java - 如何在简单的 Spring Boot 应用程序中 Autowiring 扩展 CrudRepository 的存储库？

在较高的层面上 - 我正在尝试将 Spring Data JPA 与现有的 Spring Boot 应用程序一起使用。我读过https://docs.spring.io/spring-data/jpa/docs/current/reference/html/#repositories但似乎找不到我要找的东西。

我尝试扩展“Accessing Data with JPA ”演示并遇到此错误。以下内容与演示代码之间的一些差异:

使用 Autowired 使用我的主 Spring Boot jar (JpaDemoApplication.java) 中的存储库
我在示例中没有使用 CommandLineRunner，而是使用 @Scheduled 注释

org.springframework.beans.NotReadablePropertyException: Invalid property 'id' of bean class [java.lang.String]: Could not find field for property during fallback access!
    at org.springframework.data.util.DirectFieldAccessFallbackBeanWrapper.getPropertyValue(DirectFieldAccessFallbackBeanWrapper.java:58) ~[spring-data-commons-2.2.1.RELEASE.jar:2.2.1.RELEASE]
    at org.springframework.data.jpa.repository.support.JpaMetamodelEntityInformation.getId(JpaMetamodelEntityInformation.java:153) ~[spring-data-jpa-2.2.1.RELEASE.jar:2.2.1.RELEASE]
    at org.springframework.data.repository.core.support.AbstractEntityInformation.isNew(AbstractEntityInformation.java:42) ~[spring-data-commons-2.2.1.RELEASE.jar:2.2.1.RELEASE]
    at org.springframework.data.jpa.repository.support.JpaMetamodelEntityInformation.isNew(JpaMetamodelEntityInformation.java:237) ~[spring-data-jpa-2.2.1.RELEASE.jar:2.2.1.RELEASE]
    at org.springframework.data.jpa.repository.support.SimpleJpaRepository.save(SimpleJpaRepository.java:553) ~[spring-data-jpa-2.2.1.RELEASE.jar:2.2.1.RELEASE]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:567) ~[na:na]
    at org.springframework.data.repository.core.support.RepositoryComposition$RepositoryFragments.invoke(RepositoryComposition.java:371) ~[spring-data-commons-2.2.1.RELEASE.jar:2.2.1.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryComposition.invoke(RepositoryComposition.java:204) ~[spring-data-commons-2.2.1.RELEASE.jar:2.2.1.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$ImplementationMethodExecutionInterceptor.invoke(RepositoryFactorySupport.java:657) ~[spring-data-commons-2.2.1.RELEASE.jar:2.2.1.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:621) ~[spring-data-commons-2.2.1.RELEASE.jar:2.2.1.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:605) ~[spring-data-commons-2.2.1.RELEASE.jar:2.2.1.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:366) ~[spring-tx-5.2.1.RELEASE.jar:5.2.1.RELEASE]
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:99) ~[spring-tx-5.2.1.RELEASE.jar:5.2.1.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139) ~[spring-tx-5.2.1.RELEASE.jar:5.2.1.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
    at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:178) ~[spring-data-jpa-2.2.1.RELEASE.jar:2.2.1.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:93) ~[spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212) ~[spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
    at com.sun.proxy.$Proxy67.save(Unknown Source) ~[na:na]
    at com.regchecker.jpademo.JpaDemoApplication.run(JpaDemoApplication.java:22) ~[classes/:na]

项目.java:

package com.demo.jpademo;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;


@Entity
public class Item {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    private String value;

    /**
     * @return the id
     */
    public Long getId() {
        return id;
    }

    /**
     * @param id the id to set
     */
    public void setId(Long id) {
        this.id = id;
    }

    /**
     * @return the value
     */
    public String getValue() {
        return value;
    }

    /**
     * @param value the value to set
     */
    public void setValue(String value) {
        this.value = value;
    }

    protected Item() {
    }

    public Item(String value) {
        this.value = value;

    }

    @Override
    public String toString() {
        return "Value: " + value;
    }

}

ItemRepository.java

package com.demo.jpademo;

import org.springframework.data.repository.CrudRepository;

public interface ItemRepository extends CrudRepository<Item, Long> {

    void save (String value);

}

JpaDemoApplication.java

package com.demo.jpademo;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.Scheduled;

@EnableScheduling
@SpringBootApplication
public class JpaDemoApplication {

    @Autowired
    ItemRepository itemrepo;

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

    @Scheduled(fixedRate=100000)
    public void run() {
        itemrepo.save("ABC");
        System.out.println(itemrepo.count());
    }

}

pom.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>2.2.1.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.demo.jpademo</groupId>
    <artifactId>jpa-demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>jpa-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>net.sourceforge.htmlunit</groupId>
            <artifactId>htmlunit</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

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

</project>

最佳答案

改变

@Repository
public interface ItemRepository extends CrudRepository<Item, Long> {
    // void save (String value);
}

和

@EnableScheduling
@SpringBootApplication
public class JpaDemoApplication {

    @Autowired
    ItemRepository itemrepo;

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

    @Scheduled(fixedRate=100000)
    public void run() {
        Item item = new Item();
        item.setValue("ABC");
        itemrepo.save(item); // Item instance, not String
        System.out.println(itemrepo.count());
    }

}

参见save方法文档。

关于java - 如何在简单的 Spring Boot 应用程序中 Autowiring 扩展 CrudRepository 的存储库？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/58830063/

java - 如何在简单的 Spring Boot 应用程序中 Autowiring 扩展 CrudRepository 的存储库？

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