为什么我会得到异常"Found ambiguous parameter type"？春季批量集成

Question

我从这里学习Spring Batch Integration，我知道如何在收到消息时启动作业。现在，我想得到消息的名称和路径(这是一个文件(。以下是我的工作代码。但是，如果我取消注释setFileParameterName方法，那么我会得到以下异常：

java.lang.IllegalArgumentException: Found ambiguous parameter type [class java.lang.String] for method match: [public void com.example.batchprocessing.FileMessageToJobRequest.setFileParameterName(java.lang.String), public void com.example.batchprocessing.FileMessageToJobRequest.setJob(org.springframework.batch.core.Job)]

为什么会出现这种异常？这条消息对我来说毫无意义。我传入了一个String，但不知何故，它在两个方法之间混淆了，但其中一个方法传入了String，另一个方法则传入了Job？如有任何帮助，我们将不胜感激。

FileMessageToJobRequest.java

public class FileMessageToJobRequest {
private String filePathParameterName;
private Job job;
private String fileParameterName;
public void setFilePathParameterName(String filePathParameterName) {
this.filePathParameterName = filePathParameterName;
}
public void setJob(Job job) {
this.job = job;
}
//  public void setFileParameterName(String fileParameterName) {
//      this.fileParameterName = fileParameterName;
//  }
@Transformer
public JobLaunchRequest toRequest(Message<File> message) throws IOException {
JobParametersBuilder jobParametersBuilder = new JobParametersBuilder();
//      jobParametersBuilder.addString(fileParameterName, message.getPayload().getName());
jobParametersBuilder.addString(filePathParameterName, message.getPayload().getCanonicalPath());
jobParametersBuilder.addDate("dummy", new Date()); // need to add at least one unique identifier so that it will run more than once
return new JobLaunchRequest(job, jobParametersBuilder.toJobParameters());
}
}

BatchIntegrationConfiguration.java

@Configuration
@EnableIntegration
@EnableBatchProcessing
public class BatchIntegrationConfiguration {
@Autowired
private JobBuilderFactory jobBuilderFactory;
@Autowired
private StepBuilderFactory stepBuilderFactory;
@Autowired
private JobRepository jobRepository;
@Bean
public MessageChannel files() {
return new DirectChannel();
}
@Bean
public FileMessageToJobRequest fileMessageToJobRequest() {
FileMessageToJobRequest fileMessageToJobRequest = new FileMessageToJobRequest();
//      fileMessageToJobRequest.setFileParameterName("input.file.name")
fileMessageToJobRequest.setFilePathParameterName("input.file.path");
fileMessageToJobRequest.setJob(runBatchScriptJob());
return fileMessageToJobRequest;
}
@Bean
public JobLaunchingGateway jobLaunchingGateway() {
SimpleJobLauncher simpleJobLauncher = new SimpleJobLauncher();
simpleJobLauncher.setJobRepository(jobRepository);
simpleJobLauncher.setTaskExecutor(new SyncTaskExecutor());
JobLaunchingGateway jobLaunchingGateway = new JobLaunchingGateway(simpleJobLauncher);
return jobLaunchingGateway;
}
@Bean
public IntegrationFlow integrationFlow(JobLaunchingGateway jobLaunchingGateway) {
return IntegrationFlows.from(Files.inboundAdapter(new File("./src/main/resources")).
filter(new SimplePatternFileListFilter("simplebatchfile.bat")),
c -> c.poller(Pollers.fixedRate(10000).maxMessagesPerPoll(1))).
handle(fileMessageToJobRequest()).
handle(jobLaunchingGateway).
log(LoggingHandler.Level.WARN, "headers.id + ': ' + payload").
get();
}
@Bean
public Job runBatchScriptJob() {
return jobBuilderFactory.get("runBatchScriptJob")
.listener(new JobCompletionNotificationListener())
.start(runBatchScriptStep())
.build();
}
@Bean
public Step runBatchScriptStep() {
return stepBuilderFactory.get("runBatchScriptStep")
.tasklet(runBatchScriptTasklet(null))
.build();
}
@Bean
@StepScope
public Tasklet runBatchScriptTasklet(@Value("#{jobParameters['input.file.path']}") String filePath) {
RunBatchScriptTasklet tasklet = new RunBatchScriptTasklet();
tasklet.setFilePath(filePath);
return tasklet;
}
}

