Name: ngR10089 Date: 01/27/2004


 
javac (jdk1.5.0-b35) doesn't allow arrays of generic types.

The latest spec of "Adding Generics to the Java Programming Language: Public
Draft Specification, Version 2.0" say nothing about forbidden generic type
array creation.
More over it reads:

    5.3 Array Creation Expressions

    The element type in an array creation expression is a fully parameterized
    type. Creating an array whose element type is a type variable generates an
    unchecked warning at compile-time.
    
    Syntax (see JLS, Sec. 15.10)

    ArrayCreationExpression ::= new PrimitiveType DimExprs DimsOpt
                              | new ClassOrInterfaceType DimExprs DimsOpt
                              | new PrimitiveType Dims ArrayInitializer
                              | new ClassOrInterfaceType Dims ArrayInitializer


However javac (jdk1.5.0-b35) reports errors compiling test below.

> java -version
java version "1.5.0-beta2"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0-beta2-b35)
Java HotSpot(TM) Client VM (build 1.5.0-beta2-b35, mixed mode)
novo41%

> javac -d . -source 1.5 expr67201.java
expr67201.java:27: arrays of generic types are not allowed
        expr67201a<Integer>[] vi = new expr67201a<Integer>[10];
                           ^
expr67201.java:27: arrays of generic types are not allowed
        expr67201a<Integer>[] vi = new expr67201a<Integer>[10];
                                   ^
expr67201.java:30: arrays of generic types are not allowed
        expr67201a<String>[] vs = {new expr67201a<String>("Test0"),
                          ^
3 errors
>

--------------- expr67201.java-------------
package javasoft.sqe.tests.lang.expr672.expr67201;
import java.io.PrintStream;

class expr67201a<A>{
    A value;
    expr67201a(A value) {
        this.value = value;
    }
    expr67201a() {
    }
}

public class expr67201 {
    public static void main(String argv[]) {
        System.exit(run(argv, System.out) + 95/*STATUS_TEMP*/);
    }
    public static int run(String argv[],PrintStream out) {
        boolean result = true;
        expr67201a<Integer>[] vi = new expr67201a<Integer>[10];
        for(int i = 0; i < 2; i++)
            vi[i] = new expr67201a<Integer>(new Integer(i));
        expr67201a<String>[] vs = {new expr67201a<String>("Test0"),
                new expr67201a<String>("Test1")};
        for(int i = 0; i < 2; i++)
            if(vi[i].value.intValue() != i || !vs[i].value.equals("Test" + i))
                result = false;
        if(result)
            return 0/*STATUS_PASSED*/;
        return 2/*STATUS_FAILED*/;
    }
}
---------------------------------------

Some new JCK tests fail due to this bug.


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