首页 / 技术问答 / Java问答列表 / 问答详情

Java 为什么Spring Boot项目无法为基于MySQL的CRUD应用程序找到从JPARepository接口扩展的ProductRepository

我是春靴的新手.我正在try 使用JPARepository和MySQL在Spring工具套件中实现一个简单的CRUD应用程序.当我try 作为Spring Boot App运行该项目时，收到以下错误.

误差率个

Field repo in com.project.rest.ProductServiceImpl required a bean of type 'com.project.repos.ProductRepository' that could not be found.

The injection point has the following annotations:
    - @org.springframework.beans.factory.annotation.Autowired(required=true)


Action:

Consider defining a bean of type 'com.project.repos.ProductRepository' in your configuration.

以下是项目 struct 图

enter image description here

以下是项目代码和配置.

build.gradle个

plugins {
    id 'java'
    id 'org.springframework.boot' version '3.2.1'
    id 'io.spring.dependency-management' version '1.1.4'
}

group = 'com.project.rest'
version = '0.0.1-SNAPSHOT'

java {
    sourceCompatibility = '17'
}

repositories {
    mavenCentral()
}

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-web'
    implementation 'mysql:mysql-connector-java:8.0.26'
    implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
    testImplementation 'org.springframework.boot:spring-boot-starter-test'
}

tasks.named('test') {
    useJUnitPlatform()
}

application.properties个

server.port=8000
server.servlet.context-path=/productcrud
spring.datasource.url=jdbc:mysql://localhost:3306/mydb
spring.datasource.username=root
spring.datasource.password=theCORRECTPassword

ProductCrudApplication.java个

package com.project.rest;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;


@SpringBootApplication
public class ProductCrudApplication {

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

}

Product.java个

package com.project.entities;

import jakarta.persistence.Entity;
import jakarta.persistence.Id;



@Entity
public class Product {
    
    @Id
    private int id;
    private String name;
    private String description;
    private int price;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getDescription() {
        return description;
    }
    public void setDescription(String description) {
        this.description = description;
    }
    public int getPrice() {
        return price;
    }
    public void setPrice(int price) {
        this.price = price;
    }
    
    

}

ProductRepository.java个

package com.project.repos;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;

import com.project.entities.Product;


@Repository
public interface ProductRepository extends JpaRepository<Product, Integer> {

}

ProductServiceImpl.java个

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.project.entities.Product;
import com.project.repos.ProductRepository;

@Service
public class ProductServiceImpl {
    
    @Autowired
    ProductRepository repo;

    
    public List<Product> getProducts() {
        // TODO Auto-generated method stub

        return (List<Product>)repo.findAll();
    }

    
    public Product getProduct(int id) {
        // TODO Auto-generated method stub
        return repo.findById(id).get();
    }

    
    public String createProduct(Product product) {
        // TODO Auto-generated method stub
        Product p=repo.save(product);
        if(p!=null) {
            return ("Product created with id "+p.getId());
        }
        return "误差率 creating";
    }

    
    public String updateProduct(Product product) {
        // TODO Auto-generated method stub
        Product p=repo.save(product);
        if(p!=null) {
            return ("Product created with id "+p.getId());
        }
        return "误差率 updating";
    }
}

ProductController.java个

package com.project.rest;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.PutMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.project.entities.Product;

@RestController
public class ProductController {
    
    @Autowired
    ProductServiceImpl productService;
    
    @GetMapping("/products")
    public List<Product> getProducts() {
        // TODO Auto-generated method stub
        return productService.getProducts();
    }

    @GetMapping("/product/{id}")
    public Product getProduct(@PathVariable("id") int id) {
        // TODO Auto-generated method stub
        return productService.getProduct(id);
    }

    @PostMapping("/create")
    public ResponseEntity<String> createProduct(@RequestBody Product product) {
        // TODO Auto-generated method stub
        return new ResponseEntity<String>(productService.createProduct(product),HttpStatus.OK);
    }

    @PutMapping("/update")
    public ResponseEntity<String> updateProduct(@RequestBody Product product) {
        // TODO Auto-generated method stub
        return new ResponseEntity<String>(productService.updateProduct(product),HttpStatus.OK);
    }
    

}

以下是解决该问题的try .

