【发布时间】：2017-06-06 15:54:16
【问题描述】：
嘿，我是 spring 的新手，我正在尝试做一个程序来处理来自数据库的一堆记录并对它们做一些事情。基本上获取处于某种状态的所有记录，在操作系统中运行一个命令（每条记录一个），更改这些记录中的某些内容。
我认为理想的工具是使用 spring 的批处理服务支持。我已经将想要读取的记录映射到 JPA bean (Schedule)，并且我有 CrudRepository (ScheduleRepository)，所以我认为将所有内容连接在一起会很容易，尽管我不知道如何。
我尝试按照batch service guide 进行一些修改以读取来自 JPA 的输入。但是当我尝试运行时，当 spring 尝试实例化 JpaPagingItemReader 时，我得到了 NullPointerException。
我将尝试附上我认为与问题最相关的代码：
@Configuration
@EnableBatchProcessing
public class BatchConfiguration {
//@Autowired
//public ScheduleRepository repository;
@Autowired
public JobBuilderFactory jobBuilderFactory;
@Autowired
public StepBuilderFactory stepBuilderFactory;
@Bean
public Job synchronizeProcess(JobCompletionNotificationListener listener) {
return jobBuilderFactory.get("synchronizeProcess")
.incrementer(new RunIdIncrementer())
.listener(listener)
.flow(step1())
.end()
.build();
}
private Step step1() {
return stepBuilderFactory.get("step1")
.<Schedule, Schedule> chunk(10)
.reader(new JpaPagingItemReader<Schedule>())
.processor(new ScheduleExectutor())
.writer(new JpaItemWriter<Schedule>())
.build();
}
}
application.properties：
spring.jpa.hibernate.ddl-auto=none
spring.datasource.url=jdbc:postgresql://localhost:5432/my_db
spring.datasource.username=myuser
spring.datasource.password=mypassword
这是完整的日志：
$ mvn spring-boot:run
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building runner 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] >>> spring-boot-maven-plugin:1.5.3.RELEASE:run (default-cli) > test-compile @ runner >>>
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ runner ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 1 resource
[INFO] Copying 0 resource
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ runner ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ runner ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /home/msl09/unsynced/workspace/syncweb_scheduler/runner/src/test/resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ runner ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] <<< spring-boot-maven-plugin:1.5.3.RELEASE:run (default-cli) < test-compile @ runner <<<
[INFO]
[INFO] --- spring-boot-maven-plugin:1.5.3.RELEASE:run (default-cli) @ runner ---
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v1.5.3.RELEASE)
2017-06-06 12:40:55.492 INFO 21085 --- [ main] b.j.t.syncweb.runner.RunnerApplication : Starting RunnerApplication on myhost-debian with PID 21085 (/home/msl09/unsynced/workspace/syncweb_scheduler/runner/target/classes started by msl09 in /home/msl09/unsynced/workspace/syncweb_scheduler/runner)
2017-06-06 12:40:55.494 INFO 21085 --- [ main] b.j.t.syncweb.runner.RunnerApplication : No active profile set, falling back to default profiles: default
2017-06-06 12:40:55.533 INFO 21085 --- [ main] s.c.a.AnnotationConfigApplicationContext : Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@4d488830: startup date [Tue Jun 06 12:40:55 BRT 2017]; root of context hierarchy
2017-06-06 12:40:55.957 WARN 21085 --- [ main] o.s.c.a.ConfigurationClassEnhancer : @Bean method ScopeConfiguration.stepScope is non-static and returns an object assignable to Spring's BeanFactoryPostProcessor interface. This will result in a failure to process annotations such as @Autowired, @Resource and @PostConstruct within the method's declaring @Configuration class. Add the 'static' modifier to this method to avoid these container lifecycle issues; see @Bean javadoc for complete details.
2017-06-06 12:40:55.966 WARN 21085 --- [ main] o.s.c.a.ConfigurationClassEnhancer : @Bean method ScopeConfiguration.jobScope is non-static and returns an object assignable to Spring's BeanFactoryPostProcessor interface. This will result in a failure to process annotations such as @Autowired, @Resource and @PostConstruct within the method's declaring @Configuration class. Add the 'static' modifier to this method to avoid these container lifecycle issues; see @Bean javadoc for complete details.
