spring-boot - Spring boot cassandra 集成 @EnableCassandraRepositories 未生成 Cassandra 存储库的实现

Question

我正在尝试使用 spring-data-cassandra 将 cassandra 与 Spring boot 集成。

应用程序.java

package hello;

import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.SpringApplication;
import org.springframework.context.annotation.ComponentScan;

@ComponentScan
@EnableAutoConfiguration
public class Application {

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

CassandraConfiguration.java

package conf;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.cassandra.config.CassandraClusterFactoryBean;
import org.springframework.data.cassandra.config.java.AbstractCassandraConfiguration;
import org.springframework.data.cassandra.mapping.BasicCassandraMappingContext;
import org.springframework.data.cassandra.mapping.CassandraMappingContext;
import org.springframework.data.cassandra.repository.config.EnableCassandraRepositories;


@Configuration
@EnableCassandraRepositories("dao")
public class CassandraConfiguration extends AbstractCassandraConfiguration {

    @Bean
    @Override
    public CassandraClusterFactoryBean cluster() {
        CassandraClusterFactoryBean cluster = new CassandraClusterFactoryBean();
        cluster.setContactPoints("localhost");
        cluster.setPort(9042);
        return cluster;
    }

    @Override
    protected String getKeyspaceName() {
        return "mykeyspace";
    }

    @Bean
    @Override
    public CassandraMappingContext cassandraMapping() throws  ClassNotFoundException {
         return new BasicCassandraMappingContext();
    }

}

UserDao.java

package dao;

import hello.User;
import org.springframework.data.cassandra.repository.CassandraRepository;
import org.springframework.data.cassandra.repository.Query;

public interface UserDao extends CassandraRepository<User> {

    @Query("select * from users where fname = ?0")
    Iterable findByFname(String fname);
}

RestController.java

package hello;

import dao.UserDao; 
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;


    @RestController
    public class UserController {

    @Autowired
    UserDao userDao;


    @RequestMapping("/greeting")
    public Iterable<User> getInfo(@RequestParam(value="name", defaultValue="Hello") String name, @RequestParam(value="lname", defaultValue="World") String lname) {
        return userDao.findByFname(name) ;//new User(counter.incrementAndGet(),name, lname);
    }
}

用户.java

package hello;

import org.springframework.data.cassandra.mapping.Column;
import org.springframework.data.cassandra.mapping.PrimaryKey;
import org.springframework.data.cassandra.mapping.Table;

@Table
public class User {

    @PrimaryKey
    private final long id;
    @Column
    private final String fname;
    @Column
    private final String lname;

    public User(long id, String fname, String lname) {
        this.id = id;
        this.fname = fname;
        this.lname = lname;
    }

    public long getId() {
        return id;
    }

    public String getFname() {
        return fname;
    }

    public String getLname() {
        return lname;
    }

}

在幕后 @EnableCassandraConfiguration 应该创建 UserDao 接口(interface)的实现。但似乎由于某种原因它没有这样做。日志对于告诉我在这里犯的具体错误没有那么有用。为了寻求帮助，我将其发布在这里。

2015-02-11 12:10:58.424  INFO 7828 --- [           main] hello.Application                        : Starting Application on HOTCPC9941 with PID 7828 (C:\Users\prashant.tiwari\Documents\NetBeansProjects\DemoApp\target\classes started by prashant.tiwari in C:\Users\prashant.tiwari\Documents\NetBeansProjects\DemoApp)
2015-02-11 12:10:58.459  INFO 7828 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@4f5737ca: startup date [Wed Feb 11 12:10:58 GMT 2015]; root of context hierarchy
2015-02-11 12:10:59.141  INFO 7828 --- [           main] o.s.b.f.s.DefaultListableBeanFactory     : Overriding bean definition for bean 'beanNameViewResolver': replacing [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=org.springframework.boot.autoconfigure.web.ErrorMvcAutoConfiguration$WhitelabelErrorViewConfiguration; factoryMethodName=beanNameViewResolver; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [org/springframework/boot/autoconfigure/web/ErrorMvcAutoConfiguration$WhitelabelErrorViewConfiguration.class]] with [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration$WebMvcAutoConfigurationAdapter; factoryMethodName=beanNameViewResolver; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [org/springframework/boot/autoconfigure/web/WebMvcAutoConfiguration$WebMvcAutoConfigurationAdapter.class]]
2015-02-11 12:10:59.865  INFO 7828 --- [           main] .t.TomcatEmbeddedServletContainerFactory : Server initialized with port: 8080
2015-02-11 12:11:00.035  INFO 7828 --- [           main] o.apache.catalina.core.StandardService   : Starting service Tomcat
2015-02-11 12:11:00.036  INFO 7828 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/7.0.57
2015-02-11 12:11:00.127  INFO 7828 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2015-02-11 12:11:00.128  INFO 7828 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 1672 ms
2015-02-11 12:11:00.555  INFO 7828 --- [ost-startStop-1] o.s.b.c.e.ServletRegistrationBean        : Mapping servlet: 'dispatcherServlet' to [/]
2015-02-11 12:11:00.557  INFO 7828 --- [ost-startStop-1] o.s.b.c.embedded.FilterRegistrationBean  : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2015-02-11 12:11:00.682  WARN 7828 --- [           main] ationConfigEmbeddedWebApplicationContext : Exception encountered during context initialization - cancelling refresh attempt

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: dao.UserDao hello.UserController.userDao; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [dao.UserDao] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:301)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1186)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:298)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:706)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:762)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:109)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:691)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:320)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:952)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:941)
    at hello.Application.main(Application.java:12)

Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: dao.UserDao hello.UserController.userDao; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [dao.UserDao] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:522)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:298)
    ... 16 common frames omitted
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [dao.UserDao] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1118)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:967)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:862)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:494)
    ... 18 common frames omitted

Answer 1

似乎您的 Dao 类没有注册到上下文中。我想说它缺少像 @Repository 这样的适当注释。

此外，您的 Application 类位于 hello 包中，无需任何进一步配置，仅扫描其下面的组件。这就是为什么它找不到 CassandraConfiguration (位于 conf 中)。这也是不扫描 dao 包。