创建bean时出现Spring Data JPA错误

Question

person.java

package com.test.business;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "person")
public class Person {

  @Id
  @Column(name = "id")
  private int id;
  @Column(name = "name")
  private String name;

  public Person(){
  }

  public Person(int id, String name) {
    this.id = id;
    this.name = name;
  }

//getters and setters
}

PersonRepository.java

package com.test.repository;

import com.test.business.Person;
import org.springframework.data.repository.CrudRepository;

public interface PersonRepository extends CrudRepository<Person, Long> {

}

PersonService.java

package com.test.service;

import com.test.business.Person;
import com.test.repository.PersonRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class PersonService{

  @Autowired
  private PersonRepository personRepository;

  public void addNewPerson(){
    personRepository.save(new Person(2, "Test2"));
  }
}

PersonController.java

package com.test.controller;

import com.test.service.PersonService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
public class PersonController {

  @Autowired
  private PersonService personService;

  @GetMapping(value="/")
  @ResponseBody
  public String printWelcome() {
    personService.addNewPerson();
    return "home";
  }

MyWebInitializer.java

package com.test.config;

import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

public class MyWebInitializer extends
    AbstractAnnotationConfigDispatcherServletInitializer {

  @Override
  protected Class<?>[] getRootConfigClasses() {
    return new Class[] { RootConfig.class };
  }

  @Override
  protected Class<?>[] getServletConfigClasses() {
    return new Class[] { WebConfig.class };
  }

  @Override
  protected String[] getServletMappings() {
    return new String[] { "/" };
  }

}

WebConfig.java

package com.test.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
import org.springframework.web.servlet.view.JstlView;

@EnableWebMvc
@Configuration
@ComponentScan({ "com.test.controller" })
public class WebConfig implements WebMvcConfigurer {

  @Override
  public void addResourceHandlers(ResourceHandlerRegistry registry) {
    registry.addResourceHandler("/resources/**")
        .addResourceLocations("/resources/");
  }

  @Bean
  public InternalResourceViewResolver viewResolver() {
    InternalResourceViewResolver viewResolver
        = new InternalResourceViewResolver();
    viewResolver.setViewClass(JstlView.class);
    viewResolver.setPrefix("/WEB-INF/views/jsp/");
    viewResolver.setSuffix(".jsp");
    return viewResolver;
  }

}

rootconfig.java

package com.test.config;

import java.util.Properties;
import javax.sql.DataSource;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.orm.jpa.vendor.Database;
import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@Configuration
@EnableJpaRepositories( basePackages = {"com.test.repository"})
@EnableTransactionManagement
@ComponentScan(basePackages = {"com.test.service", "com.test.repository", "com.test.controller", "com.test.business"})
public class RootConfig {

  @Autowired
  private DataSource dataSource;

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

    return dataSource;
  }

  @Bean
  public LocalContainerEntityManagerFactoryBean entityManagerFactory() {

    HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
    vendorAdapter.setDatabase(Database.POSTGRESQL);
    vendorAdapter.setGenerateDdl(true);
    vendorAdapter.setShowSql(true);

    LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();
    factory.setJpaVendorAdapter(vendorAdapter);
    factory.setPackagesToScan(getClass().getPackage().getName());
    factory.setDataSource(dataSource());
    factory.setJpaProperties(jpaProperties());

    return factory;
  }

  private Properties jpaProperties() {
    Properties properties = new Properties();

    properties.put("hibernate.dialect", "org.hibernate.dialect.PostgreSQLDialect");
    properties.put("hibernate.show_sql", "true");
    return properties;
  }
  @Bean
  public PlatformTransactionManager transactionManager() {

    JpaTransactionManager txManager = new JpaTransactionManager();
    txManager.setEntityManagerFactory(entityManagerFactory().getObject());
    return txManager;
  }

}

Build.Gradle

plugins {
    id 'java'
}

apply plugin: 'war'

group 'testApp'
version '1.0-SNAPSHOT'

sourceCompatibility = 1.8

repositories {
    mavenCentral()
}

dependencies {
    compile 'org.apache.tomcat:tomcat-catalina:9.0.10'
    compile 'org.springframework.boot:spring-boot-starter-data-jpa:2.0.3.RELEASE'
    compile 'org.hibernate:hibernate-core:5.3.2.Final'
    compile 'org.springframework.data:spring-data-jpa:2.0.9.RELEASE'
    compile 'org.postgresql:postgresql:42.2.3'
    compile 'org.springframework:spring-webmvc:5.0.7.RELEASE'
    compile 'org.hibernate:hibernate-entitymanager:5.3.3.Final'
    compile 'javax.xml.bind:jaxb-api:2.3.0'
}

构建此项目时没有错误，但当我尝试运行此应用程序时，控制台显示错误：

错误org.springframework.web.Context.contextloader-上下文初始化失败org.springframework.beans.factory.UnsatisfiedDependencyException：创建名为“Person Service”的bean时出错：通过字段“Person Repository”表示的不满足的依赖关系；嵌套异常为org.springframework.beans.factory.BeanCreationException：创建名为“Person Repository”的bean时出错：调用init方法失败；嵌套异常为java.lang.IllegalArgumentException：不是托管类型：class com.test.business.Person

（...）

原因：org.springframework.beans.factory.BeanCreationException：创建名为“Person Repository”的bean时出错：调用init方法失败；嵌套异常为java.lang.IllegalArgumentException：不是托管类型：class com.test.business.Person

（...）

原因：java.lang.IllegalArgumentException：不是托管类型：class com.test.business.Person

这是为什么？为什么不能创建personService bean？我在Person.java中有@Entity，包括autowired，RootConfig包含@ComponentScan

@ComponentScan(basePackages = {"com.test.service", "com.test.repository", "com.test.controller", "com.test.business"})

你能给我一些建议来解决我的问题吗？

Answer 1

在上下文初始化时，spring无法将您的实体类标识为有效实体。要使它们有效,请尝试下列操作之一：

1. 将Factory.SetPackageStoscan（getClass().GetPackage().GetName())；更改为Factory.SetPackageStoscan（“com.test.business”）；。否则com.test.config包将用于实体扫描。
2. 尝试删除factory.setPackageStoscan(getClass().getPackage().getName())；并将@EntityScan（“com.test.business”）放在RootConfig.java
之上

另请参阅@EntityScan和@ComponentScan之间的区别