2017-06-06 12:40:56.326 INFO 21085 --- [ main] j.LocalContainerEntityManagerFactoryBean : Building JPA container EntityManagerFactory for persistence unit 'default'
2017-06-06 12:40:56.340 INFO 21085 --- [ main] o.hibernate.jpa.internal.util.LogHelper : HHH000204: Processing PersistenceUnitInfo [
name: default
...]
2017-06-06 12:40:56.385 INFO 21085 --- [ main] org.hibernate.Version : HHH000412: Hibernate Core {5.0.12.Final}
2017-06-06 12:40:56.386 INFO 21085 --- [ main] org.hibernate.cfg.Environment : HHH000206: hibernate.properties not found
2017-06-06 12:40:56.387 INFO 21085 --- [ main] org.hibernate.cfg.Environment : HHH000021: Bytecode provider name : javassist
2017-06-06 12:40:56.431 INFO 21085 --- [ main] o.hibernate.annotations.common.Version : HCANN000001: Hibernate Commons Annotations {5.0.1.Final}
2017-06-06 12:40:56.501 INFO 21085 --- [ main] org.hibernate.dialect.Dialect : HHH000400: Using dialect: org.hibernate.dialect.PostgreSQLDialect
2017-06-06 12:40:56.621 INFO 21085 --- [ main] o.h.e.j.e.i.LobCreatorBuilderImpl : HHH000424: Disabling contextual LOB creation as createClob() method threw error : java.lang.reflect.InvocationTargetException
2017-06-06 12:40:56.622 INFO 21085 --- [ main] org.hibernate.type.BasicTypeRegistry : HHH000270: Type registration [java.util.UUID] overrides previous : org.hibernate.type.UUIDBinaryType@c3133ad
2017-06-06 12:40:56.809 INFO 21085 --- [ main] j.LocalContainerEntityManagerFactoryBean : Initialized JPA EntityManagerFactory for persistence unit 'default'
2017-06-06 12:40:57.031 WARN 21085 --- [ main] o.s.b.a.batch.BasicBatchConfigurer : JPA does not support custom isolation levels, so locks may not be taken when launching Jobs
2017-06-06 12:40:57.032 INFO 21085 --- [ main] o.s.b.c.r.s.JobRepositoryFactoryBean : No database type set, using meta data indicating: POSTGRES
2017-06-06 12:40:57.151 INFO 21085 --- [ main] o.s.b.c.l.support.SimpleJobLauncher : No TaskExecutor has been set, defaulting to synchronous executor.
2017-06-06 12:40:57.164 INFO 21085 --- [ main] o.s.jdbc.datasource.init.ScriptUtils : Executing SQL script from class path resource [org/springframework/batch/core/schema-postgresql.sql]
2017-06-06 12:40:57.964 INFO 21085 --- [ main] o.s.jdbc.datasource.init.ScriptUtils : Executed SQL script from class path resource [org/springframework/batch/core/schema-postgresql.sql] in 800 ms.
