Connection with an excel document
Hi, I have a program that use a excel document as database, I get the data with the library JExcelAPI.
The application works fine, giving in the code the path of the document ("c:\book.xls"). When i use JWS i use the path "..//book.xls", but the program cant read from the excel, thats is located in the same directory of the proyect.
If the excel document is suppose to be in the server with the .jnlp file and the .jar of the program, What path i have to use?
[480 byte] By [
Atreidea] at [2007-11-27 1:12:16]
# 1
> Hi, I have a program that use a excel document as
> database, I get the data with the library JExcelAPI.
>
> The application works fine, giving in the code the
> path of the document ("c:\book.xls").
This is a fragile way to build up a path to a file.
Note that if you create a String of that, and print it
out, it writes..
"cook.xls"
(if you do not believe me, try it!)
It is always best to use the ..
http://java.sun.com/javase/6/docs/api/java/io/File.html#File(java.io.File, java.lang.String)
..constructor to build up the path to the file.
>.. When i use JWS
> i use the path "..//book.xls",
And what is that supposed to mean?
>..but the program cant
> read from the excel, thats is located in the same
> directory of the proyect.
>
> If the excel document is suppose to be in the server
> with the .jnlp file and the .jar of the program, What
> path i have to use?
Never heard of JExcelAPI before today, but a bit of
googling and a lot of guesswork suggests that if
you get get a valid URL to the spreadsheet, you
might use..
http://java.sun.com/javase/6/docs/api/java/net/URL.html#openStream()
..to get an input stream, then provide that input
stream to..
http://jexcelapi.sourceforge.net/resources/javadocs/2_6/docs/jxl/Workbook.html#getWorkbook(java.io.InputStream)
Message was edited by:
AndrewThompson64
# 2
Hi, thank you so much for the help but i have still problems.
I use the following code:
...
URL u= new URL("http://mywebpage.com/mydirectory/mybd.xls");
...
mybook = Workbook.getWorkbook(u.openStream());
...
Again it works fine if i execute the proyect from netbeans and directly from the .jar but when i execute the jnlp proyect, it dont read from the excel.
This is the jnlp:
<?xml version="1.0" encoding="utf-8"?>
<jnlp spec="1.0+"
codebase="http://localhost:8084/ProyectoJNLP/resources/" href="jnlp/prueba.jnlp">
<information>
<title>Grafica</title>
<vendor>Master</vendor>
<homepage href="http://www.unizar.es" />
<description>abc</description>
<description kind="short">abc</description>
<description kind="tooltip">abc</description>
<offline-allowed />
</information>
<resources>
<j2se version="1.4+" initial-heap-size="12m" max-heap-size="256m" />
<jar href="program/NubeDePuntos.jar" />
<jar href="program/lib/jcommon-1.0.6.jar"/>
<jar href="program/lib/jfreechart-1.0.3.jar"/>
<jar href="program/lib/swing-layout-1.0.jar"/>
</resources>
<application-desc main-class="Ventana" />
</jnlp>
Thanks for the help.
# 3
> Hi, thank you so much for the help but i have still
> problems.
...
> URL("http://mywebpage.com/mydirectory/mybd.xls");
...
> codebase="http://localhost:8084/ProyectoJNLP/resources/
Untrusted (sandboxed) web start apps. can 'phone home'
to the server that they came from, but not to other servers.
There are two ways to solve this:
1) Digitally sign the code and request all-permissions
in the JNLP file.
2) Put the JNLP launch file and the workbook
on the same server.
I guess the second is what you actually need.
Try putting a workbook on localhost and accessing
that.
By the way - it would help to get the exact ouput or
error message you are seeing - I am just guessing
what the problem is.
# 4
I dont get any error, the aplication has a few combos that are filled from the data of the excel, they just appear empty.
I use now this path for the excel archive, and still not working when i execute my web proyect:
u= new URL("http://localhost:8084/ProyectoJNLP/resources/jnlp/quimica.xls");
But, when i have the netbeans tomcat server running(after executing the proyect), If i execute the proyect of the .jar from netbeans the aplication reads the excel and works fine. If i double click the .jar of the jnlp proyect directly, it dont work.
Thank you for the help.
# 5
You mention you are note getting any errors.
What happens to exceptions that are thrown?
Does the code e.printStackTrace()?
Can you prepare a short example of
code that fails? It should be an SSCCE.
http://www.physci.org/codes/sscce.html
Do you have the Java console configured
to show the web start console every time
applications start?
# 6
Thanks, i open the console and get this exception:
java.net.MalformedURLException: no protocol: /jnlp/quimica.xls
at java.net.URL.<init>(Unknown Source)
at java.net.URL.<init>(Unknown Source)
at java.net.URL.<init>(Unknown Source)
at Modelo.abrirConexion(Modelo.java:25)
That line 25 is:
u= new URL("http://localhost:8084/ProyectoJNLP/resources/jnlp/quimica.xls");
# 7
Now i get this exception with the same URL:
Warning: Could not instantiate logger common.log.SimpleLogger using default
Warning: Error accessing system properties.
java.security.AccessControlException: access denied (java.util.PropertyPermission jxl.nowarnings read)
at java.security.AccessControlContext.checkPermission(Unknown Source)
at java.security.AccessController.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkPropertyAccess(Unknown Source)
at java.lang.System.getProperty(Unknown Source)
at java.lang.Boolean.getBoolean(Unknown Source)
# 8
> java.security.AccessControlException: access denied (java.util.PropertyPermission jxl.nowarnings read)For some reason (beyond the source of the excel document) this code needs 'full permissions', seemy second reply about code signing.
# 9
I have signed all the jars of the application and now it works fine.Thank you very much.
