114918 - The method overloading of liveconnect can not differentiate between different types of numbers

Status: VERIFIED WORKSFORME

(Core Graveyard :: Java: Live Connect, defect)

Description

[Xiaobin Lu]

From Bugzilla Helper:
User-Agent: Mozilla/5.0 (Windows; U; WinNT4.0; en-US; rv:0.9.4) Gecko/20011128
Netscape6/6.2.1
BuildID:    20011212

This is my applet code. I would call these applet method from JS.
However, whenever I call setValue("test1", 1), it always calls setValue("test1",
1.0) method.

public class JApplet_TEST extends JApplet {
    public void setValue (String par, int val) {
        System.out.println("par="+par+ "  int val="+val);
    }
    public void setValue (String par, boolean val) {
        System.out.println("par="+par+ "  boolean val="+val);
    }
    public void setValue (String par, double val) {
        System.out.println("par="+par+ "  double val="+val);
    }
    public void setValue (String par, String val) {
        System.out.println("par="+par+ "   String val="+val);
    }
}

I digged into the code and found that when the liveconnect engine tries to
reflect these java methods, it can not differentiate between data types because
Javascript defines data types as below.

typedef enum JSJType {
      JSJTYPE_VOID,                /* undefined */
      JSJTYPE_BOOLEAN,             /* boolean */
      JSJTYPE_NUMBER,              /* number */
      JSJTYPE_STRING,              /* string */
      JSJTYPE_NULL,                /* null */
      JSJTYPE_JAVACLASS,           /* JavaClass */
      JSJTYPE_JAVAOBJECT,          /* JavaObject */
      JSJTYPE_JAVAARRAY,           /* JavaArray */
      JSJTYPE_JSARRAY,             /* JS Array */
      JSJTYPE_OBJECT,              /* Any other JS Object, including functions */
      JSJTYPE_LIMIT
  } JSJType;
Those types do not differentiate number types in more details. This may cause
problem sometimes.
 


Reproducible: Always
Steps to Reproduce:
1. Open the URL specified.
2. Click the Liveconnect Test 1 and liveconnect Test 3.
3. Open Java console, you should be able to see some messages printed out.
Notice that liveconnect Test3 uses the method setValue(String, double) to print.

Actual Results:  It calls  setValue(String, double)

Expected Results:  It calls  setValue(String, int)

Comment 1

[Boris Zbarsky [:bzbarsky]]

confirming, but the problem is that ECMAScript has no concept of Integer vs
Float numbers, if I understand correctly....

Comment 2

[Phil Schwartau]

Reassigning to Patrick; cc'ing Brendan, Roger -

Comment 3

[Patrick C. Beard]

Yes, the current JavaScript engine is based on the ECMAScript 3 
standard, and there is no other kind of number other than double-
precision floating point. However, there is a mechanism called "explicit 
resolution" that can be used to select a specific method.

Comment 4

[Xiaobin Lu]

Patrick:
   Can you tell me how to use explict resolution method? Thanks!

Comment 5

[Patrick C. Beard]

If you change your test3 function to, you can select the method with the int 
parameter:

function test3() {
    document.test["setValue(java.lang.String,int)"]("test 3", 3);
}

In general, you look up the method you want with a fully qualified set of 
method signatures. All of the primitive type names are as they are defined 
in Java, byte, short, int, long, float, double, and boolean. For object 
parameters, use the fully qualified class name. No spaces between 
signatures, just comma delimited.

Comment 6

[Phil Schwartau]

Marking Verified - 

Xiaobin, if this is still a problem, please reopen this bug; thanks -

Comment 7

[Xiaobin Lu]

Ok for me!