Attempt 1个

ProductCrudApplication.java

package com.project.rest;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;


@SpringBootApplication
@EnableJpaRepositories("com.project.repos") //added this
public class ProductCrudApplication {

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

}

误差率


org.springframework.beans.factory.UnsatisfiedDependencyException: 误差率 creating bean with name 'productController': Unsatisfied dependency expressed through field 'productService': 误差率 creating bean with name 'productServiceImpl': Unsatisfied dependency expressed through field 'repo': 误差率 creating bean with name 'productRepository' defined in com.project.repos.ProductRepository defined in @EnableJpaRepositories declared on ProductCrudApplication: Not a managed type: class com.project.entities.Product
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:787) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:767) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:145) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:508) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1418) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:598) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:521) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:325) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:323) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:975) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:960) ~[spring-context-6.1.2.jar:6.1.2]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:625) ~[spring-context-6.1.2.jar:6.1.2]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:146) ~[spring-boot-3.2.1.jar:3.2.1]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:762) ~[spring-boot-3.2.1.jar:3.2.1]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:464) ~[spring-boot-3.2.1.jar:3.2.1]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:334) ~[spring-boot-3.2.1.jar:3.2.1]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1358) ~[spring-boot-3.2.1.jar:3.2.1]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1347) ~[spring-boot-3.2.1.jar:3.2.1]
    at com.project.rest.ProductCrudApplication.main(ProductCrudApplication.java:14) ~[main/:na]
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: 误差率 creating bean with name 'productServiceImpl': Unsatisfied dependency expressed through field 'repo': 误差率 creating bean with name 'productRepository' defined in com.project.repos.ProductRepository defined in @EnableJpaRepositories declared on ProductCrudApplication: Not a managed type: class com.project.entities.Product
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:787) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:767) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:145) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:508) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1418) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:598) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:521) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:325) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:323) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:254) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1443) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1353) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:784) ~[spring-beans-6.1.2.jar:6.1.2]
    ... 20 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: 误差率 creating bean with name 'productRepository' defined in com.project.repos.ProductRepository defined in @EnableJpaRepositories declared on ProductCrudApplication: Not a managed type: class com.project.entities.Product
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1773) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:599) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:521) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:325) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:323) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:254) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1443) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1353) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:784) ~[spring-beans-6.1.2.jar:6.1.2]
    ... 34 common frames omitted
Caused by: java.lang.IllegalArgumentException: Not a managed type: class com.project.entities.Product
    at org.hibernate.metamodel.model.domain.internal.JpaMetamodelImpl.managedType(JpaMetamodelImpl.java:193) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.metamodel.model.domain.internal.MappingMetamodelImpl.managedType(MappingMetamodelImpl.java:468) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.metamodel.model.domain.internal.MappingMetamodelImpl.managedType(MappingMetamodelImpl.java:98) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.springframework.data.jpa.repository.support.JpaMetamodelEntityInformation.<init>(JpaMetamodelEntityInformation.java:82) ~[spring-data-jpa-3.2.1.jar:3.2.1]
    at org.springframework.data.jpa.repository.support.JpaEntityInformationSupport.getEntityInformation(JpaEntityInformationSupport.java:69) ~[spring-data-jpa-3.2.1.jar:3.2.1]
    at org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getEntityInformation(JpaRepositoryFactory.java:246) ~[spring-data-jpa-3.2.1.jar:3.2.1]
    at org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getTargetRepository(JpaRepositoryFactory.java:211) ~[spring-data-jpa-3.2.1.jar:3.2.1]
    at org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getTargetRepository(JpaRepositoryFactory.java:194) ~[spring-data-jpa-3.2.1.jar:3.2.1]
    at org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getTargetRepository(JpaRepositoryFactory.java:81) ~[spring-data-jpa-3.2.1.jar:3.2.1]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport.getRepository(RepositoryFactorySupport.java:317) ~[spring-data-commons-3.2.1.jar:3.2.1]
    at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.lambda$afterPropertiesSet$5(RepositoryFactoryBeanSupport.java:279) ~[spring-data-commons-3.2.1.jar:3.2.1]
    at org.springframework.data.util.Lazy.getNullable(Lazy.java:135) ~[spring-data-commons-3.2.1.jar:3.2.1]
    at org.springframework.data.util.Lazy.get(Lazy.java:113) ~[spring-data-commons-3.2.1.jar:3.2.1]
    at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.afterPropertiesSet(RepositoryFactoryBeanSupport.java:285) ~[spring-data-commons-3.2.1.jar:3.2.1]
    at org.springframework.data.jpa.repository.support.JpaRepositoryFactoryBean.afterPropertiesSet(JpaRepositoryFactoryBean.java:132) ~[spring-data-jpa-3.2.1.jar:3.2.1]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1820) ~[spring-beans-6.1.2.jar:6.1.2]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1769) ~[spring-beans-6.1.2.jar:6.1.2]
    ... 44 common frames omitted

