Statement.execute() method does not find the most specific method correctly.

Name: dsR10051 Date: 11/23/2001


The method of class java.beans.Statement
public void execute() throws Exception
does not find the most specific method correctly.
If target class declares two methods with the same name and type of
one parameter A or B, where A is a superclass of B,
and Statement is created with this target, method name and B type argument,
then execute() method can invoke method with A type argument on target.
This behavior depends on the order of method declaration.

Here is minimized test:
--- StatementTest_1 ---
import java.beans.*;

public class StatementTest_1 {

    public static void main (String[] args) {
        StatementTest_1 target = new StatementTest_1();
        String methodName = "method_1";
        B argument0 = new B();
        Object[] arguments = {argument0};
        Statement statement = new Statement(target, methodName, arguments);
        System.out.println("I.");
        try {
            System.out.print("Execute: ");
            statement.execute();
        } catch (Exception e) {
            e.printStackTrace();
        }
        System.out.print("Direct invocation: ");
        target.method_1(argument0);

        System.out.println("II.");
        System.out.println("Enother order of method declarations");

        methodName = "method_2";
        statement = new Statement(target, methodName, arguments);
        try {
            System.out.print("Execute: ");
            statement.execute();
        } catch (Exception e) {
            e.printStackTrace();
        }
        System.out.print("Direct invocation: ");
        target.method_2(argument0);
    }

    public void method_1 (A a) {
        System.out.println("method_1(A) called");
    }
    public void method_1 (B b) {
        System.out.println("method_1(B) called");
    }
        
    public void method_2 (B b) {
        System.out.println("method_2(B) called");
    }
    public void method_2 (A a) {
        System.out.println("method_2(A) called");
    }
}
--- A.java ---
public class A {
}
--- B.java ---
public class B extends A {
}

--- Output ---
/set/jdk-builds/JDK1.4.0beta2-b86/solaris/bin/java StatementTest_1
I.
Execute: method_1(A) called
Direct invocation: method_1(B) called
II.
Enother order of method declarations
Execute: method_2(B) called
Direct invocation: method_2(B) called
-----------------------
We can see that fist part of test failed: Statement.execute() method
should invoke method_1(B).

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