Spring集成文件读取 [英] Spring Integration File reading

问题描述

我是 Spring Integration 的新手.我正在研究解决方案，但在使用入站文件适配器 ( FileReadingMessageSource ) 时遇到了特定问题.我必须从不同目录读取文件并处理它们并将文件保存在不同目录中.据我了解，目录名称在流程开始时是固定的.有人可以帮助我更改不同请求的目录名称吗.

I am newbie to Spring Integration. I am working on solution, but I am stuck on a specific issue while using inbound file adapter ( FileReadingMessageSource ). I have to read files from different directories and process them and save the files in different directories. As I understand, the directory name is fixed at the start of the flow. Can some one help me on changing the directory name for different requests.

我尝试了以下操作.首先，我不确定这是否是正确的方法，尽管它只适用于一个目录.我认为 Poller 正在等待更多文件并且再也没有回来读取另一个目录.

I attempted the following. First of all, I am not sure whether it is correct way to about and although it worked for only one directory. I think Poller was waiting for more files and never came back to read another directory.

@SpringBootApplication
@EnableIntegration
@IntegrationComponentScan
public class SiSampleFileProcessor {

    @Autowired
    MyFileProcessor myFileProcessor;

    @Value("${si.outdir}")
    String outDir;

    @Autowired
    Environment env;

    public static void main(String[] args) throws IOException {
        ConfigurableApplicationContext ctx = new SpringApplication(SiSampleFileProcessor.class).run(args);
        FileProcessingService gateway = ctx.getBean(FileProcessingService.class);
        boolean process = true;
        while (process) {
            System.out.println("Please enter the input Directory: ");
            String inDir = new Scanner(System.in).nextLine();
            if ( inDir.isEmpty() || inDir.equals("exit") ) {
                process=false;
            } else {
                System.out.println("Processing... " + inDir);
                gateway.processFilesin(inDir);
            }
        }
        ctx.close();
    }

    @MessagingGateway(defaultRequestChannel="requestChannel")
    public interface FileProcessingService {
        String processFilesin( String inputDir );
    }

    @Bean(name = PollerMetadata.DEFAULT_POLLER)
    public PollerMetadata poller() {                                      
    return Pollers.fixedDelay(1000).get();
    }

    @Bean
    public MessageChannel requestChannel() {
        return new DirectChannel();
    }

    @ServiceActivator(inputChannel = "requestChannel")
    @Bean 
    GenericHandler<String> fileReader() {
        return new GenericHandler<String>() {
            @Override
            public Object handle(String p, Map<String, Object> map) {
                FileReadingMessageSource fileSource = new FileReadingMessageSource();
                fileSource.setDirectory(new File(p));
                Message<File> msg;
                while( (msg = fileSource.receive()) != null ) {
                    fileInChannel().send(msg);
                }
                return null;  // Not sure what to return!
            }
        };
    }

    @Bean
    public MessageChannel fileInChannel() {
        return MessageChannels.queue("fileIn").get();
    }

    @Bean
    public IntegrationFlow fileProcessingFlow() {
        return IntegrationFlows.from(fileInChannel())
                .handle(myFileProcessor)
                .handle(Files.outboundAdapter(new File(outDir)).autoCreateDirectory(true).get())
                .get();
    }    
}

根据 Gary 的回复，将一些方法替换为

Based on Gary's response replaced some methods as

@MessagingGateway(defaultRequestChannel="requestChannel")
public interface FileProcessingService {
    boolean processFilesin( String inputDir );
}

@ServiceActivator(inputChannel = "requestChannel")
public boolean fileReader(String inDir) {
    FileReadingMessageSource fileSource = new FileReadingMessageSource();
    fileSource.setDirectory(new File(inDir));
    fileSource.afterPropertiesSet();
    fileSource.start();
    Message<File> msg;
    while ((msg = fileSource.receive()) != null) {
        fileInChannel().send(msg);
    }
    fileSource.stop();
    System.out.println("Sent all files in directory: " + inDir);
    return true;
}

现在它按预期工作.

推荐答案

FileReadingMessageSource 在内部使用了一个 DirectoryScanner；它通常在注入属性后由 Spring 设置.由于您在 Spring 之外管理对象，因此需要调用 Spring bean 初始化和生命周期方法 afterPropertiesSet() 、 start() 和 stop().

The FileReadingMessageSource uses a DirectoryScanner internally; it is normally set up by Spring after the properties are injected. Since you are managing the object outside of Spring, you need to call Spring bean initialization and lifecycle methods afterPropertiesSet() , start() and stop().

当接收返回 null 时调用 stop().

Call stop() when the receive returns null.

> return null;  // Not sure what to return!

如果你什么都不返回，你的调用线程将挂在网关中等待响应.您可以更改网关以返回 void 或者，由于您的网关需要一个字符串，因此只需返回一些值.

If you return nothing, your calling thread will hang in the gateway waiting for a response. You could change the gateway to return void or, since your gateway is expecting a String, just return some value.

但是，您的调用代码无论如何都不会查看结果.

However, your calling code is not looking at the result anyway.

> gateway.processFilesin(inDir);

另外，从@ServiceActivator中删除@Bean；使用这种风格，bean 类型必须是 MessageHandler.

Also, remove the @Bean from the @ServiceActivator; with that style, the bean type must be MessageHandler.

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