A. Sundararajan's Weblog

import java.awt.*;
import javax.swing.*;

By default, BeanShell imports java.lang, java.util, java.io, java.net, java.awt, java.awt.event, javax.swing, javax.swing.event packages.

There is also (an experimental) import entire classpath option - which may be useful in interactive use.

import *

from java.util import *

import javax.swing.JFrame;

from javax.swing import JFrame

JF = javax.swing.JFrame
// prints "Class Identifier: javax.swing.JFrame"
print(JF)

from javax.swing import JFrame
JF = JFrame
print(JF)

f = new JFrame("hello");

from javax.swing import JFrame

# treat class name as a function name
# just call as though it is a function.

f = JFrame("hello")

f = new javax.swing.JFrame("hello");
f.setSize(100, 100);
f.setVisible(true);

from javax.swing import JFrame
f = JFrame("hello")
f.setSize(100, 100)
f.setVisible(1)

java.lang.System.exit(0)

from java.lang import System
System.exit(0)

f = new JFrame("hello");
f.setSize(100, 100);
// calls setVisible
f.visible = true;
// calls getTitle for "title" access
print(f.title);

from javax.swing import JFrame
f = JFrame("hello")
f.setSize(100, 100)
# calls setVisible
f.visible = 1;
# calls getTitle for "title" access
print(f.title);

f = new JFrame("hello");
// prints true
print(f instanceof JFrame);

from javax.swing import JFrame
f = JFrame("hello")
# prints "1"
print(isinstance(f, JFrame))

from java.lang import Byte
func(Byte(10))

from java.lang import Double
from java.lang import System

System.out.println(Double(33.33))

try {
  ioFunc();
} catch (IOException e) {
  print("caught it: " + e);
} catch (EOFException e1) {
  print("caught it: " + e1);
}

It is possible to omit the exception type in catch clause:

try {
  ioFunc();
} catch(e) {
  e.printStackTrace();
} 

from java.io import *
import sys

try:
  f = FileInputStream("myfile")
  c = f.read()
except FileNotFoundException:
  print(sys.exc_info())
except IOException:
  print(sys.exc_info())

s = new String[2];
print(s);

"jarray" module is used to create Java arrays. The jarray module exports two functions: array(sequence, type) and zeros(length, type). array will create a new array of the same length as the input sequence and will populate it with the values in sequence. zeros will create a new array of the given length filled with zeros (or null's if appropriate).

from java.lang import String
import jarray

s = jarray.zeros(2, String)
print(s)

from java.lang import String
import jarray

s = jarray.array(["hello", "world"], String)
print(s)

s = new String[2];
s[0] = "hello";
s[1] = "world";
print(s.length);
print(s[0]);
print(s[1]);

from java.lang import String
import jarray

s = jarray.zeros(2, String)
s[0] = "hello";
s[1] = "world";
print(len(s))
print(s[0])
print(s[1])

r = new Runnable() {
   run() {
     print("I'm runnable");
   }
};

print(r instanceof Runnable);
r.run();

class MyRunnable implements Runnable {
  public void run() {
    print("hello world");
  }
}

new MyRunnable().run();

from java.lang import Runnable
from java.lang import Thread

# just extend like a Python 
# super class
class MyRunnable(Runnable):
    def run(self):
       print("run called")

t = Thread(MyRunnable())
t.start()

When I tried this example, I got this error:
jython> Exception in thread "Thread-0" Traceback (innermost last):
(no code object) at line 0
AttributeError: abstract method "run" not implemented

This issue has been fixed. Please download the lastest binary and source.

import java.util.concurrent.Callable;

class MyClass implements Runnable, Callable {
  public void run() {
     print("run called");
  }

  public call() {
     print("call called");
  }
}

m = new MyClass();
print(m instanceof Runnable);
print(m instanceof Callable);
m.run();
m.call();

from java.util.concurrent import Callable
from java.lang import Runnable

class MyClass(Runnable, Callable):
  def run(self):
    print("run called")
  def call(self):
    print("call called")

m = MyClass()
# prints 1
print(isinstance(m, Runnable))
# prints 1
print(isinstance(m, Callable))
m.run()
m.call()

class MyHashtable extends Hashtable {
  // Override Hashtable.get method
  public get(key) {
    print("get called");
    // call super class method
    return super.get(key);
  }
}

m = new MyHashtable();
m.put("hello", "world");
print(m.get("hello"));

from javax.swing import JFrame

class MyFrame(JFrame):
  # override method
  def setVisible(self, flag):
    print("set visible")
    # call super class method
    JFrame.setVisible(self, flag)
 
f = MyFrame("hello")
print(isinstance(f, JFrame))
f.setVisible(1)

This issue has been fixed. Please download the lastest binary and source.