首页 > 技术文章 > Springboot 之JPA查询报错

cncoding 2019-06-11 17:09 原文

在 CatDao中添加自定义查询方法后,启动报错

  1 2019-06-11 11:06:13.874  INFO 14700 --- [  restartedMain] org.hibernate.Version                    : HHH000412: Hibernate Core {5.3.7.Final}
  2 2019-06-11 11:06:13.890  INFO 14700 --- [  restartedMain] org.hibernate.cfg.Environment            : HHH000206: hibernate.properties not found
  3 2019-06-11 11:06:16.270  INFO 14700 --- [  restartedMain] o.hibernate.annotations.common.Version   : HCANN000001: Hibernate Commons Annotations {5.0.4.Final}
  4 2019-06-11 11:06:17.403  INFO 14700 --- [  restartedMain] org.hibernate.dialect.Dialect            : HHH000400: Using dialect: org.hibernate.dialect.MySQL5InnoDBDialect
  5 2019-06-11 11:06:23.144  INFO 14700 --- [  restartedMain] j.LocalContainerEntityManagerFactoryBean : Initialized JPA EntityManagerFactory for persistence unit 'default'
  6 2019-06-11 11:06:23.318  INFO 14700 --- [  restartedMain] o.s.b.d.a.OptionalLiveReloadServer       : LiveReload server is running on port 35729
  7 2019-06-11 11:06:25.815  WARN 14700 --- [  restartedMain] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'catController': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'catService': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'catDao': Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: Failed to create query for method public abstract java.util.List com.demo.dao.CatDao.findByCatName(java.lang.String)! Unable to locate Attribute  with the the given name [catName] on this ManagedType [com.demo.bean.Cat]
  8 2019-06-11 11:06:25.816  INFO 14700 --- [  restartedMain] j.LocalContainerEntityManagerFactoryBean : Closing JPA EntityManagerFactory for persistence unit 'default'
  9 2019-06-11 11:06:25.842  INFO 14700 --- [  restartedMain] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Shutdown initiated...
 10 2019-06-11 11:06:25.855  INFO 14700 --- [  restartedMain] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Shutdown completed.
 11 2019-06-11 11:06:25.858  INFO 14700 --- [  restartedMain] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
 12 2019-06-11 11:06:26.021  INFO 14700 --- [  restartedMain] ConditionEvaluationReportLoggingListener : 
 13 
 14 Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
 15 2019-06-11 11:06:26.228 ERROR 14700 --- [  restartedMain] o.s.boot.SpringApplication               : Application run failed
 16 
 17 org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'catController': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'catService': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'catDao': Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: Failed to create query for method public abstract java.util.List com.demo.dao.CatDao.findByCatName(java.lang.String)! Unable to locate Attribute  with the the given name [catName] on this ManagedType [com.demo.bean.Cat]
 18     at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessProperties(CommonAnnotationBeanPostProcessor.java:324) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 19     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1395) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 20     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:592) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 21     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 22     at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 23     at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 24     at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 25     at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 26     at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:849) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 27     at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:877) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 28     at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 29     at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142) ~[spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
 30     at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775) [spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
 31     at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) [spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
 32     at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) [spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
 33     at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) [spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
 34     at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) [spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
 35     at com.SpringBootHelloApplication.main(SpringBootHelloApplication.java:16) [classes/:na]
 36     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_121]
 37     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_121]
 38     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_121]
 39     at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_121]
 40     at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.1.3.RELEASE.jar:2.1.3.RELEASE]
 41 Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'catService': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'catDao': Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: Failed to create query for method public abstract java.util.List com.demo.dao.CatDao.findByCatName(java.lang.String)! Unable to locate Attribute  with the the given name [catName] on this ManagedType [com.demo.bean.Cat]
 42     at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessProperties(CommonAnnotationBeanPostProcessor.java:324) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 43     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1395) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 44     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:592) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 45     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 46     at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 47     at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 48     at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 49     at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:204) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 50     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.resolveBeanByName(AbstractAutowireCapableBeanFactory.java:452) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 51     at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.autowireResource(CommonAnnotationBeanPostProcessor.java:526) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 52     at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.getResource(CommonAnnotationBeanPostProcessor.java:496) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 53     at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor$ResourceElement.getResourceToInject(CommonAnnotationBeanPostProcessor.java:636) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 54     at org.springframework.beans.factory.annotation.InjectionMetadata$InjectedElement.inject(InjectionMetadata.java:180) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 55     at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 56     at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessProperties(CommonAnnotationBeanPostProcessor.java:321) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 57     ... 22 common frames omitted
 58 Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'catDao': Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: Failed to create query for method public abstract java.util.List com.demo.dao.CatDao.findByCatName(java.lang.String)! Unable to locate Attribute  with the the given name [catName] on this ManagedType [com.demo.bean.Cat]
