method.java

一个开源的JAVA虚拟机

/*
    libaegisvm - The Aegis Virtual Machine for executing Java bytecode
    Copyright (C) 2001-2002  Philip W. L. Fong

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

*/

package java.lang.reflect;

public final class Method extends AccessibleObject implements Member {
    private Class declaringClass;     // The VM depends on the object
    private int id;                   // layout of the class.
    private Method(Class declaringClass, int id) {
	this.declaringClass = declaringClass;
	this.id = id;
    }
    public Class getDeclaringClass() {
	return declaringClass;
    }
    public native String getName();
    private native String getDescriptor();
    public native int getModifiers();
    public Class getReturnType() {
	return aegis.Reflect.getReturnType(declaringClass, getDescriptor());
    }
    public Class[] getParameterTypes() {
	return aegis.Reflect.getParameterTypes(declaringClass,getDescriptor());
    }
    private native int getExceptionsCount();
    private native String getException(int id);
    public Class[] getExceptionTypes() {
	int count = getExceptionsCount();
	Class[] exceptions = new Class[count];
	for (int i = 0; i < count; i++) {
	    try {
		String exception = getException(i);
		exceptions[i] =
		    Class.forName(exception.replace('/', '.'), false,
				  declaringClass.getClassLoader());
	    } catch (ClassNotFoundException ex) {
		throw new NoClassDefFoundError();
	    }
	}
	return exceptions;
    }
    public boolean equals(Object obj) {
	if (! (obj instanceof Method))
	    return false;
	Method M = (Method) obj;
	return declaringClass == M.declaringClass && id == M.id;
    }
    public int hashCode() {
	return declaringClass.hashCode() ^ getName().hashCode();
    }
    public String toString() {
	String S = 
	    Modifier.toString(getModifiers()) +
	    getReturnType().getName() + ' ' +
	    declaringClass.getName() + '.' +
	    getName() + '(';
	Class[] params = getParameterTypes();
	if (params.length > 0) {
	    S += params[0].getName();
	    for (int i = 1; i < params.length; i++)
		S += ',' + params[i].getName();
	}
	S += ')';
	Class[] exceptions = getExceptionTypes();
	if (exceptions.length > 0) {
	    S += " throws " + exceptions[0].getName();
	    for (int i = 1; i < exceptions.length; i++)
		S += ',' + exceptions[i].getName();
	}
	return S;
    }
    /**
     * \todo Accessibility check.
     */
    public Object invoke(Object obj, Object[] args)
	throws IllegalAccessException,
	       IllegalArgumentException,
	       InvocationTargetException {
	if (!Modifier.isStatic(getModifiers())) {
	    if (obj == null)
		throw new NullPointerException();
	    if (! declaringClass.isInstance(obj))
		throw new IllegalArgumentException();
	}
	// fix me: accessibility check goes here
	args = aegis.Reflect.widen(args, getParameterTypes());
	return invoke(declaringClass, id, obj, args);
    }
    private static native Object invoke(Class clazz,
					int i,
					Object obj,
					Object[] args)
	throws InvocationTargetException;
}