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目录前言一、resources1.1sqlMapConfig.xml1.2log4j.properties1.3userMapper.xml二、java结构2.1dao2.2hand
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
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>
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.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>
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);
}
DateTypeHandler
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);
}
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;
}
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);
}
}
数据表结构
测试
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本文标题: 使用 mybatis 自定义日期类型转换器的示例代码
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