 59     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1762) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 60     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 61     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 62     at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 63     at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 64     at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 65     at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 66     at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:277) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 67     at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1247) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 68     at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1167) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 69     at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.autowireResource(CommonAnnotationBeanPostProcessor.java:520) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 70     at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.getResource(CommonAnnotationBeanPostProcessor.java:496) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 71     at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor$ResourceElement.getResourceToInject(CommonAnnotationBeanPostProcessor.java:636) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 72     at org.springframework.beans.factory.annotation.InjectionMetadata$InjectedElement.inject(InjectionMetadata.java:180) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 73     at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 74     at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessProperties(CommonAnnotationBeanPostProcessor.java:321) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
 75     ... 36 common frames omitted
 76 Caused by: java.lang.IllegalArgumentException: Failed to create query for method public abstract java.util.List com.demo.dao.CatDao.findByCatName(java.lang.String)! Unable to locate Attribute  with the the given name [catName] on this ManagedType [com.demo.bean.Cat]
 77     at org.springframework.data.jpa.repository.query.PartTreeJpaQuery.<init>(PartTreeJpaQuery.java:82) ~[spring-data-jpa-2.1.5.RELEASE.jar:2.1.5.RELEASE]
 78     at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$CreateQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:103) ~[spring-data-jpa-2.1.5.RELEASE.jar:2.1.5.RELEASE]
 79     at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$CreateIfNotFoundQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:208) ~[spring-data-jpa-2.1.5.RELEASE.jar:2.1.5.RELEASE]
 80     at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$AbstractQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:79) ~[spring-data-jpa-2.1.5.RELEASE.jar:2.1.5.RELEASE]
 81     at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.lookupQuery(RepositoryFactorySupport.java:566) ~[spring-data-commons-2.1.5.RELEASE.jar:2.1.5.RELEASE]
 82     at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.lambda$mapMethodsToQuery$1(RepositoryFactorySupport.java:559) ~[spring-data-commons-2.1.5.RELEASE.jar:2.1.5.RELEASE]
 83     at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193) ~[na:1.8.0_121]
 84     at java.util.Iterator.forEachRemaining(Iterator.java:116) ~[na:1.8.0_121]
 85     at java.util.Collections$UnmodifiableCollection$1.forEachRemaining(Collections.java:1049) ~[na:1.8.0_121]
 86     at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801) ~[na:1.8.0_121]
 87     at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481) ~[na:1.8.0_121]
 88     at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471) ~[na:1.8.0_121]
 89     at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708) ~[na:1.8.0_121]
 90     at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[na:1.8.0_121]
 91     at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499) ~[na:1.8.0_121]
 92     at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.mapMethodsToQuery(RepositoryFactorySupport.java:561) ~[spring-data-commons-2.1.5.RELEASE.jar:2.1.5.RELEASE]
 93     at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.lambda$new$0(RepositoryFactorySupport.java:551) ~[spring-data-commons-2.1.5.RELEASE.jar:2.1.5.RELEASE]
 94     at java.util.Optional.map(Optional.java:215) ~[na:1.8.0_121]
 95     at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.<init>(RepositoryFactorySupport.java:551) ~[spring-data-commons-2.1.5.RELEASE.jar:2.1.5.RELEASE]
 96     at org.springframework.data.repository.core.support.RepositoryFactorySupport.getRepository(RepositoryFactorySupport.java:324) ~[spring-data-commons-2.1.5.RELEASE.jar:2.1.5.RELEASE]
 97     at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.lambda$afterPropertiesSet$5(RepositoryFactoryBeanSupport.java:297) ~[spring-data-commons-2.1.5.RELEASE.jar:2.1.5.RELEASE]
 98     at org.springframework.data.util.Lazy.getNullable(Lazy.java:211) ~[spring-data-commons-2.1.5.RELEASE.jar:2.1.5.RELEASE]
 99     at org.springframework.data.util.Lazy.get(Lazy.java:94) ~[spring-data-commons-2.1.5.RELEASE.jar:2.1.5.RELEASE]
100     at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.afterPropertiesSet(RepositoryFactoryBeanSupport.java:300) ~[spring-data-commons-2.1.5.RELEASE.jar:2.1.5.RELEASE]
101     at org.springframework.data.jpa.repository.support.JpaRepositoryFactoryBean.afterPropertiesSet(JpaRepositoryFactoryBean.java:119) ~[spring-data-jpa-2.1.5.RELEASE.jar:2.1.5.RELEASE]
102     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1821) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
103     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1758) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
104     ... 51 common frames omitted
105 Caused by: java.lang.IllegalArgumentException: Unable to locate Attribute  with the the given name [catName] on this ManagedType [com.demo.bean.Cat]
106     at org.hibernate.metamodel.internal.AbstractManagedType.checkNotNull(AbstractManagedType.java:128) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
107     at org.hibernate.metamodel.internal.AbstractManagedType.getAttribute(AbstractManagedType.java:113) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
108     at org.springframework.data.jpa.repository.query.QueryUtils.toExpressionRecursively(QueryUtils.java:593) ~[spring-data-jpa-2.1.5.RELEASE.jar:2.1.5.RELEASE]
109     at org.springframework.data.jpa.repository.query.QueryUtils.toExpressionRecursively(QueryUtils.java:577) ~[spring-data-jpa-2.1.5.RELEASE.jar:2.1.5.RELEASE]
110     at org.springframework.data.jpa.repository.query.JpaQueryCreator$PredicateBuilder.getTypedPath(JpaQueryCreator.java:379) ~[spring-data-jpa-2.1.5.RELEASE.jar:2.1.5.RELEASE]
111     at org.springframework.data.jpa.repository.query.JpaQueryCreator$PredicateBuilder.build(JpaQueryCreator.java:302) ~[spring-data-jpa-2.1.5.RELEASE.jar:2.1.5.RELEASE]
112     at org.springframework.data.jpa.repository.query.JpaQueryCreator.toPredicate(JpaQueryCreator.java:207) ~[spring-data-jpa-2.1.5.RELEASE.jar:2.1.5.RELEASE]
113     at org.springframework.data.jpa.repository.query.JpaQueryCreator.create(JpaQueryCreator.java:120) ~[spring-data-jpa-2.1.5.RELEASE.jar:2.1.5.RELEASE]
114     at org.springframework.data.jpa.repository.query.JpaQueryCreator.create(JpaQueryCreator.java:57) ~[spring-data-jpa-2.1.5.RELEASE.jar:2.1.5.RELEASE]
115     at org.springframework.data.repository.query.parser.AbstractQueryCreator.createCriteria(AbstractQueryCreator.java:119) ~[spring-data-commons-2.1.5.RELEASE.jar:2.1.5.RELEASE]
116     at org.springframework.data.repository.query.parser.AbstractQueryCreator.createQuery(AbstractQueryCreator.java:95) ~[spring-data-commons-2.1.5.RELEASE.jar:2.1.5.RELEASE]
117     at org.springframework.data.repository.query.parser.AbstractQueryCreator.createQuery(AbstractQueryCreator.java:81) ~[spring-data-commons-2.1.5.RELEASE.jar:2.1.5.RELEASE]
118     at org.springframework.data.jpa.repository.query.PartTreeJpaQuery$QueryPreparer.<init>(PartTreeJpaQuery.java:145) ~[spring-data-jpa-2.1.5.RELEASE.jar:2.1.5.RELEASE]
119     at org.springframework.data.jpa.repository.query.PartTreeJpaQuery$CountQueryPreparer.<init>(PartTreeJpaQuery.java:268) ~[spring-data-jpa-2.1.5.RELEASE.jar:2.1.5.RELEASE]
120     at org.springframework.data.jpa.repository.query.PartTreeJpaQuery.<init>(PartTreeJpaQuery.java:77) ~[spring-data-jpa-2.1.5.RELEASE.jar:2.1.5.RELEASE]
121     ... 77 common frames omitted
122 
123 
124 Process finished with exit code 0
View Code

