如何在使用 Spring Boot 时使用 Rest Service &春季数据 Jpa [英] How to use Rest Service while using Spring Boot & Spring Data Jpa

问题描述

我正在使用 spring 数据 jpa 开发用于休息服务的 spring 启动应用程序.我跟着老师看了很多答案，但我无法修复我的休息服务.

Im working on a spring boot application for rest service with using spring data jpa. I followed instructors and read much answers but I couldn't fix my rest service.

这里是application.class

package tr.kasim.Application;

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


@SpringBootApplication
@EnableJpaRepositories("tr.kasim.Dao")
@EntityScan("tr.kasim.Model")
@ComponentScan({"tr.kasim.Service", "tr.kasim.Application" })
public class Application {

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

}

这里是 `restcontroller.class

Here is `restcontroller.class

package tr.kasim.Controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import tr.kasim.Service.PersonelService;
import tr.kasim.Model.Personel;


@RestController
public class STRestController {

@Autowired
public PersonelService personelService;

@RequestMapping(value = "/api/personels", method = RequestMethod.GET)
public ResponseEntity<List<Personel>> getPersonels(){
    List<Personel> personels = personelService.findAll();
    return ResponseEntity.ok().body(personels);
}

}

`

这里是 Service.class`

Here is Service.class`

package tr.kasim.Service;

 import java.util.List;

import tr.kasim.Model.Personel;

public interface PersonelService {

List<Personel> findAll();
}

`

这里是 ServiceImplemention.class

Here is ServiceImplemantion.class

package tr.kasim.Service;

import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import tr.kasim.Dao.PersonelDao;
import tr.kasim.Model.Personel;

@Service
public class PersonelServiceImpl implements PersonelService {

@Autowired
private PersonelDao personelDao;

@Override
@Transactional
public List<Personel> findAll() {

    return personelDao.findAll();
}

}

这里是 Dao.class

Here is Dao.class

    package tr.kasim.Dao;

import java.util.List;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;
import tr.kasim.Model.Personel;

@Repository
public interface PersonelDao extends JpaRepository<Personel, Long> {

List<Personel> findAll();
}

最后是我的 application.properties

Lastly here is my application.properties

#MySql Connection
spring.datasource.url=jdbc:mysql://localhost:3306/exampleproject?verifyServerCertificate=false&useSSL=true
spring.datasource.username=root
spring.datasource.password=*******
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

#Jpa/Hibernate
spring.jpa.show-sql = true
spring.jpa.hibernate.ddl-auto = update
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5Dialect

#Logging
logging.file=staffTracking.log
logging.level.org.springframework.web=debug

我不确定 componentScan.当我阅读答案时，我发现有人提到了它，但我尝试了，但仍然一无所获.请告诉我我失败的地方.最好的问候.

Im not sure about componentScan. When I read answers I discovered someone mentioned about it but I tried and I got still nothing. Please show me where I failed. Best Regards.

我更新了 Application.class，现在我可以部署项目，但休息服务仍然无法工作.

I updated Application.class, now I can deploying project but rest service not working still.

推荐答案

您如何尝试 ComponentScan?这里的问题似乎是你的包结构是这样的:

How did you try ComponentScan? The issue here seems that you have a package structure like this:

tr.kasim.Application
  - Application.java
tr.kasim.Service
  - PersonelService.java
  - PersonelServiceImpl.java
tr.kasim.Dao
 - PersonelDao.java

现在，mainClass 位于 tr.kasim.Application 中，它将扫描该包内的 bean 定义(或 tr.kasim.Application).所以，

Now since, the mainClass is in tr.kasim.Application it would scan for bean definitions inside that package (or a sub-package in tr.kasim.Application). So,

• 要么将 mainClass 移出到像 tr.kasim 这样的父包，要么

• either you move the mainClass out to a parent-package like tr.kasim, or

使用 @ComponentScan({ "tr.kasim.Dao", "tr.kasim.Service", "tr.kasim.Application" }) 等等.

-- 更新--

根据目前的讨论，我建议采用第一个选项，因为这样可以减少手动启用实体、存储库等扫描的工作.

Based on the discussion so far, I'd suggest taking the first option as that reduces the effort to manually enable scan for entity, repository, etc.

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