StackTrace

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'integrationFlow' defined in class path resource [com/example/batchprocessing/BatchIntegrationConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.integration.dsl.IntegrationFlow]: Factory method 'integrationFlow' threw exception; nested exception is java.lang.IllegalArgumentException: Found ambiguous parameter type [class java.lang.String] for method match: [public void com.example.batchprocessing.FileMessageToJobRequest.setFileParameterName(java.lang.String), public void com.example.batchprocessing.FileMessageToJobRequest.setJob(org.springframework.batch.core.Job)]
at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:656) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:636) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1338) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:879) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:878) ~[spring-context-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) ~[spring-context-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747) [spring-boot-2.2.5.RELEASE.jar:2.2.5.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) [spring-boot-2.2.5.RELEASE.jar:2.2.5.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-2.2.5.RELEASE.jar:2.2.5.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) [spring-boot-2.2.5.RELEASE.jar:2.2.5.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215) [spring-boot-2.2.5.RELEASE.jar:2.2.5.RELEASE]
at com.example.batchprocessing.BatchProcessingApplication.main(BatchProcessingApplication.java:14) [classes/:na]
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.integration.dsl.IntegrationFlow]: Factory method 'integrationFlow' threw exception; nested exception is java.lang.IllegalArgumentException: Found ambiguous parameter type [class java.lang.String] for method match: [public void com.example.batchprocessing.FileMessageToJobRequest.setFileParameterName(java.lang.String), public void com.example.batchprocessing.FileMessageToJobRequest.setJob(org.springframework.batch.core.Job)]
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:651) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
... 18 common frames omitted
Caused by: java.lang.IllegalArgumentException: Found ambiguous parameter type [class java.lang.String] for method match: [public void com.example.batchprocessing.FileMessageToJobRequest.setFileParameterName(java.lang.String), public void com.example.batchprocessing.FileMessageToJobRequest.setJob(org.springframework.batch.core.Job)]
at org.springframework.util.Assert.isNull(Assert.java:176) ~[spring-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.integration.handler.support.MessagingMethodInvokerHelper.validateFallbackMethods(MessagingMethodInvokerHelper.java:755) ~[spring-integration-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.integration.handler.support.MessagingMethodInvokerHelper.findHandlerMethodsForTarget(MessagingMethodInvokerHelper.java:740) ~[spring-integration-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.integration.handler.support.MessagingMethodInvokerHelper.<init>(MessagingMethodInvokerHelper.java:294) ~[spring-integration-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.integration.handler.support.MessagingMethodInvokerHelper.<init>(MessagingMethodInvokerHelper.java:231) ~[spring-integration-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.integration.handler.support.MessagingMethodInvokerHelper.<init>(MessagingMethodInvokerHelper.java:225) ~[spring-integration-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.integration.handler.MethodInvokingMessageProcessor.<init>(MethodInvokingMessageProcessor.java:62) ~[spring-integration-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.integration.handler.ServiceActivatingHandler.<init>(ServiceActivatingHandler.java:39) ~[spring-integration-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.integration.dsl.BaseIntegrationFlowDefinition.handle(BaseIntegrationFlowDefinition.java:960) ~[spring-integration-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.integration.dsl.IntegrationFlowDefinition.handle(IntegrationFlowDefinition.java:510) ~[spring-integration-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.integration.dsl.IntegrationFlowDefinition.handle(IntegrationFlowDefinition.java:65) ~[spring-integration-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.integration.dsl.BaseIntegrationFlowDefinition.handle(BaseIntegrationFlowDefinition.java:939) ~[spring-integration-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.integration.dsl.IntegrationFlowDefinition.handle(IntegrationFlowDefinition.java:503) ~[spring-integration-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.integration.dsl.IntegrationFlowDefinition.handle(IntegrationFlowDefinition.java:65) ~[spring-integration-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.integration.dsl.BaseIntegrationFlowDefinition.handle(BaseIntegrationFlowDefinition.java:926) ~[spring-integration-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.integration.dsl.IntegrationFlowDefinition.handle(IntegrationFlowDefinition.java:498) ~[spring-integration-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at com.example.batchprocessing.BatchIntegrationConfiguration.integrationFlow(BatchIntegrationConfiguration.java:78) ~[classes/:na]
at com.example.batchprocessing.BatchIntegrationConfiguration$$EnhancerBySpringCGLIB$$238a9f8a.CGLIB$integrationFlow$1(<generated>) ~[classes/:na]
at com.example.batchprocessing.BatchIntegrationConfiguration$$EnhancerBySpringCGLIB$$238a9f8a$$FastClassBySpringCGLIB$$b8a5aaf.invoke(<generated>) ~[classes/:na]
at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244) ~[spring-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:331) ~[spring-context-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at com.example.batchprocessing.BatchIntegrationConfiguration$$EnhancerBySpringCGLIB$$238a9f8a.integrationFlow(<generated>) ~[classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_211]
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_211]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_211]
at java.lang.reflect.Method.invoke(Unknown Source) ~[na:1.8.0_211]
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
... 19 common frames omitted

Answer 1

这个handle(fileMessageToJobRequest())必须更改为transform(fileMessageToJobRequest())，因为您的FileMessageToJobRequest实际上是@Transformer。handle()不理解该注释，并试图找出在运行时执行的任何候选方法。

消息Found ambiguous parameter type意味着有几种具有不同参数的方法可以作为消息处理候选者。在这种情况下，我们需要更加具体。就像你的@Transformer是一个很好的标记，但它用错了地方——handle()代表@ServiceActivator。