 

 

1.controller层

@RestController
@RequestMapping("/cat")
public class CatController {
@Resource
    private CatService catService;
@GetMapping(value = "/findByCatName")
    public List<Cat> findByCatName(String catName){
        return catService.findByCatName(catName);
    }
}

2.service层

@Service
public class CatService {
    @Resource
    private CatDao catRepository;

public List<Cat> findByCatName(String catName){
        return catRepository.findByCatName(catName);
    }
}

 

3.dao层

public interface CatDao extends JpaRepository<Cat,Integer> {
 //根据名称查询
    List<Cat> findByCatName(String catName);
}

这样看着代码是没什么问题,而且之前在启动项目的时候,我可以通过代码生成数据库表了,所以就很自然的认为,实体是没有问题的;

但是在网上查了很多资料都是说dao层的字段名称和实体的不一致的问题,所以我就把注意力放在dao层上面去查问题,就这样查了好久,依然觉得代码没问题(很无奈啊....)

后来实在没有办法了就又去检查实体字段名称的定义,终于找到问题了,是因为字段的定义不符合规范,虽然之前已经可以通过实体生成表结构,但是在使用查询的时候,不知道为

什么还是注入不了(这个目前还没有搞清楚),最后把正确的实体贴出来,以来警醒自己吧

之前定义的变量名称是:CatAge/CatName

@Entity
public class Cat {
 @Id @GeneratedValue(strategy = GenerationType.AUTO)
    private int id ;//主键

    private String catName;//姓名

    private int catAge; //年龄

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getCatName() {
        return catName;
    }

    public void setCatName(String catName) {
        this.catName = catName;
    }

    public int getCatAge() {
        return catAge;
    }

    public void setCatAge(int catAge) {
        this.catAge = catAge;
    }
}

 

总结:

这次的错误主要是在创建实体的时候,变量的命名不规范造成的,所以简单总结下java的常用的几个命名规则:

1.包:所有包的命名必须采用小写英文字母;

2.类:采用驼峰命名法,类名的首字母必须采用大写的形式,如果类名为多个单词组合的话,那么每个字母的首字母必须采用大写,eg:CatDao.java;

3. 方法:采用驼峰命名法,首字母以小写开头,每个单词首字母大写(第一个单词除外);

4.变量:首字母以小写开头,每个单词首字母大写(第一个单词除外);

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