SpringBoot中Autowired注入BugRepository失败，无法找到对应Bean

问题描述 #

执行java -jar启动SpringBoot应用时触发如下错误：

Field bugRepository in be.tquality.demospringdb.BugController required a bean of type 'be.tquality.demospringdb.BugRepository' that could not be found.

IDE中代码关联正常，但打包运行时Spring无法自动装配BugRepository。

涉及代码片段 #

BugRepository.java

package be.tquality.demospringdb;

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface BugRepository extends JpaRepository<Bug, Long> {

}

BugController.java

package be.tquality.demospringdb;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class BugController {

    @Autowired
    private BugRepository bugRepository;

    @GetMapping(value = "bug/findall")
    public List<Bug> findAll(){
        return bugRepository.findAll();
    }
}

Bug.java（实体类）

package be.tquality.demospringdb;

import lombok.Data;

import javax.persistence.*;
import java.io.Serializable;

@Entity
@Table(name = "BUG")
@Data
public class Bug implements Serializable {

    private static final long serialVersionUID = -2343243243242432341L;

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int id;

    @Column(name = "TESTCASEID")
    private int testcaseid;

    @Column(name = "TESTSTEPID")
    private int teststepid;

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

    @Column(name = "DESCRIPTION")
    private String description;

    @Column(name = "STATUS")
    private int status;

    @Column(name = "ASSIGNEE")
    private int assignee;

    @Column(name = "PROJECTID")
    private int projectid;

    @Column(name = "EXPECTEDRESULT")
    private String expectedresult;

    @Column(name = "ACTUALRESULT")
    private String actualresult;

    public Bug(){}

    public Bug(int testcaseid, int teststepid, String title, String description, int status,int assignee,int projectid,
               String expectedresult,String actualresult) {
        this.testcaseid = testcaseid;
        this.teststepid = teststepid;
        this.title = title;
        this.description = description;
        this.status = status;
        this.assignee = assignee;
        this.projectid = projectid;
        this.expectedresult = expectedresult;
        this.actualresult = actualresult;
    }
}

DemospringdbApplication.java（启动类）

package be.tquality.demospringdb;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class DemospringdbApplication {

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

解决方案 #

1. 修复Repository泛型类型不匹配问题 #

BugRepository继承JpaRepository<Bug, Long>，但实体类Bug的主键id是int类型，泛型ID类型必须与实体主键类型一致。修改Repository代码：

@Repository
public interface BugRepository extends JpaRepository<Bug, Integer> {
}

2. 显式指定JPA扫描范围（可选） #

虽然@SpringBootApplication默认扫描启动类所在包，但显式配置扫描范围可以避免特殊场景下的扫描遗漏。修改启动类：

package be.tquality.demospringdb;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.domain.EntityScan;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;

@SpringBootApplication
@EnableJpaRepositories(basePackages = "be.tquality.demospringdb")
@EntityScan(basePackages = "be.tquality.demospringdb")
public class DemospringdbApplication {
    public static void main(String[] args) {
        SpringApplication.run(DemospringdbApplication.class, args);
    }
}

3. 确认Spring Data JPA依赖已正确引入 #

检查pom.xml（Maven）或build.gradle（Gradle）是否包含JPA starter依赖：

• Maven配置：

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

• Gradle配置：

implementation 'org.springframework.boot:spring-boot-starter-data-jpa'

4. 重新打包应用 #

执行清理打包命令，确保所有类都被正确打包到jar中：

• Maven：mvn clean package
• Gradle：gradle clean build

内容的提问来源于stack exchange，提问作者steve