2017-06-06 12:40:58.098 INFO 21085 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2017-06-06 12:40:58.109 INFO 21085 --- [ main] o.s.b.a.b.JobLauncherCommandLineRunner : Running default command line with: []
2017-06-06 12:40:58.214 INFO 21085 --- [ main] o.s.b.c.l.support.SimpleJobLauncher : Job: [FlowJob: [name=synchronizeProcess]] launched with the following parameters: [{run.id=1}]
2017-06-06 12:40:58.238 INFO 21085 --- [ main] o.s.batch.core.job.SimpleStepHandler : Executing step: [step1]
2017-06-06 12:40:58.251 ERROR 21085 --- [ main] o.s.batch.core.step.AbstractStep : Encountered an error executing step step1 in job synchronizeProcess
org.springframework.batch.item.ItemStreamException: Failed to initialize the reader
at org.springframework.batch.item.support.AbstractItemCountingItemStreamItemReader.open(AbstractItemCountingItemStreamItemReader.java:147) ~[spring-batch-infrastructure-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.item.support.CompositeItemStream.open(CompositeItemStream.java:96) ~[spring-batch-infrastructure-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.core.step.tasklet.TaskletStep.open(TaskletStep.java:310) ~[spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.core.step.AbstractStep.execute(AbstractStep.java:197) ~[spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.core.job.SimpleStepHandler.handleStep(SimpleStepHandler.java:148) [spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.core.job.flow.JobFlowExecutor.executeStep(JobFlowExecutor.java:64) [spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.core.job.flow.support.state.StepState.handle(StepState.java:67) [spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.core.job.flow.support.SimpleFlow.resume(SimpleFlow.java:169) [spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.core.job.flow.support.SimpleFlow.start(SimpleFlow.java:144) [spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.core.job.flow.FlowJob.doExecute(FlowJob.java:134) [spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.core.job.AbstractJob.execute(AbstractJob.java:306) [spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.core.launch.support.SimpleJobLauncher$1.run(SimpleJobLauncher.java:135) [spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.core.task.SyncTaskExecutor.execute(SyncTaskExecutor.java:50) [spring-core-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.batch.core.launch.support.SimpleJobLauncher.run(SimpleJobLauncher.java:128) [spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_111]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_111]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_111]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_111]
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:333) [spring-aop-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190) [spring-aop-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) [spring-aop-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.batch.core.configuration.annotation.SimpleBatchConfiguration$PassthruAdvice.invoke(SimpleBatchConfiguration.java:127) [spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) [spring-aop-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213) [spring-aop-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at com.sun.proxy.$Proxy74.run(Unknown Source) [na:na]
at org.springframework.boot.autoconfigure.batch.JobLauncherCommandLineRunner.execute(JobLauncherCommandLineRunner.java:214) [spring-boot-autoconfigure-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.autoconfigure.batch.JobLauncherCommandLineRunner.executeLocalJobs(JobLauncherCommandLineRunner.java:231) [spring-boot-autoconfigure-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.autoconfigure.batch.JobLauncherCommandLineRunner.launchJobFromProperties(JobLauncherCommandLineRunner.java:123) [spring-boot-autoconfigure-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.autoconfigure.batch.JobLauncherCommandLineRunner.run(JobLauncherCommandLineRunner.java:117) [spring-boot-autoconfigure-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:776) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:760) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.SpringApplication.afterRefresh(SpringApplication.java:747) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1162) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1151) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at br.jus.tjse.syncweb.runner.RunnerApplication.main(RunnerApplication.java:10) [classes/:na]
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.boot.maven.AbstractRunMojo$LaunchRunner.run(AbstractRunMojo.java:527) [spring-boot-maven-plugin-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at java.lang.Thread.run(Thread.java:745) [na:1.8.0_111]
Caused by: java.lang.NullPointerException: null
at org.springframework.batch.item.database.JpaPagingItemReader.doOpen(JpaPagingItemReader.java:177) ~[spring-batch-infrastructure-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.item.support.AbstractItemCountingItemStreamItemReader.open(AbstractItemCountingItemStreamItemReader.java:144) ~[spring-batch-infrastructure-3.0.7.RELEASE.jar:3.0.7.RELEASE]
... 41 common frames omitted
2017-06-06 12:40:58.264 ERROR 21085 --- [ main] o.s.batch.core.step.AbstractStep : Exception while closing step execution resources in step step1 in job synchronizeProcess
org.springframework.batch.item.ItemStreamException: Error while closing item reader
