从类路径加载 ResourceBundle

Question

I have two jar files. One of the jars needs to read language pack from another jar. Here is basic structure of both jars

jar1    
   |--com.example.BundleLoader 

jar2
   |--strings
         |--language.properties
         |--language_fr.properties

Language pack is on the classpath. In order to read language packs by the BundleLoader I am trying to use ResourseBundle in conjunction with ClassLoader. This is how I am attempting to do that

private ResourceBundle englishStrings = null;
private ResourceBundle frenchStrings = null;

System.out.println("About to load url from classpath for properties file " + bundleLocation);
URL url = ClassLoader.getSystemResource(bundleLocation);
bundleLocation = url.toString();
System.out.println("Ok loaded it");
System.out.println("url is " + (url == null ? "not available" : url.toString())); // Got the folder location

try {
    URL[] urls = { new URL(bundleLocation) }; // created array of ULRs to be loaded by URLClassLoader
    englishStrings = ResourceBundle.getBundle("validationStrings", Locale.getDefault(),
            new URLClassLoader(urls)); // Exception here
    frenchStrings = ResourceBundle.getBundle("validationStrings", Locale.FRENCH, 
            new URLClassLoader(urls));
} catch (MalformedURLException e1) {
    e1.printStackTrace();
}
<--End of Snippet-->

The Exception that I get is

java.lang.ExceptionInInitializerError
    at com.example.Model.model.dObject.doCommon(dObject.java:70)
    at com.example.Model.model.dObject.validate(dObject.java:42)
    at com.example.Model.model.test.dObjectTest.testChpValidate(dObjectTest.java:49)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: java.util.MissingResourceException: Can't find bundle for base name validationStrings, locale en_CA
    at java.util.ResourceBundle.throwMissingResourceException(ResourceBundle.java:1499)
    at java.util.ResourceBundle.getBundleImpl(ResourceBundle.java:1322)
    at java.util.ResourceBundle.getBundle(ResourceBundle.java:1028)
    at com.example.util.Strings.<init>(Strings.java:51)
    at com.example.util.Strings.<clinit>(Strings.java:26)
    ... 27 more

Basically I can't find bundles even though property files are in the folder. Have anyone ran into this? I assume that someone dealt with this before.

Thank you.

Answer 1

ResourceBundle.getBundle("validationStrings", Locale.FRENCH) will look in any JAR on the classpath for a file called validationStrings_fr.properties directly under the root directory. If it can't find that, it will try validationStrings.properties .

If you aren't able to change the structure of the language pack JAR, try replacing your entire second snippet with just

this.englishStrings = ResourceBundle.getBundle("strings.language");
this.frenchStrings = ResourceBundle.getBundle("strings.language", Locale.FRENCH);

The englishStrings line will look for files strings/language_en_CA.properties (assuming your default locale is en_CA ), and then fall back to strings/language.properties when it cannot find that. The frenchStrings line will look for strings/language_fr.properties .