交易何时提交(默认情况下)?

时间:2018-10-05 13:19:04

标签: spring-boot jpa transactions spring-data-jpa spring-transactions

我正在编写一个很小的spring boot应用程序,没有任何与事务相关的特殊属性。我的REST控制器在存储库上调用save(myEntity)

何时进行数据库事务处理?

会被承诺

  • save方法的一部分吗? (可能为时过早,以后可能会出现异常)
  • 我自己的代码完成后返回到Spring Boot代码吗?
  • 甚至以后,何时完成结果的序列化?
  • 还是这取决于数据库驱动程序?

示例代码dbtransaction/Application.java

package dbtransaction;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import javax.persistence.Entity;
import javax.persistence.Id;
import java.util.UUID;

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

@RestController
@RequestMapping("/thing")
class ThingRestController {

    private ThingRepository thingRepository;

    public ThingRestController(ThingRepository thingRepository) {
        this.thingRepository = thingRepository;
    }

    @RequestMapping(method = RequestMethod.GET)
    public Thing createNew() {
        return thingRepository.save(new Thing());
    }
}

@Repository
interface ThingRepository extends JpaRepository<Thing, String> {
}

@Entity
class Thing {
    @Id
    public UUID uuid = UUID.randomUUID();
}

示例pom 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>

    <artifactId>dbtransaction</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>pom</packaging>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.5.RELEASE</version>
    </parent>

    <properties>
        <java.version>11</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-rest</artifactId>
        </dependency>

        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <scope>runtime</scope>
        </dependency>

        <dependency>
            <groupId>org.javassist</groupId>
            <artifactId>javassist</artifactId>
            <version>3.23.1-GA</version>
        </dependency>
    </dependencies>

</project>

1 个答案:

答案 0 :(得分:1)

何时提交取决于您的交易范围。在您提供的代码示例中,您没有指定任何事务范围,因此它将默认为您的存储库方法。它将在您致电thingRepository.save之后提交。

请注意,JpaRepository的默认实现是SimpleJpaRepository,如果您查看该类,则会看到它用@Transactional注释了其save方法。因此,这成为您交易的默认边界。您可以通过在外部方法上指定@Transactional来轻松更改事务范围。