How do I check for file existence using

[Anon Anon]

Hi All,

 

I'm having trouble getting the <util:available> tag returning me a 'true' condition when a file is being found (which is actually the ability to execute a set of commands within the utl tag, from what I can gather).

 

What I'm trying to do is poll a fileshare directory for the existence of a file, and when the file existence is detected, exit the polling loop (and carry on with the rest of the GEL).

 

The problem I'm trying to solve is a file doesn't exist error when trying to open a file using the <file:readFile>. To make this issue most interesting, only our production environment exhibits the issue of not finding this file on the fileshare using the <file:readFile> tag (and if I simply 'retry' the process after 2-8 minutes, the script finds the file just fine, without any polling logic needed).

 

Two snippets below, namespaces and polling loop. The loop does iterate, but the commands within the util:available doesn't ever get executed. The loop does iterate, and sleeps ok with the said milliseconds, but the file is never 'seen' by the util:available. Funny thing is, the file is actually there......

 

What am I doing wrong? I've tried with and without the "file://" prefic for the uri.

 

The fileshare directory is of the form /fs0/clarity1/files/filestore/clarity/

 

(I'm on v13.1, CA on demand).

 

Regards,

Sam.

======================

 

<gel:script

    xmlns:core="jelly:core"

    xmlns:file="jelly:com.niku.union.gel.FileTagLibrary"

    xmlns:gel="jelly:com.niku.union.gel.GELTagLibrary"

    xmlns:soap="jelly:com.niku.union.gel.SOAPTagLibrary"

    xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"

    xmlns:sql="jelly:sql"

    xmlns:util="jelly:util"

    xmlns:xog="http://www.niku.com/xog"

>

 

<!-- snip -->

<core:set value="false" var="errorFlag"/>

<!-- snip -->

 

 

<!-- check for file existence a number of times, before timing out if required-->

<!-- CA couldn't resolve this timing issue for us, which only happens in PROD, not in dev or test yet. -->

<core:if test="${errorFlag==false}">

    <core:set value="0" var="v_file_exists"/>

    <core:set value="0" var="v_counter"/>

    <core:set value="24" var="v_counter_limit"/>

    <core:set value="500" var="v_sleep_ms"/>

    <core:while test="${v_counter le v_counter_limit and v_file_exists eq 0}">

        <core:catch var="v_exception">

            <util:available uri="file://${v_fileStore}${file}">

                <gel:log category="File" level="INFO">File available returned true on iteration ${v_counter}.</gel:log>

                <core:set value="1" var="v_file_exists"/>

            </util:available>

        </core:catch>

        <core:choose>

            <core:when test="${v_exception!=null}">

                <gel:log category="File" level="WARN">Unable to test for file existence:${file} from directory:${v_fileStore} Exception:${v_exception}.</gel:log>

                <core:set value="true" var="errorFlag"/>

            </core:when>

            <core:when test="${v_counter lt v_counter_limit}">

                <gel:log category="File" level="INFO">File polling iteration ${v_counter}, sleeping...</gel:log>

                <util:sleep millis="${v_sleep_ms}"/>

            </core:when>

            <core:when test="${v_counter ge v_counter_limit}">

                <core:set value="Polled too many times / Timed out polling for file existence:${file} from directory:${v_fileStore} Iteration:(${v_counter}) out of (${v_counter_limit}), waiting (${v_sleep_ms/1000}) seconds between each." var="v_exception"/>

                <gel:log category="File" level="WARN">${v_exception}</gel:log>

                <core:set value="true" var="errorFlag"/>

            </core:when>

            <core:otherwise>

                <gel:log category="File" level="WARN">Shouldnt ever be here ${v_counter}.</gel:log>

            </core:otherwise>

        </core:choose>

        <core:set value="${v_counter+1}" var="v_counter"/>

    </core:while>

</core:if>

 

<!-- open the file from the windows directory, and load to a gel variable. -->

<core:if test="${errorFlag==false}">

    <core:catch var="v_exception">

        <file:readFile

        delimiter="~"

        embedded="false"

        escapeText="true"

        fileName="${v_fileStore}${file}"

        var="v_file_in_mem"/>

    </core:catch>

    <core:choose>

        <core:when test="${v_exception!=null}">

            <gel:log category="File" level="ERROR">Unable to read file:${file} from directory:${v_fileStore} Exception:${v_exception}.</gel:log>

            <core:set value="true" var="errorFlag"/>

        </core:when>

        <core:otherwise>

            <core:set value="${v_file_in_mem.size()}" var="v_file_in_mem_size"/>

            <core:set value="0" var="v_count"/>

            <core:if test="${DEBUG>0}">

                <gel:log category="File" level="INFO">File has ${v_file_in_mem_size} rows.</gel:log>

            </core:if>

        </core:otherwise>

    </core:choose>

</core:if>

[System]

Hi All,

 

Any ideas here for Sam?

 

Thanks!

Chris

[Eugene Greiff]

This works on my machine.  For file you need file:/// to get to the top of the disk.

