储存库中的Spring Boot自定义查询，错误为NullPointerException

时间：2018-07-06 07:12:35

标签： java mysql spring-boot

我正在使用spring boot来使用@query构建Web API，以根据问题的描述和类型从Question表中获取一个Question（数据库表）项。 存储库中的代码：

@Query(
        value = "select * from question q where q.description like %:desc% and q.question_type = :type",
        nativeQuery = true
    )
    public Optional<Question> findByDescAndTitle(@Param("desc") String desc,
                                                 @Param("type") String type);

代码我运行方法findByDescAndTitle：

/**
 * 
 */
package com.enmasseQuiz.runners;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.stereotype.Component;

import com.enmasseQuiz.models.Question;
import com.enmasseQuiz.repos.QuestionRepo;

/**
 * @author leoliu
 *
 */
@Component
public class QuizCommandRunner implements CommandLineRunner {

    @Autowired
    QuestionRepo questionRepo;

    @Override
    public void run(String... args) throws Exception {
        System.out.println("=== Available services: ");
        for (Question q: this.questionRepo.findAll()) {
            System.out.println(q);
        }

        System.out.println(this.questionRepo.findByDescAndTitle("MVP", "mcq"));
    }

}

但是当我尝试运行时，它总是给我NullPointerException错误：

java.lang.IllegalStateException: Failed to execute CommandLineRunner
        at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:800) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
        at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:781) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:335) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1255) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1243) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
        at com.enmasseQuiz.EnmasseQuizApplication.main(EnmasseQuizApplication.java:16) [main/:na]
Caused by: java.lang.NullPointerException: null
        at java.lang.String$CaseInsensitiveComparator.compare(String.java:1192) ~[na:1.8.0_111]
        at java.lang.String$CaseInsensitiveComparator.compare(String.java:1186) ~[na:1.8.0_111]
        at java.util.TreeMap.getEntryUsingComparator(TreeMap.java:376) ~[na:1.8.0_111]
        at java.util.TreeMap.getEntry(TreeMap.java:345) ~[na:1.8.0_111]
        at java.util.TreeMap.get(TreeMap.java:278) ~[na:1.8.0_111]
        at com.mysql.jdbc.ResultSetImpl.findColumn(ResultSetImpl.java:1054) ~[mysql-connector-java-5.1.46.jar:5.1.46]
        at com.mysql.jdbc.ResultSetImpl.getString(ResultSetImpl.java:5177) ~[mysql-connector-java-5.1.46.jar:5.1.46]
        at com.zaxxer.hikari.pool.HikariProxyResultSet.getString(HikariProxyResultSet.java) ~[HikariCP-2.7.9.jar:na]
        at org.hibernate.type.descriptor.sql.VarcharTypeDescriptor$2.doExtract(VarcharTypeDescriptor.java:62) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at org.hibernate.type.descriptor.sql.BasicExtractor.extract(BasicExtractor.java:47) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:261) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:257) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:253) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at org.hibernate.loader.Loader.getInstanceClass(Loader.java:1808) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at org.hibernate.loader.Loader.instanceNotYetLoaded(Loader.java:1633) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at org.hibernate.loader.Loader.getRow(Loader.java:1562) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:732) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at org.hibernate.loader.Loader.processResultSet(Loader.java:991) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at org.hibernate.loader.Loader.doQuery(Loader.java:949) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:341) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at org.hibernate.loader.Loader.doList(Loader.java:2692) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at org.hibernate.loader.Loader.doList(Loader.java:2675) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2507) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at org.hibernate.loader.Loader.list(Loader.java:2502) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at org.hibernate.loader.custom.CustomLoader.list(CustomLoader.java:335) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at