Attempt 2个

@SpringBootApplication
@EnableJpaRepositories("com.project.repos") //added this
@ComponentScan({"com.project.entities","com.project.repos","com.project.rest"}) //added this
public class ProductCrudApplication {

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

}

误差率 - same as in Attempt 1

Attempt 3个

@SpringBootApplication
@ComponentScan({"com.project.entities","com.project.repos","com.project.rest"}) //added this
public class ProductCrudApplication {

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

}

误差率 - same as original one "Field repo in com.project.rest.ProductServiceImpl required a bean of type 'com.project.repos.ProductRepository' that could not be found."

我会请求善意的帮助.

推荐答案

默认情况下，Spring Boot自动扫描放置在与主应用程序类(@SpringBootApplication)相同的包或子包中的实体. 只要您的实体类使用@Entity进行注释，就不需要额外的配置.

目前，您的实体在包com.project.entities中，主应用程序类在包com.project.rest中.因此，您的实体不会被扫描.

最简单的修复方法是将您的主类移到包com.project

或者，如果您希望将实体放在与主应用程序类不同的包中，则可以使用@EntityScan注释. 将@EntityScan加到您的主应用程序类或专用配置类中，指定您的实体所在的基包(S).

Java相关问答推荐

Java在模块化jar文件中找不到类，但是javap可以

ittext pdf延迟签名，签名无效

Android Studio—java—在onBindViewHolder中，将断点和空白添加到BackclerView中

Spring Boot@Cachebale批注未按预期工作

在bash中将数组作为Java程序的参数传递

AssertJ Java：多条件断言

Java编译器抛出可能未正确初始化的错误？

try 判断可选参数是否为空时出现空类型安全警告

如何在 spring 数据的MongoDB派生查询方法中使用$EXISTS

如何将Pane的图像快照保存为BMP？

我可以在@Cacheable中使用枚举吗

项目react 堆中doOnComplete()和Subscribe()的第三个参数之间的差异

记录是类的语法糖吗？

Java Flux中的延迟增加

如何将RESTAssured'；S的Http标题转换为<；字符串、字符串和>的映射？

在Java中比较同一多维数组的两个不同的字符串元素

如何以事务方式向ibmmq发送消息

using case default on switch语句返回；预览特征切换中的模式匹配仅在源级别20及以上的情况下可用；

如何在 Android Studio 中删除 ImageView 和屏幕/父级边缘之间的额外空间？

有没有办法仅将 JComboBox 中的选定项目居中(因此保持组合框中的所有项目左对齐)

实用课程推荐
相关教程推荐
休闲君评测 |  TOOLFK工具网 |  古诗文网 |  良许Linux教程网 |  Python之禅 |  红色石头 |  入党申请书 | 

© 2020 Hi LearnFk 意见反馈 免责声明 关于我们 桂ICP备11002319号-3 友链&广告位+QQ: 1963612630