CODEWITHSUNDEEP
javaweb-applications
akira
akira

Reputation: 1772

Reloading resources loaded by getResourceAsStream

Following best practices, I'm using Thread.currentThread().getContextClassLoader().getResourceAsStream to load resources in a web application (like text files or xml files), instead of going through the file API.

However, this has the disadvantage that if the resource changes on disk, a following call to getResourceAsStream keeps returning the old version indefinitely.

I would like it to pick up the new version though. In my debugger I see there's a simple HashMap called resourceEntries in the classLoader. Using reflection I've been able to remove a specific entry and this seems to work.

This method is however fragile.

Is there a more standard way to do this?

Upvotes: 12

Views: 4731

Answers (3)

Kai
Kai

Reputation: 849

i finally solved this problem by change the jar file name, every time i change the resource content, i change a new name with current timestamp

Upvotes: 0

Arjan Tijms
Arjan Tijms

Reputation: 38163

In addition to kschneid's answer which might work for Tomcat indeed, I wanted to add that for JBoss AS 5+ it already seems to work without needing any special tricks.

Caching of resources is probably class loader specific. The JBoss AS one either doesn't cache or is smart enough to see that the resource on disk has changed.

Upvotes: 1

kschneid
kschneid

Reputation: 5694

Try this:

ClassLoader ctxLoader = Thread.currentThread().getContextClassLoader();
URL resURL = ctxLoader.getResource(resName);
URLConnection resConn = resURL.openConnection();
resConn.setUseCaches(false);
InputStream resIn = resConn.getInputStream();
...

Upvotes: 6

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