我是spring的新手，可以将数据库拆分为3个csv文件。
我的实际代码：（我不使用xml，也不想）
我尝试了很多解决方案，但没有任何效果。
class MyClassifier {
@Classifier
public String classify(Pojo Pojo) {
return String.valueOf(Pojo.getYear());
}
}
@Bean(name = "PojoWriter")
@StepScope
public ItemWriter<Pojo> itemWriter() throws Exception {
BackToBackPatternClassifier classifier = new BackToBackPatternClassifier();
classifier.setRouterDelegate(new MyClassifier());
classifier.setMatcherMap(new HashMap<String, FlatFileItemWriter<? super Pojo>>() {
FlatFileItemWriter<Pojo> writerH;
{
writerH = writer("2017",null,null); put("2017", writerH); writerH.close();
writerH = writer("2018",null,null); put("2018", writerH); writerH.close();
writerH = writer("2019",null,null); put("2019", writerH); writerH.close();
}
});
ClassifierCompositeItemWriter<Pojo> writer = new ClassifierCompositeItemWriter<Pojo>();
writer.setClassifier(classifier);
return writer;
}
我用年份分类，并且创建了3个文件
// @Bean(name = "FlatWriter")
// @StepScope
public FlatFileItemWriter<Pojo> writer( final String name,
@Value("#{stepExecutionContext['fromId']}") final String fromId,
@Value("#{stepExecutionContext['toId']}") final String toId) throws Exception {
FlatFileItemWriter<Pojo> writer = new FlatFileItemWriter<Pojo>();
writer.setResource(new FileSystemResource(name + ".csv"));
writer.setShouldDeleteIfExists(true);
writer.open(new ExecutionContext());
writer.setHeaderCallback(new FlatFileHeaderCallback() {
@Override
public void writeHeader(Writer writer) throws IOException {
writer.write(
"Id, number, name");
}
});
writer.setLineAggregator(new DelimitedLineAggregator<Pojo>() {
{
setDelimiter(",");
setFieldExtractor(new BeanWrapperFieldExtractor<Pojo>() {
{
setNames(new String[] { "Id", "number", "name" });
}
});
}
});
return writer;
}
@Bean
@StepScope
public Step step1() throws Exception {
return stepBuilderFactory.get("step1").<Foo, Pojo>chunk(10)
.reader(reader())
.processor(processor())
.writer(itemWriter())
.build();
}
@Bean
public Job exportUserJob() throws Exception {
return jobBuilderFactory.get("exportUserJob")
.flow(step1()).end().build();
}
参数：
@Component
@EnableBatchProcessing
@Configurable
和spring.batch.job.enabled=false
错误的堆栈跟踪：
2019-07-15 11：13：44.666错误12632-[[Spring Shell] o.s.batch.core.step.AbstractStep：在作业exportUserJob中执行步骤step1时遇到错误
org.springframework.batch.item.WriterNotOpenException：必须先打开Writer，然后才能将其写入 在org.springframework.batch.item.file.FlatFileItemWriter.write（FlatFileItemWriter.java:255）〜[spring-batch-infrastructure-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.batch.item.support.ClassifierCompositeItemWriter.write（ClassifierCompositeItemWriter.java:66）〜[spring-batch-infrastructure-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.batch.core.step.item.SimpleChunkProcessor.writeItems（SimpleChunkProcessor.java:175）〜[spring-batch-core-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.batch.core.step.item.SimpleChunkProcessor.doWrite（SimpleChunkProcessor.java:151）〜[spring-batch-core-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.batch.core.step.item.SimpleChunkProcessor.write（SimpleChunkProcessor.java:274）〜[spring-batch-core-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.batch.core.step.item.SimpleChunkProcessor.process（SimpleChunkProcessor.java:199）〜[spring-batch-core-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.batch.core.step.item.ChunkOrientedTasklet.execute（ChunkOrientedTasklet.java:75）〜[spring-batch-core-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.batch.core.step.tasklet.TaskletStep $ ChunkTransactionCallback.doInTransaction（TaskletStep.java:406）〜[spring-batch-core-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.batch.core.step.tasklet.TaskletStep $ ChunkTransactionCallback.doInTransaction（TaskletStep.java:330）〜[spring-batch-core-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.transaction.support.TransactionTemplate.execute（TransactionTemplate.java:133）〜[spring-tx-4.2.6.RELEASE.jar：4.2.6.RELEASE] 在org.springframework.batch.core.step.tasklet.TaskletStep $ 