Spring数据中的自定义方法实现失败，出现“未找到属性”错误

Question

我正在尝试使用Spring Boot 1.5.9在Spring数据存储库中实现自定义方法。释放我创建了存储库：

package com.example.springdatademo;

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

@Repository
interface MyEntityRepository extends JpaRepository<MyEntity, String>, CustomMyEntityRepository {

}

提供了自定义存储库：

package com.example.springdatademo;

interface CustomMyEntityRepository {
    MyEntity myCustomFindQuery();
}

以及实施：

package com.example.springdatademo;

import org.springframework.stereotype.Component;

    @Component
    class CustomMyEntityRepositoryImpl implements CustomMyEntityRepository {


        @Override
        public MyEntity myCustomFindQuery() {
            System.out.println("hello from custom query implementation");
            return null;
        }
    }

此外，我还提供了一个调用：

package com.example.springdatademo;

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

@EntityScan
@EnableJpaRepositories
@SpringBootApplication
public class SpringDataDemoApplication {

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

    @Bean
    public CommandLineRunner run(MyEntityRepository repository) {
        return (args) -> {
            final MyEntity myEntity1 = repository.myCustomFindQuery();
            repository.save(new MyEntity(1, "fieldTwo"));
            for (MyEntity myEntity : repository.findAll()) {
                System.out.println(myEntity);
            }
        };
    }

}

pom。xml只是由spring初始值设定项生成的普通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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.RELEASE</version>
<!--        <version>2.1.9.RELEASE</version>-->
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>spring-data-demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>spring-data-demo</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

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

        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

在Spring Boot 1.5.9上运行项目时。RELEASE我在容器创建时遇到了一个问题：起因：java.lang.IllegalArgumentExctive：未能创建查询方法公共摘要com.example.springdatademo.MyEntitycom.example.springdatademo.CustomMyEntityRepository.myCustomFindQuery（）！没有找到用于类型MyEntity的属性myCustomFindQuery！

将Spring Boot版本更改为2.1.9。发布效果很好，给了我预期的结果。

我在spring-data-jpa-1.11.9中找不到任何提示。发布文档

Answer 1

如果你想运行当前代码，那么你需要一个@NamedQuery，如果你想运行hql，或者如果你想在实体类中运行名为MyEntity.myCustomFindQuery的本机查询@NamedNativeQuery

@NamedQuery(name="MyEntity.myCustomFindQuery", 
query="SELECT 1 as a, 'a' as b from MyEntity")

或

  @NamedNativeQuery(name="MyEntity.myCustomFindQuery", 
    query="SELECT 1 as a, 'a' as b", resultSetMapping="mapmyCustomFindQuery")

@SqlResultSetMapping(name = "mapmyCustomFindQuery", classes = {
        @ConstructorResult(targetClass = MyEntity.class, columns = {
                @ColumnResult(name = "a"), @ColumnResult(name = "b")

        })
})

或者，您可以将这两个存储库分开（这意味着MyEntityRepository不应该扩展MyEntityRepositoryCustom）

在这种情况下，您的应用程序类将如下所示

@Autowired 
    MyEntityRepository repository;

    @Autowired
    MyEntityRepositoryCustom entityRepositoryCustom;



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

    @Bean
    public CommandLineRunner run() {
        return (args) -> {
            final MyEntity myEntity1 = entityRepositoryCustom.myCustomFindQuery();
            repository.save(new MyEntity(1, "fieldTwo"));
            for (MyEntity myEntity : repository.findAll()) {
                System.out.println(myEntity);
            }
        };
    }

Answer 2

我刚刚检查了你的代码，并且能够修复它。我就是这么做的

将MyEntityRepositoryCustomImpl重命名为MyEntityRepositoryImpl

正如我在评论中告诉你的，cutom存储库应该命名为MyEntityRepositoryCustom（我想你已经这么做了）

命名约定是这里的关键。Impl类应命名为