FULL PRODUCT VERSION :
h:\>java -version
java version "1.6.0_01"
Java(TM) SE Runtime Environment (build 1.6.0_01-b06)
Java HotSpot(TM) Client VM (build 1.6.0_01-b06, mixed mode, sharing)


ADDITIONAL OS VERSION INFORMATION :

Microsoft Windows XP [Version 5.1.2600]


A DESCRIPTION OF THE PROBLEM :
This is not a swing problem, it is just that swing is the nearest matching subcategory it starts with pjavax !) and I had to choose one.

When running the javascript scripting engine, java Strings that are equal() but != and have been wrapped as javascript objects after being returned from a method call on another java object are NOT considered == whereas they should be.

However the same two java Strings, when wrapped using engine.put() do compare ==

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
run attached junit test

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
eq4 is true
ACTUAL -
eq4 is false

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.util.Arrays;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;
import junit.framework.*;
/*
 * StringEqualityTest.java
 * JUnit based test
 *
 * Created on 3 May 2007, 10:59
 */

/**
 *
 * @author bchapman
 */
public class StringEqualityTest extends TestCase {
    
    public StringEqualityTest(String testName) {
        super(testName);
    }

    public void testStringEquality() throws ScriptException {
        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("JavaScript");
        String alpha = "ABCD";
        String beta = new String(alpha);
        assertTrue(alpha.equals(beta));
        assertFalse(alpha == beta);
        engine.put("alpha",alpha);
        engine.put("beta", beta);
        engine.put("list", Arrays.asList(alpha,beta,beta.intern()));
        engine.eval("var eq1 = (alpha == beta);");
        engine.eval("alpha = list.get(0); beta = list.get(1);");
        engine.eval("var eq2 = (alpha == list.get(2));");
        engine.eval("var eq3 = alpha.equals(beta);");
        engine.eval("var eq4 = (alpha == beta);");
        assertTrue((Boolean)engine.get("eq1")); // == when non identical strings via engine.put()
        assertTrue((Boolean)engine.get("eq2")); // == when java returns identical Strings
        assertTrue((Boolean)engine.get("eq3")); // .equal() when java (List) returns non identical Strings
        assertTrue((Boolean)engine.get("eq4")); // fails == when java (List) returns non identical Strings
    }
}

---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
call intern() on any String return values from java methods that are exposed to javascript scripts.