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From David Smith <d...@cornell.edu>
Subject Re: access files from jsp
Date Tue, 29 Apr 2008 20:07:18 GMT
Yes, in general the <c:import url="http://remoteServer/path" /> would 
fetch the file via http protocol. The actual URL you'd use is dependent 
on the configuration of the remote server.

--David

henry human wrote:
> You gave me some idea and brought light to the issue!
> Thanks
>
> <c:import>
> url="http://remoteSystem.dns.com/http/path/to/file.txt
>   
>> var="fileContents" />
>>     
> Am I right about above, that you mean my JSP ask the
> tomcat on the remote machine and consequently the
> remote tomcat reads the file by means of the incoming
> url, from the d:\archive\files directory?
>
> Or you mean that the files are at remote web server
> directory ( f.i. \\tomcat\httpdirectory\files ) and my
> JSP request for them ?
>
>
> --- David Smith <dns4@cornell.edu> schrieb:
>
>   
>> So... the "remote file" is available to the local
>> system on a network 
>> drive. That's a fun one. There are a couple of
>> different ways to do this.
>>
>> 1. Using Windows fileshares
>>
>> Let me preface this by saying *I've* never done
>> this. The few times I've 
>> had a tomcat server on a Windows machine, it only
>> ever accessed local 
>> files. There are people on the list with way more
>> experience than I have.
>>
>> As I understand it, as long as tomcat is running
>> under a user account 
>> that has privileges to read the remote file, you
>> could use a UNC path 
>> with java standard file access classes and methods
>> to read the file. The 
>> mapped drive letter wouldn't work unless tomcat was
>> only running while 
>> you are logged in. In a jsp, this could be done with
>> a scriptlet:
>>
>> <!-- import your classes at the top of the jsp....
>> -->
>> <jsp:scriptlet>
>> try {
>> FileInputStream remoteFileReader = new
>> FileInputStream( 
>> "\\\\remoteServer\\archive\\files\\myFile.txt" ) ;
>> // do something with the file
>> } catch ( Exception e ) {
>> // do something if the access fails
>> } finally {
>> try {
>> remoteFileReader.close() ;
>> } catch ( Exception e ) {}
>> }
>> </jsp:scriptlet>
>>
>> It should be mentioned the system account most
>> services run under by 
>> default does not have any privilege to access remote
>> files via UNC path, 
>> so you'll have to customize your tomcat installation
>> a little. ... Or 
>> always be logged into the system and have it running
>> as you which isn't 
>> the most ideal method.
>>
>> 2. Using a webserver on the remote system
>>
>> This I have done and it's more platform independent.
>> Your jsp can 
>> request it from the remote server using standard
>> taglibs:
>>
>> (note standard.jar and jstl.jar must be in your
>> webapp's WEB-INF/lib 
>> directory)
>>
>> <!-- import the core taglib from jstl at the top of
>> the file. Docs for 
>> the jstl taglib can help with this -->
>>
>> <c:import
>>
>>     
> url="http://remoteSystem.dns.com/http/path/to/file.txt"
>   
>> var="fileContents" />
>> <!--.... Do something with the file contents, it'll
>> be available in the 
>> fileContents page context attribute.... -->
>>
>>
>> --David
>>
>> henry human wrote:
>>     
>>> Thanks David,
>>> I try to clarify my situation.
>>> I have a JSP running in local computer in tomcat.
>>>       
>> This
>>     
>>> JSP should read from a remote machine. The files
>>>       
>> are
>>     
>>> under d:\archive\files. These directory which
>>>       
>> provide
>>     
>>> a repository functionality could not be transfer
>>> somewhere else. The files “must be” saved there. 
>>> 1) Scennario one: The remote machine does not hava
>>>       
>> e
>>     
>>> webserver
>>> 2) Scenario two: a tomcat is running on remote
>>> computer 
>>>
>>> My questions:
>>> 1) Do I need the webserver at all to access
>>>       
>> remotely
>>     
>>> the files?
>>> 2) Is it poosile to access the data on d:\archive…
>>> without to put them in a webserver directory or
>>>       
>> not?
>>     
>>> If no, do I need configuration for the webserver
>>>       
>> (f.i.
>>     
>>> tomcat)to allow access to the files from outside? 
>>>
>>>
>>> --- David Smith <dns4@cornell.edu> schrieb:
>>>
>>>   
>>>       
>>>> Here's the picture you painted in the original
>>>>         
>> email
>>     
>>>> and I based my 
>>>> answer on:
>>>>
>>>> 1. You have a jsp file on a tomcat server which
>>>> needs to read 
>>>> information from a remote system
>>>> 2. The system containing the remote file has a
>>>> webserver you could put 
>>>> the file in.
>>>>
>>>> The c:import tag is a java standard tag library
>>>> (JSTL) tag used to 
>>>> import data form locations outside the jsp.  In
>>>>         
>> this
>>     
>>>> case, I'm saying 
>>>> you could request the file from the remote
>>>> webserver.  Google is your 
>>>> friend if you'd like more information.
>>>>
>>>> If I've misunderstood your environment, please
>>>> provide a *lot* more 
>>>> detail -- specifically more information regarding
>>>> the system the remote 
>>>> file reside's on (does it have a web server?).
>>>>
>>>> --David
>>>>
>>>> henry human wrote:
>>>>     
>>>>         
>>>>>   
>>>>>       
>>>>>           
>>>>>> Seems to me the simplest is the c:import tag
>>>>>>             
>> and
>>     
>>>>>>     
>>>>>>         
>>>>>>             
>>>>> sorry,I don't understand what you mean, could
>>>>>           
>> you
>>     
>>>>>       
>>>>>           
>>>> tell
>>>>     
>>>>         
>>>>> more detailed. Maybe a little code code, a
>>>>>           
>> sample,
>>     
>>>>>       
>>>>>           
>>>> etc
>>>>     
>>>>         
>>>>>   
>>>>>       
>>>>>           
>>>>>> fetch the file via http
>>>>>>     
>>>>>>         
>>>>>>             
>>>>> how?? 
>>>>>   
>>>>>       
>>>>>           
>>>>>> -- just my two cents.   You know more about
>>>>>>             
>> your
>>     
>>>>>> architecture and what's 
>>>>>> available than any of us.
>>>>>>     
>>>>>>         
>>>>>>             
>>>>> ??
>>>>> what
>>>>> should be configured in tomcat ?
>>>>> Do you mean that i do not need tomcat at all for
>>>>>       
>>>>>           
>>>> this
>>>>     
>>>>         
>>>>> scenario?
>>>>> I think it is not possible to read from the 
>>>>> hard disc directories f.i. d:\archive\files
>>>>>       
>>>>>           
>>>> without
>>>>     
>>>>         
>>>>> helps of a web server ?
>>>>>
>>>>> I am appreciated, if you get a sample, more
>>>>>       
>>>>>           
>>>> details!
>>>>     
>>>>         
>>>>>   
>>>>>       
>>>>>           
>>>>>> --David
>>>>>>
>>>>>> henry human wrote:
>>>>>>     
>>>>>>         
>>>>>>             
>>>>>>> Once again because there was a mistake in the
>>>>>>>       
>>>>>>>           
>>>>>>>               
>>>>>> first
>>>>>>             
> === message truncated ===
>
>
>
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