Question

尝试从Spring Batch应用程序中的数据库读取时遇到以下异常。任何见解都会有所帮助。这是在使用JdbcCursorItemReader时引起的。使用JdbcPagingItemReader可以正常运行该应用程序。

使用JdbcCursorItemReader时还需要显式关闭任何资源（游标等）吗？如果是这样，我们该怎么做？

SEVERE: Encountered an error executing the step
    org.springframework.dao.InvalidDataAccessResourceUsageException: Unexpected cursor position change.
        at org.springframework.batch.item.database.AbstractCursorItemReader.verifyCursorPosition(AbstractCursorItemReader.java:365)
        at org.springframework.batch.item.database.AbstractCursorItemReader.doRead(AbstractCursorItemReader.java:449)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:601)
        at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
        at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:695)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
        at org.springframework.aop.support.DelegatingIntroductionInterceptor.doProceed(DelegatingIntroductionInterceptor.java:132)
        at org.springframework.aop.support.DelegatingIntroductionInterceptor.invoke(DelegatingIntroductionInterceptor.java:120)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
        at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:631)
        at com.testapp.springbatchtest.io.DataExtractCursorItemReader$$EnhancerByCGLIB$$748012e7.doRead(<generated>)
        at org.springframework.batch.item.support.AbstractItemCountingItemStreamItemReader.read(AbstractItemCountingItemStreamItemReader.java:83)
        at org.springframework.batch.core.step.item.SimpleChunkProvider.doRead(SimpleChunkProvider.java:91)
        at org.springframework.batch.core.step.item.SimpleChunkProvider.read(SimpleChunkProvider.java:155)
        at org.springframework.batch.core.step.item.SimpleChunkProvider$1.doInIteration(SimpleChunkProvider.java:114)
        at org.springframework.batch.repeat.support.RepeatTemplate.getNextResult(RepeatTemplate.java:368)
        at org.springframework.batch.repeat.support.RepeatTemplate.executeInternal(RepeatTemplate.java:215)
        at org.springframework.batch.repeat.support.RepeatTemplate.iterate(RepeatTemplate.java:144)
        at org.springframework.batch.core.step.item.SimpleChunkProvider.provide(SimpleChunkProvider.java:108)
        at org.springframework.batch.core.step.item.ChunkOrientedTasklet.execute(ChunkOrientedTasklet.java:69)
        at org.springframework.batch.core.step.tasklet.TaskletStep$ChunkTransactionCallback.doInTransaction(TaskletStep.java:395)
        at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:131)
        at org.springframework.batch.core.step.tasklet.TaskletStep$2.doInChunkContext(TaskletStep.java:267)
        at org.springframework.batch.core.scope.context.StepContextRepeatCallback.doInIteration(StepContextRepeatCallback.java:77)
        at org.springframework.batch.repeat.support.RepeatTemplate.getNextResult(RepeatTemplate.java:368)
        at org.springframework.batch.repeat.support.RepeatTemplate.executeInternal(RepeatTemplate.java:215)
        at org.springframework.batch.repeat.support.RepeatTemplate.iterate(RepeatTemplate.java:144)
        at org.springframework.batch.core.step.tasklet.TaskletStep.doExecute(TaskletStep.java:253)
        at org.springframework.batch.core.step.AbstractStep.execute(AbstractStep.java:195)
        at org.springframework.batch.core.job.SimpleStepHandler.handleStep(SimpleStepHandler.java:137)
        at org.springframework.batch.core.job.AbstractJob.handleStep(AbstractJob.java:380)
        at org.springframework.batch.core.job.SimpleJob.doExecute(SimpleJob.java:124)
        at org.springframework.batch.core.job.AbstractJob.execute(AbstractJob.java:301)
        at org.springframework.batch.core.launch.support.SimpleJobLauncher$1.run(SimpleJobLauncher.java:134)
        at org.springframework.core.task.SyncTaskExecutor.execute(SyncTaskExecutor.java:49)
        at org.springframework.batch.core.launch.support.SimpleJobLauncher.run(SimpleJobLauncher.java:127)

以下是bean声明的示例代码。 DataExtractCursorItemReader扩展了JdbcCursorItemReader。

@Bean
@StepScope
public DataExtractCursorItemReader cursorReaderBean() throws Exception {
    DataExtractCursorItemReader dataExtractReader = new DataExtractCursorItemReader();
    dataExtractReader.setDataSource(dataSource);
    dataExtractReader.setSql("SELECT * FROM SAMPLETABLE");
    dataExtractReader.setFetchSize(500);
    dataExtractReader.setRowMapper(new DataExtractRowMapper());

    return dataExtractReader;
}

Answer 1

verifyCursorPosition属性（似乎）只是检查以防止用户在继承读取器时进行索引操作;也许是你的情况，或者某些数据库平台属性可能不起作用。

你可以禁用它，一切都应该正常工作 - 这只是一个防止子类化的测试如果您修改光标位置或检查测试是否因数据库驱动程序而失败，请检查您的代码。

Answer 2

如果有多个线程作用于数据库读取器且读取器不是线程安全的，则会看到此错误通常是JDBCCursorItemReader与JDBCPagingItemReader

Answer 3

verifyCursorPosition 检查取决于java.sql.ResultSet :: getRow（）。＆＃34;对结果集类型为TYPE_FORWARD_ONLY＆＃34;的ResultSets，getRow方法的支持是可选的。根据{{3}}

您可以尝试更改驱动程序，ResultSet类型（Reader），或按照上述建议禁用 verifyCursorPosition

InvalidDataAccessResourceUsageException：意外的光标位置更改

3 个答案: