com.google.gwt.dev.shell.designtime.MethodAdaptor.java Source code

Introduction

Here is the source code for com.google.gwt.dev.shell.designtime.MethodAdaptor.java

Source

/*******************************************************************************
 * Copyright 2011 Google Inc. All Rights Reserved.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *******************************************************************************/
package com.google.gwt.dev.shell.designtime;

import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;

/**
 * Provides a common adaptor interface for Methods and Constructors.
 */
public class MethodAdaptor {
    private final Constructor<?> constructor;
    private final Class<?> declaringClass;
    private final int hashCode;
    private final Method method;
    private final String name;
    private final boolean needsThis;
    private final Class<?>[] paramTypes;
    private final Class<?> returnType;

    public MethodAdaptor(Constructor<?> c) {
        constructor = c;
        method = null;
        name = c.getName();
        needsThis = false;
        paramTypes = c.getParameterTypes();
        returnType = declaringClass = c.getDeclaringClass();
        hashCode = c.hashCode();
    }

    public MethodAdaptor(Method m) {
        constructor = null;
        declaringClass = m.getDeclaringClass();
        method = m;
        name = m.getName();
        needsThis = !Modifier.isStatic(m.getModifiers());
        paramTypes = m.getParameterTypes();
        returnType = m.getReturnType();
        hashCode = method.hashCode();
    }

    @Override
    public boolean equals(Object o) {
        if (!(o instanceof MethodAdaptor)) {
            return false;
        }

        MethodAdaptor other = (MethodAdaptor) o;
        if (constructor != null) {
            return constructor.equals(other.constructor);
        } else if (method != null) {
            return method.equals(other.method);
        } else {
            throw new RuntimeException("constructor and method are null");
        }
    }

    public Class<?> getDeclaringClass() {
        return declaringClass;
    }

    public String getName() {
        return name;
    }

    public Class<?>[] getParameterTypes() {
        return paramTypes;
    }

    public Class<?> getReturnType() {
        return returnType;
    }

    public AccessibleObject getUnderlyingObject() {
        return (method != null) ? method : constructor;
    }

    @Override
    public int hashCode() {
        return hashCode;
    }

    public Object invoke(Object obj, Object... args)
            throws InstantiationException, InvocationTargetException, IllegalAccessException {
        if (method != null) {
            return method.invoke(obj, args);
        } else if (constructor != null) {
            return constructor.newInstance(args);
        } else {
            throw new RuntimeException("Nothing to invoke");
        }
    }

    /**
     * Indicates whether or not a "this" object is required to invoke the Method
     * or Constructor.
     */
    public boolean needsThis() {
        return needsThis;
    }

    @Override
    public final String toString() {
        return (method != null) ? method.toString() : constructor.toString();
    }
}