Error while trying to read file in jar

Question

I am trying to read an xsd file to validate schema.

My schema is in location x/y/z/test.xsd

My class reading this file is also in x/y/z/ReadSchema.java

Both there are packaged in my jar.

I am trying to read this file in ReadSchema.java like below where name is test.xsd But url is returned as null?

Anything I am doing wrong here ?

  private static URL getURLForName(String name) 
  {
      ClassLoader cl = Thread.currentThread().getContextClassLoader();

      URL url = cl.getResource(name);
      return url;
  }

rmalchow · Accepted Answer · 2013-04-22T08:19:08.817

2

the name you are using is wrong. keep in mind that:

getClass().getResource();

takes a name relative to the class, while

getClass().getClassLoader().getResource();

takes an absolute path.

EDIT: why i call it an absolute path

so, if your file is in yourjar.jar!x/y/z.txt and your class is x.y.Klass

then you could go for:

getClass().getResource("z.txt");

OR you could do:

getClass().getClassLoader().getResource("/x/y/z.txt");

edited Apr 22 '13 at 08:19

answered Apr 22 '13 at 08:05

rmalchow

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1

check this: http://stackoverflow.com/questions/14739550/what-is-the-difference-between-getclass-getclassloader-getresource-and-get – rmalchow Apr 22 '13 at 08:06
1

and this: http://stackoverflow.com/questions/676250/different-ways-of-loading-a-file-as-an-inputstream – rmalchow Apr 22 '13 at 08:06
I am not sure that I would call it an absolute path. – maba Apr 22 '13 at 08:14
see my edit ... absolute path (with the classpath) is the best name i could come up with. – rmalchow Apr 22 '13 at 08:19
why would you want to have the class of the Thread? just try a normal getClass(); – rmalchow Apr 22 '13 at 08:37
if this doesn't help, could you give us the package declaration of your class AND the structure in your jar? – rmalchow Apr 22 '13 at 08:38

mki · Answer 2 · 2013-04-22T08:22:49.363

Nothing wrong, but the test.xsd must be in your claspath. If it works in Eclipse and not in the jar, it mean that your MANIFEST.MF is not correct. Try to add the following line in the manifest and create the jar again :

Manifest-Version: 1.0
Class-Path: .

Here is the code one of my program :

URL config = SnapshotMigrationMain.class.getResource("/config_migration/log4jconfig.properties");

Of course you have to export your file in the jar or in a subdirectory relative to your jar.
With my example :
migration.jar
/config_migration/log4jConfig.properties

Error while trying to read file in jar

2 Answers2