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JavaXT
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Jar ClassUsed to find entries in a jar file associated with a given class or package. The original motivation behind this class was to support a requirement to extract and update config files stored in Java packages. For console apps, the config file is stored in the jar (zip) file. For web apps, chances are that the package has been un-zipped and the config file is laying around on disk. This class was designed to support both use cases.
ConstructorsPublic MethodsgetFile( ) returns java.io.File Returns a java.io.File representation of the jar file or directory where the jar file has been extracted. getManifest( ) returns java.util.jar.Manifest Returns the Manifest file found in the "META-INF" directory. The Manifest file contains metadata for the jar file including version numbers, vendor name, etc. You can loop through properties in the Manifest like this:
java.io.File file = new java.io.File("/Drivers/h2/h2-1.3.162.jar");
java.util.jar.JarFile jar = new javaxt.io.Jar(file);
java.util.jar.Manifest manifest = jar.getManifest();
System.out.println("\r\nMain Attributes:\r\n--------------------------");
printAttributes(manifest.getMainAttributes());
System.out.println("\r\nOther Attributes:\r\n--------------------------");
java.util.Map<String, java.util.jar.Attributes> entries = manifest.getEntries();
java.util.Iterator<String> it = entries.keySet().iterator();
while (it.hasNext()){
String key = it.next();
printAttributes(entries.get(key));
System.out.println();
}
jar.close();
private static void printAttributes(java.util.jar.Attributes attributes){
java.util.Iterator it = attributes.keySet().iterator();
while (it.hasNext()){
java.util.jar.Attributes.Name key = (java.util.jar.Attributes.Name) it.next();
Object value = attributes.get(key);
System.out.println(key + ": " + value);
}
}
getVersion( ) returns String Returns the version number of the jar file, if available. Two different strategies are used to find the version number. First strategy is to parse the jar file manifest and return the value of the "Implementation-Version" or "Bundle-Version", whichever is found first. If no version information is found in the manifest, an attempt is made to parse the file name. Returns a null is no version information is available. getEntries( ) returns Entry[] Used to return a list of all the entries found in the jar file. getEntry( String Package, String Entry ) returns Entry Used to retrieve a single entry from the jar file.
getEntry( java.lang.Class Class ) returns Entry Used to retrieve a single entry from the jar file. getClasses( ) returns Class[] Returns all the classes in the jar file. Returns an empty array if the jar file has not been loaded or if there are no classes in the file. Static MethodsgetJars( java.lang.Package Package ) returns Jar[] Returns an array of files or directories associated with a given Package. This method should be used instead of new Jar(java.lang.Package). Public Classes |
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