 

<gel:script

    xmlns:core="jelly:core"

    xmlns:log="jelly:log"

    xmlns:util="jelly:util"

    xmlns:gel="jelly:com.niku.union.gel.GELTagLibrary"

    xmlns:xsd="http://www.w3.org/2001/XMLSchema"

    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

 

    <gel:out>Start this Script</gel:out>

  

    <core:set var="fileName" value="C:\Temp\ProjectsService.cs"/>

  

    <util:available uri="file:///${fileName}">

        <gel:out>This URL is available</gel:out>

    </util:available>

  

    <core:new className="java.io.File" escapeText="false" var="fileTest" >

        <core:arg type="java.lang.String" value="${fileName}" />

    </core:new>

  

    <core:if test="${fileTest.exists()}">

            <gel:out>This file exits ${fileName}</gel:out>

    </core:if>

  

    <gel:out>End this Script</gel:out>

 

</gel:script>

 

V/r,

Gene

[Anon Anon]

Beware of empty/zero-sized-files.

[Eugene Greiff]

Very good point:

 

<core:if test="${fileTest.exists()}">

    <gel:out>This file exits ${fileName}</gel:out>

    <core:if test="${fileTest.length() == 0}">

        <gel:out>The file is empty</gel:out>

    </core:if>

    <core:if test="${fileTest.length() > 0}">

        <gel:out>The file is not empty</gel:out>

    </core:if>

</core:if>

 

V/r,

Gene

[Anon Anon]

gcubed, may I ask which version you got this to work on?

 

It may be that util:available is not available on my v13.1... (as it doesn't seem to be there in the ca support docs for that version, does appear to be there in v13.3)

[Eugene Greiff]

I don't have a 13.1 system but it worked on a 13.2 and 13.3 system.  My 13.3 system is OnDemand.  I ran this script.

 

<?xml version="1.0" encoding="utf-8"?>

<gel:script

    xmlns:core="jelly:core"

    xmlns:log="jelly:log"

    xmlns:util="jelly:util"

    xmlns:gel="jelly:com.niku.union.gel.GELTagLibrary"

    xmlns:xsd="http://www.w3.org/2001/XMLSchema"

    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

 

    <gel:log>Start this Script</gel:log>

   

    <core:set var="fileName" value="/fs0/clarity1/share/UrlOutput.txt"/>

   

    <util:available uri="file://${fileName}">

        <gel:log>This URL is available</gel:log>

    </util:available>

   

    <core:new className="java.io.File" escapeText="false" var="fileTest" >

        <core:arg type="java.lang.String" value="${fileName}" />

    </core:new>

   

    <core:if test="${fileTest.exists()}">

            <gel:log>This file exits ${fileName}</gel:log>

            <core:if test="${fileTest.length() == 0}">

                <gel:log>The file is empty</gel:log>

            </core:if>

            <core:if test="${fileTest.length() > 0}">

                <gel:log>The file is not empty</gel:log>

            </core:if>

    </core:if>

   

    <gel:log>End this Script</gel:log>

 

</gel:script>

 

And here is the log for it:

 

 

The is an option to restrict gel tags, I not sure what it restricts but you could ask the OnDemand group, via Support if that is turn on in your instance.

 

V/r,

Gene

[Anon Anon]

Try <util:available file="${v_fileStore}${file}">

[Anon Anon]

In answer to my own post (weird!), what I ended up doing was to use the exception of the <file:readFile> to drive the polling logic. So I've replaced my above GEL snippet with the below.

 

I was also suggested by CA Support that util:available may not be available on v13.1 - and I took their word for it.

 

Gel below.

 

Thanks to All for looking into it!

 

Sam.

 

=====

 

<!-- check for file existence a number of times, before timing out if required-->

<core:if test="${errorFlag==false}">

    <core:set value="0" var="v_file_exists"/>

    <core:set value="0" var="v_counter"/>

    <core:set value="72" var="v_counter_limit"/>

    <core:set value="10000" var="v_sleep_ms"/> <!-- v_counter_limit multiplied by v_sleep_ms equals total timeout -->

    <core:while test="${v_counter le v_counter_limit and v_file_exists eq 0}">

        <core:catch var="v_exception">

            <file:readFile

            delimiter="~"

            embedded="false"

            escapeText="true"

            fileName="${v_fileStore}${file}"

            var="v_file_in_mem"/>

        </core:catch>

        <core:choose>

            <core:when test="${v_exception == null and v_counter lt v_counter_limit}">

                <gel:log category="File" level="INFO">File found on iteration ${v_counter}.</gel:log>

                <core:set value="1" var="v_file_exists"/>

                <core:set value="${v_file_in_mem.size()}" var="v_file_in_mem_size"/>

                <core:if test="${DEBUG>0}">

                    <gel:log category="File" level="INFO">File has ${v_file_in_mem_size} rows.</gel:log>

                </core:if>

            </core:when>

            <core:when test="${v_exception != null and v_counter lt v_counter_limit}">

                <gel:log category="File" level="INFO">File not found on polling iteration ${v_counter}, sleeping for another (${v_sleep_ms/1000}) seconds... (Exception:${v_exception}).</gel:log>

                <util:sleep millis="${v_sleep_ms}"/>

            </core:when>

            <core:when test="${v_counter ge v_counter_limit}">

                <core:set value="Polled too many times / Timed out polling for file existence:${file} from directory:${v_fileStore} Iteration:(${v_counter}) out of (${v_counter_limit}), waiting (${v_sleep_ms/1000}) seconds between each." var="v_exception"/>

                <gel:log category="File" level="WARN">${v_exception}</gel:log>

                <core:set value="true" var="errorFlag"/>

            </core:when>

            <core:otherwise>

                <gel:log category="File" level="WARN">Shouldn't ever be here ${v_counter}.</gel:log>

            </core:otherwise>

        </core:choose>

        <core:set value="${v_counter+1}" var="v_counter"/>

    </core:while>

</core:if>