">
            <transactionManager type="JDBC"></transactionManager>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/test"/>
                <property name="username" value="root"/>
                <property name="password" value="123456"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="com.mytest.mapper/UserMapper.xml"></mapper>
    </mappers>
</configuration>

1.2 log4j.properties

打印日志

### direct log messages to stdout ###
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n

### direct messages to file mylog.log ###
log4j.appender.file=org.apache.log4j.FileAppender
log4j.appender.file.File=c:/mylog.log
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n
### set log levels - for more verbose logging change 'info' to 'debug' ###
log4j.rootLogger=debug, stdout

1.3 userMapper.xml

1.findByid: 通过id查询插入元素

2.save: xml映射器mapper时,

useGeneratedKeys:值为true 并分别指定属性:
keyProperty: 对应的Java对象的主键属性
keyColumn: 对应的数据库记录主键字段

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.mytest.dao.UserMapper">
<!--    通过id查询插入元素-->

    <select id="findByid" parameterType="int" resultType="com.mytest.pojo.User">
        select * from sys_user where id=#{id}
    </select>

<!--    插入元素-->
    <insert id="save" parameterType="com.mytest.pojo.User" useGeneratedKeys="true" keyProperty="id" keyColumn="id">
        insert into sys_user(id,username,email,password,phoneNum,birthday) values(null,#{username},null,#{password},null,#{birthday})
    </insert>
</mapper>

二、java结构

在这里插入图片描述

2.1 dao

UserMapper

1.findByid: 使用id值查询User

2.save: 插入User到数据库中

package com.mytest.dao;

import com.mytest.pojo.User;
import java.util.List;
public interface UserMapper {
    
    User findByid(int id);
    public void save(User user);
}

2.2 handler

DateTypeHandler

  1. setNonNullParameter:将java类型 转换成 数据库需要的类型
  2. getNullableResult:将数据库中类型 转换成java类型
package com.mytest.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> {
    //将java类型 转换成 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);
    }
    //将数据库中类型 转换成java类型
    //String参数  要转换的字段名称
    //ResultSet 查询出的结果集
    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;
    public Date getNullableResult(ResultSet resultSet, int i) throws SQLException {
        long aLong = resultSet.getLong(i);
    public Date getNullableResult(CallableStatement callableStatement, int i) throws SQLException {
        long aLong = callableStatement.getLong(i);
}

2.3 pojo

package com.mytest.pojo;

import java.util.Date;
public class User {
    private Integer id;
    private String username;
    private String password;
    private Date birthday;
    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 +
                '}';
    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;
}

2.4 service

service没用进行实现,在本demo中只用于测试使用。
sqlSession.commit()用于mybatis的事务提交。mybatis的事务默认是不提交的,故在增删改中需要进行事务的提交,在mybatis中事务的提交方式一般有两种:
1 sqlSession.commit()
2 采用openSession(true),即可实现自动提交,无需调用commit()方法。

package com.mytest.service;

import com.mytest.dao.UserMapper;
import com.mytest.pojo.User;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import java.io.IOException;
import java.io.InputStream;
import java.util.Date;
import java.util.List;
public class ServiceTest {
    public static void main(String[] args) throws IOException {
        InputStream inputStream = Resources.getResourceAsStream("sqlMapConfig.xml");
        SqlSessionFactory sqlSessionFactory = (SqlSessionFactory) new SqlSessionFactoryBuilder().build(inputStream);
        //openSession为true则自动提交事务
        SqlSession sqlSession = sqlSessionFactory.openSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        User user = new User();
        //插入不需要设置id值
//        user.setId(5);
        user.setUsername("wangwu");
        user.setPassword("123");
        user.setBirthday(new Date());
        //会返回属性值
        mapper.save(user);
        Integer userId = user.getId();
        
        sqlSession.commit();
        User findUser = mapper.findByid(userId);
        System.out.println(findUser);
    }
}

三 数据表结构及测试

数据表结构

在这里插入图片描述

测试

在这里插入图片描述

加载全部内容

相关教程
猜你喜欢
用户评论