Question

我是Spring框架的新手。我刚刚开始学习以下各种指南（http://spring.io/guides），并且我正在尝试完成有关网络服务的完整教程（http://spring.io/guides/tutorials/bookmarks/）。

我完全停留在JPA数据源定义上，因为我收到以下错误

Exception in thread "main" org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'init' defined in main.Application: Unsatisfied dependency expressed through constructor argument with index 0 of type [bookmarks.AccountRepository]: : No qualifying bean of type [bookmarks.AccountRepository] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [bookmarks.AccountRepository] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:749)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:464)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1111)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1006)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:504)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:303)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:299)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:762)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:757)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480)
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:691)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:321)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:961)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:950)
    at main.Application.main(Application.java:41)
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [bookmarks.AccountRepository] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1308)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1054)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:949)
    at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:813)
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:741)
    ... 18 more

我的主要Application类是以下

@Configuration
@ComponentScan
@EnableAutoConfiguration
public class Application {

    @Bean
    public CommandLineRunner init(AccountRepository accountRepository,
            BookmarkRepository bookmarkRepository) {
        System.out.println("Bean!");
        return (evt) -> Arrays.asList(
                "jhoeller,dsyer,pwebb,ogierke,rwinch,mfisher,mpollack,jlong".split(","))
                .forEach(
                        a -> {
                            Account account = accountRepository.save(new Account(a,
                                    "password"));
                            bookmarkRepository.save(new Bookmark(account,
                                    "http://bookmark.com/1/" + a, "A description"));
                            bookmarkRepository.save(new Bookmark(account,
                                    "http://bookmark.com/2/" + a, "A description"));
                        });
    }

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

我的pom.xml是

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.test</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1</version>
    <packaging>jar</packaging>

    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.2.1.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <start-class>demo.DemoApplication</start-class>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
        </dependency>
        <dependency>
            <groupId>javax.inject</groupId>
            <artifactId>javax.inject</artifactId>
            <version>1</version>
        </dependency>
    </dependencies>

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

</project>

我理解依赖注入框架没有找到AccountRepository接口的任何实现，看起来像

public interface AccountRepository extends JpaRepository<Account, Long> {
    Optional<Account> findByUsername(String username);
}

但是框架应该提供正确的实施＆＃34;对于JpaRepository。这是我不理解的部分。

任何帮助都会受到赞赏，特别是有一个指针可以深入研究这个框架。

由于

更新将@EnableJpaRepositories（＆＃34;书签＆＃34;）添加到Application类，解决了bean解析问题。但现在我明白了引起：java.lang.IllegalArgumentException：不是托管类型：class bookmarks.Account

我的帐户实体类是

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

import com.fasterxml.jackson.annotation.JsonIgnore;

@Entity
public class Account {

    @JsonIgnore
    public String password;
    public String username;
    @OneToMany(mappedBy="Account") 
    private Set<Bookmark> bookmarks = new HashSet<>();
    @Id @GeneratedValue 
    private Long id;

    public Account(String name, String password) {
        this.username = name;
        this.password = password;
    }

    Account() { } // jpa only

    // getters and setters
}

Answer 1

要使框架选择JpaRepository，您需要在配置中启用它 - 添加

@EnableJpaRepositories("your.package.with.jpa.repositories")

在@Configuration文件中。

<强> UPD

这里是jpa存储库的示例配置：

@Bean
public DataSource dataSource(){
    // configure your datasource
}

@Bean
public LocalContainerEntityManagerFactoryBean entityManagerFactory(DataSource dataSource) {
    LocalContainerEntityManagerFactoryBean emfb = new LocalContainerEntityManagerFactoryBean();
    emfb.setDataSource(dataSource);
    emfb.setPackagesToScan("your.package.with.model"); 
    emfb.setJpaVendorAdapter(jpaVendorAdapter());
    emfb.setJpaPropertyMap(jpaPropertiesMap()); 
    return emfb;
}

@Bean 
public JpaVendorAdapter jpaVendorAdapter() {
    return new HibernateJpaVendorAdapter();
}

@Bean
public PlatformTransactionManager transactionManager(EntityManagerFactory emf) {
    JpaTransactionManager transactionManager = new JpaTransactionManager();
    transactionManager.setEntityManagerFactory(emf);
    return transactionManager;
}

public Map<String, ?> jpaPropertiesMap() {
    Properties properties = new Properties();
    properties.setProperty("hibernate.dialect", "org.hibernate.dialect.H2Dialect"); // assumption based on your pom-file
    properties.setProperty("hibernate.hbm2ddl.auto", "..."); // you need to google for appropriate option
    return properties;
}

Answer 2

解决问题的最终（工作）配置如下（仅遵循文档http://spring.io/guides/tutorials/bookmarks/）。

解决方案是添加

<dependency>
  <groupId>com.h2database</groupId>
  <artifactId>h2</artifactId>
</dependency>

在pom.xml中，并更改

@OneToMany(mappedBy = "account")
private Set<Bookmark> bookmarks = new HashSet<>();

在Account类中（错误是：mappedBy =＆＃34; Account＆＃34;，大写字母......）。

以下完整代码：

的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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.test</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>MyRestService</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.2.1.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <start-class>demo.MyRestServiceApplication</start-class>
        <java.version>1.8</java.version>
    </properties>

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

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

</project>

帐户类

package bookmarks;

import java.util.HashSet;
import java.util.Set;

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

import com.fasterxml.jackson.annotation.JsonIgnore;

@Entity
public class Account {

    @OneToMany(mappedBy = "account")
    private Set<Bookmark> bookmarks = new HashSet<>();

    @Id
    @GeneratedValue
    private Long id;

    public Set<Bookmark> getBookmarks() {
        return bookmarks;
    }

    public Long getId() {
        return id;
    }

    public String getPassword() {
        return password;
    }

    public String getUsername() {
        return username;
    }

    @JsonIgnore
    public String password;
    public String username;

    public Account(String name, String password) {
        this.username = name;
        this.password = password;
    }

    Account() { // jpa only
    }
}

申请类

@Configuration
@ComponentScan
@EnableAutoConfiguration
public class Application {
    @Bean
    CommandLineRunner init(AccountRepository accountRepository,
            BookmarkRepository bookmarkRepository) {
        return (evt) -> Arrays.asList(
                "jhoeller,dsyer,pwebb,ogierke,rwinch,mfisher,mpollack,jlong".split(","))
                .forEach(
                        a -> {
                            Account account = accountRepository.save(new Account(a,
                                    "password"));
                            bookmarkRepository.save(new Bookmark(account,
                                    "http://bookmark.com/1/" + a, "A description"));
                            bookmarkRepository.save(new Bookmark(account,
                                    "http://bookmark.com/2/" + a, "A description"));
                        });
    }

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

Spring Data Repository - 没有限定bean注入

2 个答案: