spring jpa hibernate=当前线程没有实际事务可用的EntityManager-无法可靠地处理“persist”调用

Question

尝试使用EntityManager时出错

当前线程没有实际事务可用的EntityManager-无法可靠地处理'persist'调用

我使用Spring（不是boot）、jpa和hibernate

有人能帮我吗？

实体课程

package com;

import javax.persistence.*;

@Entity
@Table(name="courses")
public class Course {

    private int id;

    @Column(name = "title")
    private String title;

    @Column(name = "length")
    private int length;

    @Column(name = "description")
    public String description;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name="id")
    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    @Column(name="title")
    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    @Column(name="length")
    public int getLength() {
        return length;
    }

    public void setLength(int length) {
        this.length = length;
    }

    @Column(name="description")
    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }
}

Spring配置类

@Configuration
@ComponentScan(basePackages = "com")
@EnableTransactionManagement
public class AppConfig {


    @Bean
    public DataSource dataSource() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName("org.postgresql.Driver");
        dataSource.setUrl("jdbc:postgresql://127.0.0.1:5432/lib33");
        dataSource.setUsername("postgres");
        dataSource.setPassword("root");
        return dataSource;
    }


    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
        LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
        em.setDataSource(dataSource());
        em.setPackagesToScan(new String[]{"com"});

        JpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        em.setJpaVendorAdapter(vendorAdapter);
        em.setJpaProperties(hibernateProperties());

        return em;
    }


    @Bean
    public PlatformTransactionManager txManager(EntityManagerFactory emf) {
        JpaTransactionManager txManager = new JpaTransactionManager();
        txManager.setEntityManagerFactory(emf);
        txManager.setDataSource(dataSource());
        return txManager;
    }



    private Properties hibernateProperties() {
        Properties props = new Properties();
        props.setProperty("hibernate.dialect", "org.hibernate.dialect.PostgreSQL94Dialect");
        props.setProperty("hibernate.hbm2ddl.auto", "update");
        props.setProperty("hibernate.globally_quoted_identifiers", "true");
        props.setProperty("hibernate.show_sql", "true");
        return props;
    }
}

在我得到的地方测试“刀”

import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;


@Repository
@Transactional
public class MyTest3 {

    @PersistenceContext
    private EntityManager entityManager;

    void MyTest2(){
        System.out.println("hello");
        Course course2 = new Course();
        course2.setDescription("test desc");
        course2.setTitle("test title");

       entityManager.persist(course2);  // <--- ERROR

     //   System.out.println(entityManager.find(Course.class, 1).description);
    }

}

使用find complete for error命令行

和我的主班

public class Main {


    public static void main(String[] args) throws SQLException {

        System.out.println("hello");

        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(AppConfig.class);

        MyTest3 myTest3 = context.getBean(MyTest3.class);
        myTest3.MyTest2();

    }
}

哦，我的朋友。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>test9</groupId>
  <artifactId>test9</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>war</packaging>

  <name>test9 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>1.7</maven.compiler.source>
    <maven.compiler.target>1.7</maven.compiler.target>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>


    <!-- https://mvnrepository.com/artifact/org.springframework/spring-context -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>5.2.5.RELEASE</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.postgresql/postgresql -->
    <dependency>
      <groupId>org.postgresql</groupId>
      <artifactId>postgresql</artifactId>
      <version>42.2.13</version>
    </dependency>


    <!-- https://mvnrepository.com/artifact/org.springframework/spring-tx -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>5.2.5.RELEASE</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.springframework/spring-orm -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-orm</artifactId>
      <version>5.2.5.RELEASE</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/javax/javaee-api -->
    <dependency>
      <groupId>javax</groupId>
      <artifactId>javaee-api</artifactId>
      <version>8.0</version>
      <scope>provided</scope>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-core -->
    <dependency>
      <groupId>org.hibernate</groupId>
      <artifactId>hibernate-core</artifactId>
      <version>5.4.13.Final</version>
    </dependency>

    <dependency>
      <groupId>org.hibernate.javax.persistence</groupId>
      <artifactId>hibernate-jpa-2.1-api</artifactId>
      <version>1.0.2.Final</version>
    </dependency>

    <dependency>
      <groupId>org.hibernate</groupId>
      <artifactId>hibernate-entitymanager</artifactId>
      <version>5.1.13.Final</version>
    </dependency>

  </dependencies>

  <build>
    <finalName>test9</finalName>
    <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
      <plugins>
        <plugin>
          <artifactId>maven-clean-plugin</artifactId>
          <version>3.1.0</version>
        </plugin>
        <!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_war_packaging -->
        <plugin>
          <artifactId>maven-resources-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.8.0</version>
        </plugin>
        <plugin>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>2.22.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-war-plugin</artifactId>
          <version>3.2.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-install-plugin</artifactId>
          <version>2.5.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-deploy-plugin</artifactId>
          <version>2.8.2</version>
        </plugin>
      </plugins>
    </pluginManagement>
  </build>
</project>

我在类和方法上使用了@Transactional，结果没有改变

请帮帮我，我已经做了所有的选择。

Answer 1

Spring使用Spring AOP（面向方面编程）来实现事务，这意味着您必须在MyTest2（）方法上使用公共访问级别，以便AOP代理可以拦截它。否则，就像你从来没有注释你的方法与@Transactional