spring integration dynamic filter based on the current Date

Question

I am trying to use ftp-inbound-adapter to poll files based on the the current date.And my inbound adapter uses a filter which refers to bean myfilter .The problem here is the current date is initailized at the startup and is not been processed dynamically..I would like to get the current date for every new message

    <int-ftp:inbound-channel-adapter id="ftpInbound"
                    channel="ftpChannel"
                    session-factory="ftpsClientFactory"
                    filter="myFilter"
    </int-ftp:inbound-channel-adapter>

    <bean id="myFilter" class="org.springframework.integration.ftp.filters.FtpRegexPatternFileListFilter" scope="prototype">
        <constructor-arg value="#{T(java.time.LocalDateTime).now().format(T(java.time.format.DateTimeFormatter).ofPattern('MMddyy'))}.(xls|xlsx)"/>
        <aop:scoped-proxy/>
        </bean>

UPDATE

I changed from this

    <bean id="currentDate" class="java.util.Date" factory-bean="fastDateFormat"
        scope="prototype" factory-method="format" >
        <aop:scoped-proxy/> 
        <constructor-arg>
            <bean class="java.util.Date" />
        </constructor-arg>
    </bean>


<bean id="myFilter" class="org.springframework.integration.ftp.filters.FtpRegexPatternFileListFilter" scope="prototype">
        <constructor-arg value="#{currentDate}.(xls|xlsx)"/>
        </bean>

And my inbound adapter uses a filter which refers to bean myFilter .. The problem here is the current date is initailized at the startup and is not been processed dynamically..I would like to get the current date for every new message

change your filter bean to 'prototype' as well – Ahsan Shah Dec 18 '18 at 04:51 — Ahsan Shah, Dec 18 '18 at 04:51
@AhsanShah: I tried that..It isnt working. – codinginprogress Dec 18 '18 at 14:50 — codinginprogress, Dec 18 '18 at 14:50

Artem Bilan · Accepted Answer · 2018-12-18T16:54:01.130

2

This impossible with your current configuration because that filter is just a singleton bean created only once at start up pulling that your currentDate for injection only once as well.

You may try to add <aop:scoped-proxy/> into your currentDate bean definition, though: https://docs.spring.io/spring/docs/5.1.3.RELEASE/spring-framework-reference/core.html#beans-factory-scopes-other-injection, but I would suggest to inject BeanFactorty into your filter and call getBean("currentDate", Date.class) every time you need a new instance of that prototype.

UPDATE

You inject BeanFactory into your filter instead of that currentDate bean. And then when filter logic is called you do Date currentDate = this.beanFactory.getBean("currentDate", Date.class);.

UPDATE2

Here is what I think should work for you:

public class DynamicRegexPatternFilter extends AbstractFileListFilter<File> {

    @Autowired
    private BeanFactory beanFactory;

    @Override
    public boolean accept(File file) {
        return Pattern.compile(this.beanFactory.getBean("currentDate", String.class) + ".(xls|xlsx)")
                .matcher(file.getName())
                .matches();
    }

}

edited Dec 18 '18 at 16:54

answered Dec 17 '18 at 21:50

Artem Bilan

113,505
11
91
118

I tried to add into my currentDate bean.. Its still loading date at the start up . What would be the other option apart from the current configuration that i am using? – codinginprogress Dec 18 '18 at 14:45
See an UPDATE in my answer, please. – Artem Bilan Dec 18 '18 at 14:55
Show your filter code and I’ll modify it respectively – Artem Bilan Dec 18 '18 at 15:02
Please, edit your question with proper code formatting. It's not readable in the comments – Artem Bilan Dec 18 '18 at 15:07
I don't see any `currentDate` bean reference in your `myFilter` bean definition. Also I asked you to place `` for the `currentDate`, not `filter` bean. Also the `prototype` is not going to work for the `filter` bean. It is indeed going to be instantiated only once for that ` – Artem Bilan Dec 18 '18 at 15:30
Updated the question – codinginprogress Dec 18 '18 at 15:38
No, that `` still not going to work. You resolve a bean really only once at start up. That expression is not evaluated every time. As I said: you need a custom `FileListFilter` to build a pattern in Java code for every incoming file. – Artem Bilan Dec 18 '18 at 15:43
And the custom class has something like public class FileNamePattern { @Autowired BeanFactory beanFactory; public FileNamePattern() { Date date=this.beanFactory.getBean("currentDate", Date.class); } } – codinginprogress Dec 18 '18 at 15:59
Sounds much better! – Artem Bilan Dec 18 '18 at 16:17
:But how is this date mapped back to myFilter. And how can we use this date value back in our filter? .. I am not able to follow on the link part..How these things work in the background – codinginprogress Dec 18 '18 at 16:48
Please, find an UPDATE2 in my answer. – Artem Bilan Dec 18 '18 at 16:54
– codinginprogress Dec 18 '18 at 18:06
I think you can't change system date for already ran JVM. That's already out of scope of our current problem... – Artem Bilan Dec 18 '18 at 18:08

score 0 · Answer 2 · answered Sep 21 '22 at 14:55

You can make custom filter. Implement FileListFilter and override filterFiles method which takes input argument as array of LsEntry. LsEntry is nothing but a small metadata object of a File present at (S)FTP. It comprises of File Name and the date on which it was modified.

@Override
public List<LsEntry> filterFiles(LsEntry[] files) {
    List<LsEntry> result = new ArrayList<LsEntry>();
    Vector<LsEntry> list = new Vector<LsEntry>();
    Collections.addAll(list, files);
    ChannelSftp.LsEntry lastModifiedEntry = Collections.max(list,
            (Comparator.comparingInt(entry -> entry.getAttrs().getMTime())));
    result.add(lastModifiedEntry);
    return result;
}

Reference: https://stackoverflow.com/a/60635859/11325128

spring integration dynamic filter based on the current Date

2 Answers2