LocalDateTime與mysql日期類型的交互（基於mybatis）

衆所周知，在實體Entity裏面，能夠使用Java.sql.Date、java.sql.Timestamp、java.util.Date來映射到數據庫的date、timestamp、datetime等字段，可是，java.sql.Date、java.sql.Timestamp、java.util.Date這些類都很差用，不少方法都過期了。

Java8裏面新出來了一些API，LocalDate、LocalTime、LocalDateTime 很是好用，默認的狀況下，在mybatis裏面不支持java8的時間、日期。直接使用，會報以下錯誤

Caused by: java.lang.IllegalStateException: No typehandler found for property createTime  
    at org.apache.ibatis.mapping.ResultMapping$Builder.validate(ResultMapping.java:151)  
    at org.apache.ibatis.mapping.ResultMapping$Builder.build(ResultMapping.java:140)  
    at org.apache.ibatis.builder.MapperBuilderAssistant.buildResultMapping(MapperBuilderAssistant.java:382)  
    at org.apache.ibatis.builder.xml.XMLMapperBuilder.buildResultMappingFromContext(XMLMapperBuilder.java:378)  
    at org.apache.ibatis.builder.xml.XMLMapperBuilder.resultMapElement(XMLMapperBuilder.java:280)  
    at org.apache.ibatis.builder.xml.XMLMapperBuilder.resultMapElement(XMLMapperBuilder.java:252)  
    at org.apache.ibatis.builder.xml.XMLMapperBuilder.resultMapElements(XMLMapperBuilder.java:244)  
    at org.apache.ibatis.builder.xml.XMLMapperBuilder.configurationElement(XMLMapperBuilder.java:116)  
    ... 81 common frames omitted  

 導入依賴

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>tk.mybatis</groupId>
            <artifactId>mapper-spring-boot-starter</artifactId>
            <version>2.0.2</version>
        </dependency>
        <!-- mybatis數據庫字段類型映射，此處是重點 -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-typehandlers-jsr310</artifactId>
            <version>1.0.1</version>
        </dependency>
        <!-- MYSQL驅動包 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

屬性配置

spring.datasource.url=jdbc:mysql://localhost:3306/dev?useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull&allowMultiQueries=true&useSSL=false
spring.datasource.username=root
spring.datasource.password=123456
# 若是想看到mybatis日誌須要作以下配置
logging.level.com.carry=DEBUG
######### Mybatis 自身配置 ##########
mybatis.mapper-locations=classpath:com/carry/mapper/*Mapper.xml
mybatis.type-aliases-package=com.carry.dto
# 駝峯命名規範 如：數據庫字段是  order_id 那麼 實體字段就要寫成 orderId
mybatis.configuration.map-underscore-to-camel-case=true
######### 通用Mapper ##########
# 主鍵自增回寫方法,默認值MYSQL,詳細說明請看文檔
mapper.identity=MYSQL
mapper.mappers=tk.mybatis.mapper.common.Mapper
# 設置 insert 和 update 中，是否判斷字符串類型!=''
mapper.not-empty=true
# 枚舉按簡單類型處理
mapper.enum-as-simple-type=true

建表SQL

CREATE TABLE `user` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `create_date` date DEFAULT NULL,
  `create_time` datetime DEFAULT NULL,
  PRIMARY KEY (`id`)
)

實體類

package com.carry.dto;
import java.io.Serializable;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
import javax.persistence.GeneratedValue;
 import javax.persistence.GenerationType;
 import javax.persistence.Id;
import com.fasterxml.jackson.annotation.JsonFormat;
public class User implements Serializable{

}</span><span style="color: #0000ff;">private</span> <span style="color: #0000ff;">static</span> <span style="color: #0000ff;">final</span> <span style="color: #0000ff;">long</span> serialVersionUID = -108907189034815108L<span style="color: #000000;">;

@Id
@GeneratedValue(strategy </span>=<span style="color: #000000;"> GenerationType.IDENTITY)
</span><span style="color: #0000ff;">private</span><span style="color: #000000;"> Long id;
@JsonFormat(pattern </span>= "yyyy-MM-dd"<span style="color: #000000;">)
</span><span style="color: #0000ff;">private</span><span style="color: #000000;"> LocalDate createDate;
@JsonFormat(pattern </span>= "yyyy-MM-dd HH:mm:ss"<span style="color: #000000;">)
</span><span style="color: #0000ff;">private</span><span style="color: #000000;"> LocalDateTime createTime;

</span><span style="color: #0000ff;">public</span><span style="color: #000000;"> Long getId() {
    </span><span style="color: #0000ff;">return</span><span style="color: #000000;"> id;
}

</span><span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> setId(Long id) {
    </span><span style="color: #0000ff;">this</span>.id =<span style="color: #000000;"> id;
}

</span><span style="color: #0000ff;">public</span><span style="color: #000000;"> LocalDate getCreateDate() {
    </span><span style="color: #0000ff;">return</span><span style="color: #000000;"> createDate;
}

</span><span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> setCreateDate(LocalDate createDate) {
    </span><span style="color: #0000ff;">this</span>.createDate =<span style="color: #000000;"> createDate;
}

</span><span style="color: #0000ff;">public</span><span style="color: #000000;"> LocalDateTime getCreateTime() {
    </span><span style="color: #0000ff;">return</span><span style="color: #000000;"> createTime;
}

</span><span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> setCreateTime(LocalDateTime createTime) {
    </span><span style="color: #0000ff;">this</span>.createTime =<span style="color: #000000;"> createTime;
}

Mapper類

package com.carry.mapper;
import com.carry.dto.User;
import tk.mybatis.mapper.common.Mapper;
public interface UserMapper extends Mapper<User> {
}

啓動類

package com.carry;
import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
import tk.mybatis.spring.annotation.MapperScan;
@SpringBootApplication
 @MapperScan(basePackages = "com.carry.mapper")
 public class SpringBootDateMysqlApplication {

public static void main(String[] args) {
        SpringApplication.run(SpringBootDateMysqlApplication.class, args);
    }
}

測試

package com.carry;
import java.time.LocalDate;
 import java.time.LocalDateTime;
import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.test.context.junit4.SpringRunner;
import com.carry.dto.User;
 import com.carry.mapper.UserMapper;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
@RunWith(SpringRunner.class)
 @SpringBootTest
 public class SpringBootDateMysqlApplicationTests {

}@Autowired
</span><span style="color: #0000ff;">private</span><span style="color: #000000;"> UserMapper mapper;

@Autowired
</span><span style="color: #0000ff;">private</span><span style="color: #000000;"> ObjectMapper objectMapper;

@Test
</span><span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> insert() {
    User user </span>= <span style="color: #0000ff;">new</span><span style="color: #000000;"> User();
    user.setCreateDate(LocalDate.now());
    user.setCreateTime(LocalDateTime.now());
    mapper.insertSelective(user);
}

@Test
</span><span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> query() {
    mapper.selectAll().stream().forEach(e </span>-&gt;<span style="color: #000000;"> {
        </span><span style="color: #0000ff;">try</span><span style="color: #000000;"> {
            System.out.println(objectMapper.writeValueAsString(e));
        } </span><span style="color: #0000ff;">catch</span><span style="color: #000000;"> (JsonProcessingException ex) {
            ex.printStackTrace();
        }
    });
}

前後執行測試方法 insert 和 query，無錯誤說明測試經過

SpringBootDateMysql

原文地址：https://blog.csdn.net/kingboyworld/article/details/75808108