2.doInChunkContext（TaskletStep.java:271）〜[spring-batch-core-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.batch.core.scope.context.StepContextRepeatCallback.doInIteration（StepContextRepeatCallback.java:81）〜[spring-batch-core-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.batch.repeat.support.RepeatTemplate.getNextResult（RepeatTemplate.java:374）〜[spring-batch-infrastructure-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.batch.repeat.support.RepeatTemplate.executeInternal（RepeatTemplate.java:215）〜[spring-batch-infrastructure-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.batch.repeat.support.RepeatTemplate.iterate（RepeatTemplate.java:144）〜[spring-batch-infrastructure-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.batch.core.step.tasklet.TaskletStep.doExecute（TaskletStep.java:257）〜[spring-batch-core-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.batch.core.step.AbstractStep.execute（AbstractStep.java:200）〜[spring-batch-core-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.batch.core.job.SimpleStepHandler.handleStep（SimpleStepHandler.java:148）上[spring-batch-core-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.batch.core.job.flow.JobFlowExecutor.executeStep（JobFlowExecutor.java:64）上[spring-batch-core-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在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] 在org.springframework.batch.core.job.flow.support.SimpleFlow.resume（SimpleFlow.java:169）[spring-batch-core-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.batch.core.job.flow.support.SimpleFlow.start（SimpleFlow.java:144）[spring-batch-core-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.batch.core.job.flow.FlowJob.doExecute（FlowJob.java:134）[spring-batch-core-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.batch.core.job.AbstractJob.execute（AbstractJob.java:306）[spring-batch-core-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.batch.core.launch.support.SimpleJobLauncher $ 1.run（SimpleJobLauncher.java:135）[spring-batch-core-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.core.task.SyncTaskExecutor.execute（SyncTaskExecutor.java:50）上[spring-core-4.2.6.RELEASE.jar：4.2.6.RELEASE] 在org.springframework.batch.core.launch.support.SimpleJobLauncher.run（SimpleJobLauncher.java:128）[spring-batch-core-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在sun.reflect.NativeMethodAccessorImpl.invoke0（本机方法）〜[na：1.8.0_161] 在sun.reflect.NativeMethodAccessorImpl.invoke（未知来源）〜[na：1.8.0_161] 在sun.reflect.DelegatingMethodAccessorImpl.invoke（未知来源）〜[na：1.8.0_161] 在java.lang.reflect.Method.invoke（未知来源）〜[na：1.8.0_161] 在org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection（AopUtils.java:302）[spring-aop-4.2.6.RELEASE.jar：4.2.6.RELEASE] 在org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint（ReflectiveMethodInvocation.java:190）[spring-aop-4.2.6.RELEASE.jar：4.2.6.RELEASE] 在org.springframework.aop.framework.ReflectiveMethodInvocation.proceed（ReflectiveMethodInvocation.java:157）[spring-aop-4.2.6.RELEASE.jar：4.2.6.RELEASE] 在org.springframework.batch.core.configuration.annotation.SimpleBatchConfiguration $ PassthruAdvice.invoke（SimpleBatchConfiguration.java:127）[spring-batch-core-3.0.7.RELEASE.jar：3.0.7.RELEASE] 在org.springframework.aop.framework.ReflectiveMethodInvocation.proceed（ReflectiveMethodInvocation.java:179）上[spring-aop-4.2.6.RELEASE.jar：4.2.6.RELEASE] 在org.springframework.aop.framework.JdkDynamicAopProxy.invoke（JdkDynamicAopProxy.java:208）[spring-aop-4.2.6.RELEASE.jar：4.2.6.RELEASE] 在com.sun.proxy。$ Proxy80.run（未知来源）[na：na] 在com.viviane.commands.CsvGenerator.transactionalCsvBuilder（CsvGenerator.java:700）[classes /：na] 在com.viviane.commands.Scanner.createFiles（Scanner.java:93）[classes /：na] 在sun.reflect.NativeMethodAccessorImpl.invoke0（本机方法）〜[na：1.8.0_161] 在sun.reflect.NativeMethodAccessorImpl.invoke（未知来源）〜[na：1.8.0_161] 在sun.reflect.DelegatingMethodAccessorImpl.invoke（未知来源）〜[na：1.8.0_161] 在java.lang.reflect.Method.invoke（未知来源）〜[na：1.8.0_161] 在org.springframework.util.ReflectionUtils.invokeMethod（ReflectionUtils.java:216）[spring-core-4.2.6.RELEASE.jar：4.2.6.RELEASE] 在org.springframework.shell.core.SimpleExecutionStrategy.invoke（SimpleExecutionStrategy.java:64）上[spring-shell-1.1.0.RELEASE.jar：1.1.0.RELEASE] 在org.springframework.shell.core.SimpleExecutionStrategy.execute（SimpleExecutionStrategy.java:57）[spring-shell-1.1.0.RELEASE.jar：1.1.0.RELEASE] 在org.springframework.shell.core.AbstractShell.executeCommand（AbstractShell.java:127）上[spring-shell-1.1.0.RELEASE.jar：1.1.0.RELEASE] 在org.springframework.shell.core.JLineShell.promptLoop（JLineShell.java:533）[spring-shell-1.1.0.RELEASE.jar：1.1.0.RELEASE] 在org.springframework.shell.core.JLineShell.run（JLineShell.java:179）[spring-shell-1.1.0.RELEASE.jar：1.1.0.RELEASE] 在java.lang.Thread.run（未知来源）[na：1.8.0_161]