org.hibernate.internal.SessionImpl.listCustomQuery(SessionImpl.java:2200) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at org.hibernate.internal.AbstractSharedSessionContract.list(AbstractSharedSessionContract.java:1016) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at org.hibernate.query.internal.NativeQueryImpl.doList(NativeQueryImpl.java:152) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at org.hibernate.query.internal.AbstractProducedQuery.list(AbstractProducedQuery.java:1414) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at org.hibernate.query.internal.AbstractProducedQuery.getSingleResult(AbstractProducedQuery.java:1463) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_111]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_111]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_111]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_111]
        at org.springframework.orm.jpa.SharedEntityManagerCreator$DeferredQueryInvocationHandler.invoke(SharedEntityManagerCreator.java:380) ~[spring-orm-5.0.7.RELEASE.jar:5.0.7.RELEASE]
        at com.sun.proxy.$Proxy110.getSingleResult(Unknown Source) ~[na:na]
        at org.springframework.data.jpa.repository.query.JpaQueryExecution$SingleEntityExecution.doExecute(JpaQueryExecution.java:214) ~[spring-data-jpa-2.0.8.RELEASE.jar:2.0.8.RELEASE]
        at org.springframework.data.jpa.repository.query.JpaQueryExecution.execute(JpaQueryExecution.java:91) ~[spring-data-jpa-2.0.8.RELEASE.jar:2.0.8.RELEASE]
        at org.springframework.data.jpa.repository.query.AbstractJpaQuery.doExecute(AbstractJpaQuery.java:136) ~[spring-data-jpa-2.0.8.RELEASE.jar:2.0.8.RELEASE]
        at org.springframework.data.jpa.repository.query.AbstractJpaQuery.execute(AbstractJpaQuery.java:125) ~[spring-data-jpa-2.0.8.RELEASE.jar:2.0.8.RELEASE]
        at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:590) ~[spring-data-commons-2.0.8.RELEASE.jar:2.0.8.RELEASE]
        at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:578) ~[spring-data-commons-2.0.8.RELEASE.jar:2.0.8.RELEASE]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.7.RELEASE.jar:5.0.7.RELEASE]
        at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:59) ~[spring-data-commons-2.0.8.RELEASE.jar:2.0.8.RELEASE]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.7.RELEASE.jar:5.0.7.RELEASE]
        at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:294) ~[spring-tx-5.0.7.RELEASE.jar:5.0.7.RELEASE]
        at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98) ~[spring-tx-5.0.7.RELEASE.jar:5.0.7.RELEASE]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.7.RELEASE.jar:5.0.7.RELEASE]
        at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139) ~[spring-tx-5.0.7.RELEASE.jar:5.0.7.RELEASE]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.7.RELEASE.jar:5.0.7.RELEASE]
        at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:135) ~[spring-data-jpa-2.0.8.RELEASE.jar:2.0.8.RELEASE]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.7.RELEASE.jar:5.0.7.RELEASE]
        at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) ~[spring-aop-5.0.7.RELEASE.jar:5.0.7.RELEASE]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.7.RELEASE.jar:5.0.7.RELEASE]
        at org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:61) ~[spring-data-commons-2.0.8.RELEASE.jar:2.0.8.RELEASE]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.7.RELEASE.jar:5.0.7.RELEASE]
        at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212) ~[spring-aop-5.0.7.RELEASE.jar:5.0.7.RELEASE]
        at com.sun.proxy.$Proxy102.findByDescAndTitle(Unknown Source) ~[na:na]
        at com.enmasseQuiz.runners.QuizCommandRunner.run(QuizCommandRunner.java:30) ~[main/:na]
        at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:797) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
        ... 5 common frames omitted

我正在将Java 8和Spring boot 2与Gradle一起使用。搜索几天而不是几天似乎会提到此错误：

  

CaseInsensitiveComparator

EnmasseQuizApplication.java：

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

@SpringBootApplication
@Configuration
@ComponentScan
@EnableAutoConfiguration
public class EnmasseQuizApplication {

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

数据库表很简单，如下所示： database schema

我对Spring启动框架还很陌生，并且不知道如何调试此问题。如果有人可以提供帮助，我们将不胜感激。

0 个答案:

没有答案
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