at org.springframework.batch.item.support.AbstractItemCountingItemStreamItemReader.close(AbstractItemCountingItemStreamItemReader.java:136) ~[spring-batch-infrastructure-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.item.support.CompositeItemStream.close(CompositeItemStream.java:85) ~[spring-batch-infrastructure-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.core.step.tasklet.TaskletStep.close(TaskletStep.java:305) ~[spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.core.step.AbstractStep.execute(AbstractStep.java:271) ~[spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.core.job.SimpleStepHandler.handleStep(SimpleStepHandler.java:148) [spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.core.job.flow.JobFlowExecutor.executeStep(JobFlowExecutor.java:64) [spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.core.job.flow.support.state.StepState.handle(StepState.java:67) [spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.core.job.flow.support.SimpleFlow.resume(SimpleFlow.java:169) [spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.core.job.flow.support.SimpleFlow.start(SimpleFlow.java:144) [spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.core.job.flow.FlowJob.doExecute(FlowJob.java:134) [spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.core.job.AbstractJob.execute(AbstractJob.java:306) [spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.core.launch.support.SimpleJobLauncher$1.run(SimpleJobLauncher.java:135) [spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.core.task.SyncTaskExecutor.execute(SyncTaskExecutor.java:50) [spring-core-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.batch.core.launch.support.SimpleJobLauncher.run(SimpleJobLauncher.java:128) [spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_111]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_111]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_111]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_111]
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:333) [spring-aop-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190) [spring-aop-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) [spring-aop-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.batch.core.configuration.annotation.SimpleBatchConfiguration$PassthruAdvice.invoke(SimpleBatchConfiguration.java:127) [spring-batch-core-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) [spring-aop-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213) [spring-aop-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at com.sun.proxy.$Proxy74.run(Unknown Source) [na:na]
at org.springframework.boot.autoconfigure.batch.JobLauncherCommandLineRunner.execute(JobLauncherCommandLineRunner.java:214) [spring-boot-autoconfigure-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.autoconfigure.batch.JobLauncherCommandLineRunner.executeLocalJobs(JobLauncherCommandLineRunner.java:231) [spring-boot-autoconfigure-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.autoconfigure.batch.JobLauncherCommandLineRunner.launchJobFromProperties(JobLauncherCommandLineRunner.java:123) [spring-boot-autoconfigure-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.autoconfigure.batch.JobLauncherCommandLineRunner.run(JobLauncherCommandLineRunner.java:117) [spring-boot-autoconfigure-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:776) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:760) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.SpringApplication.afterRefresh(SpringApplication.java:747) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1162) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1151) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at br.jus.tjse.syncweb.runner.RunnerApplication.main(RunnerApplication.java:10) [classes/:na]
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.boot.maven.AbstractRunMojo$LaunchRunner.run(AbstractRunMojo.java:527) [spring-boot-maven-plugin-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at java.lang.Thread.run(Thread.java:745) [na:1.8.0_111]
Caused by: java.lang.NullPointerException: null
at org.springframework.batch.item.database.JpaPagingItemReader.doClose(JpaPagingItemReader.java:236) ~[spring-batch-infrastructure-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.batch.item.support.AbstractItemCountingItemStreamItemReader.close(AbstractItemCountingItemStreamItemReader.java:133) ~[spring-batch-infrastructure-3.0.7.RELEASE.jar:3.0.7.RELEASE]
... 41 common frames omitted
2017-06-06 12:40:58.305 INFO 21085 --- [ main] o.s.b.c.l.support.SimpleJobLauncher : Job: [FlowJob: [name=synchronizeProcess]] completed with the following parameters: [{run.id=1}] and the following status: [FAILED]
2017-06-06 12:40:58.307 INFO 21085 --- [ main] b.j.t.syncweb.runner.RunnerApplication : Started RunnerApplication in 3.142 seconds (JVM running for 5.223)
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 4.444 s
[INFO] Finished at: 2017-06-06T12:40:58-03:00
[INFO] Final Memory: 34M/351M
[INFO] ------------------------------------------------------------------------
2017-06-06 12:40:58.478 INFO 21085 --- [ Thread-3] s.c.a.AnnotationConfigApplicationContext : Closing org.springframework.context.annotation.AnnotationConfigApplicationContext@4d488830: startup date [Tue Jun 06 12:40:55 BRT 2017]; root of context hierarchy
2017-06-06 12:40:58.479 INFO 21085 --- [ Thread-3] o.s.j.e.a.AnnotationMBeanExporter : Unregistering JMX-exposed beans on shutdown
2017-06-06 12:40:58.480 INFO 21085 --- [ Thread-3] j.LocalContainerEntityManagerFactoryBean : Closing JPA EntityManagerFactory for persistence unit 'default'
实例化 JpaPaginItemReader 的正确方法是什么？
【问题讨论】：
-
这里没有足够的信息——也许是堆栈跟踪，你在教程的哪里？
-
您需要将其定义为
@Bean并注入EntityManagerFactory，您显然需要告诉它执行哪个查询来获取您的项目。这同样适用于作家。