问题描述
我很难让测试通过 Pivotal 的 spring-boot 1.4 版本的示例项目 来自他们的示例，其中显示了 spring-data-jpa 在其 JPQL 中使用 unannotated 命名参数
I'm having a hard time getting the tests to pass on Pivotal's example project for the spring-boot 1.4 release from their examples which shows spring-data-jpa using unannotated named parameters in its JPQL
例如
来自 example.springdata.jpa.simple.SimpleUserRepository
@Query("select u from User u where u.firstname = :firstname")
List<User> findByFirstname(String firstname);
NB 它没有使用 @Param 注释
这不在我的机器上运行.我在这里得到了详细的异常，从标题中可以不言自明.
This doesn't run on my machine. I get the exception detailed here, which is self-explanatory from the title.
参数绑定的名称不能为null或为空！对于命名参数，您需要在 Java 版本上使用 @Param 查询方法参数
所以我必须这样做:
@Query("select u from User u where u.firstname = ?1")
List<User> findByFirstname(String firstname);
或者这个:
@Query("select u from User u where u.firstname = :firstname")
List<User> findByFirstname(@Param("firstname") String firstname);
我正在使用什么:
- 操作系统-Win7
- Java - 1.8.0_112
- IDE - Intellij IDEA 2016.2
- JPA 版本-JPA v2.0
- 配置-spring-boot-1.4.1
那么我设置示例的方式有问题吗?
So have I got something wrong the way I set up the examples?
spring-data-jpa 是否曾经包含一些很酷的功能来自动检测后来由于某种原因被删除的参数名称?
Did spring-data-jpa include some cool feature at one time to auto-detect param names that for some reason got removed later?
org.springframework.dao.InvalidDataAccessApiUsageException: Name for parameter binding must not be null or empty! For named parameters you need to use @Param for query method parameters on Java versions < 8.; nested exception is java.lang.IllegalArgumentException: Name for parameter binding must not be null or empty! For named parameters you need to use @Param for query method parameters on Java versions < 8.
at org.springframework.orm.jpa.EntityManagerFactoryUtils.convertJpaAccessExceptionIfPossible(EntityManagerFactoryUtils.java:384)
at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:246)
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.translateExceptionIfPossible(AbstractEntityManagerFactoryBean.java:491)
at org.springframework.dao.support.ChainedPersistenceExceptionTranslator.translateExceptionIfPossible(ChainedPersistenceExceptionTranslator.java:59)
at org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:213)
at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:147)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:133)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)
at com.sun.proxy.$Proxy75.findByFirstnameOrLastname(Unknown Source)
at example.springdata.jpa.simple.SimpleUserRepositoryTests.findByFirstnameOrLastname(SimpleUserRepositoryTests.java:86)
====================================================================================================================
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)
at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)
at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:252)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:117)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:42)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:262)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:84)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
推荐答案
默认情况下，接口不保留参数名称信息——在没有 Java 版本中，即使没有设置 debug 标志.然而，Java 8 添加了一项功能，可以通过需要显式设置的新 -parameters 编译器标志来保留所有类型的参数信息.
By default, interfaces do not retain parameter name information — in no Java version, even not with the debug flag set. Java 8 however added a feature to enable the retention of parameter information for all types through a new -parameters compiler flag that needs to be set explicitly.
参见示例 在 Spring Data 示例存储库中.
See an example of this in the Spring Data examples repository.
这篇关于为什么即使在 Java 8 上也没有 Spring Data 存储库方法参数名称?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！