Spring SFTP入站适配器出现问题

Question

I have a requirement for collecting files from an SFTP location and putting it into a local input directory at a regular interval. After the file is transferred, the file gets deleted from the SFTP location. For the trigger I am using a customized Cron Trigger in which I am dynamically changing the interval. Below are the entries in context.xml and the code for the CustomCronTrigger class.

<bean id="sftpSessionFactory" class="org.springframework.integration.sftp.session.DefaultSftpSessionFactory">
    <property name="host" value="127.0.0.1"/>
    <property name="port" value="22"/>
    <property name="user" value="user"/>
    <property name="password" value="passwd"/>
</bean>

<int-sftp:inbound-channel-adapter id="sftpInboundAdapter"
        channel="receiveChannel" 
        session-factory="sftpSessionFactory" 
        local-directory="/home/sftpUser"
        remote-directory="/home/input"
        delete-remote-files="true"
        auto-create-local-directory="true"
        filename-pattern="*.csv"
        >
    <int:poller trigger="customCronTrigger"/>

</int-sftp:inbound-channel-adapter>

<int:channel id="receiveChannel">
    <int:queue/>
</int:channel>

public class CustomCronTrigger implements Trigger{

    private CronSequenceGenerator sequenceGenerator;

    private String intervalInMin;

    public void setIntervalInMin(String intervalInMin) throws Exception
    {
        this.intervalInMin = intervalInMin;
        createCronExpression();
    }

    /** The logger instance */
    private Logger logger = LoggerFactory.getLogger(getClass());

    public CronSequenceGenerator getSequenceGenerator() {
        return sequenceGenerator;
    }

    public void createCronExpression() throws Exception {
        String cronExpression = getCronExpression(intervalInMin);
        logger.debug("CustomCronTrigger.setSequenceGeneratorStr()::cronExpression="+cronExpression);
        this.sequenceGenerator = new CronSequenceGenerator(cronExpression, TimeZone.getDefault());
    }

    public Date nextExecutionTime(TriggerContext triggerContext) {
        Date date = triggerContext.lastCompletionTime();
        if (date != null) {
            Date scheduled = triggerContext.lastScheduledExecutionTime();
            if (scheduled != null && date.before(scheduled)) {
                // Previous task apparently executed too early...
                // Let's simply use the last calculated execution time then,
                // in order to prevent accidental re-fires in the same second.
                date = scheduled;
            }
        }
        else {
            date = new Date();
        }
        return this.sequenceGenerator.next(date);
    }

    public String getCronExpression(String min) throws Exception
    {
        if(Integer.parseInt(min)<0 || Integer.parseInt(min)>59 )
        {
            throw new Exception(String.format("Minute %s not valid. Please enter minute between 0-59",min));
        }
        String cronExpression = "0 0/"+min+" * * * ?";
        return cronExpression;
    }


    @Override
    public boolean equals(Object obj) {
        return (this == obj || (obj instanceof CustomCronTrigger &&
                this.sequenceGenerator.equals(((CustomCronTrigger) obj).sequenceGenerator)));
    }

    @Override
    public int hashCode() {
        return this.sequenceGenerator.hashCode();
    }

    @Override
    public String toString() {
        return this.sequenceGenerator.toString();
    }
}

On the first interval the files get transferred properly and then deleted from source directory, though the log shows that only one file is being transferred. On successive intervals the files do not get transferred and get transferred only after some intervals. Reading the logs do not give any indication as to why the subsequent files are failing to get transferred on time. Below are the logs for the sftp.

*** 18 Nov 2013 11:49:00[L=INFO] [T=task-scheduler-1] (org.springframework.integration.file.FileReadingMessageSource:264 receive())
    Created message: [[Payload=/home/sftpUser/abc.csv][Headers={timestamp=1384755540001, id=fce1bea5-6444-4000-9b29-9a48e6027814}]]

*** 18 Nov 2013 11:50:00[L=INFO] [T=task-scheduler-2] (org.springframework.integration.file.FileReadingMessageSource:264 receive())
    Created message: [[Payload=/home/sftpUser/xyz.csv][Headers={timestamp=1384755600000, id=7a9c38b0-163c-473d-842b-58b41af8ad2d}]]

*** 18 Nov 2013 11:51:00[L=INFO] [T=task-scheduler-1] (org.springframework.integration.file.FileReadingMessageSource:264 receive())
    Created message: [[Payload=/home/sftpUser/def.csv][Headers={timestamp=1384755660001, id=3b10b954-3c16-4bf8-9b69-7fc213c68f37}]]

*** 18 Nov 2013 11:52:00[L=INFO] [T=task-scheduler-3] (org.springframework.integration.file.FileReadingMessageSource:264 receive())
    Created message: [[Payload=/home/sftpUser/ghi.csv][Headers={timestamp=1384755720028, id=e1031613-788d-45f9-a2ae-30f953832ff7}]]

Please suggest alternative's as I am at my wit's end with this problem.

Answer 1

It's not clear what you mean by "On successive intervals the files do not get transferred and get transferred only after some intervals".

Be aware that if you expect to transfer a file with the same name, it won't work because the default local filter will disallow the generation of a message for it. The upcoming 3.0 release has a new local-filter attribute to change that behavior, or you can use a gateway instead, as I suggested in this answer .