Jython - Importing Java Libraries


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One of the most important features of Jython is its ability to import Java classes in a Python program. We can import any java package or class in Jython, just as we do in a Java program. The following example shows how the java.util packages are imported in Python (Jython) script to declare an object of the Date class.

from java.util import Date
d = Date()
print d

Save and run the above code as UtilDate.py from the command line. Instance of the current date and time will be displayed.

C:\jython27\bin>jython UtilDate.py
Sun Jul 09 00:05:43 IST 2017

The following packages from the Java library are more often imported in a Jython program mainly because standard Python library either does not have their equivalents or are not as good.

  • Servlets
  • JMS
  • J2EE
  • Javadoc
  • Swing is considered superior to other GUI toolkits

Any Java package for that matter can be imported in a Jython script. Here, the following java program is stored and compiled in a package called foo.

package foo;
public class HelloWorld {
   public void hello() {
      System.out.println("Hello World!");
   }
   public void hello(String name) {
      System.out.printf("Hello %s!", name);
   }
}

This HelloWorld.class is imported in the following Jython Script. Methods in this class can be called from the Jython script importex.py.

from foo import HelloWorld
h = HelloWorld()
h.hello()
h.hello("TutorialsPoint")

Save and execute the above script from the command line to get following output.

C:\jython27\bin>jython importex.py
Hello World!
Hello TutorialsPoint!
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