Method.java

/*******************************************************************************
 * Copyright 2011 See AUTHORS file.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * 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.badlogic.gdx.utils.reflect;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Modifier;

/**
 * Provides information about, and access to, a single method on a class or
 * interface.
 * 
 * @author nexsoftware
 */
public final class Method {

    private final java.lang.reflect.Method method;

    Method(java.lang.reflect.Method method) {
        this.method = method;
    }

    /** Returns the name of the method. */
    public String getName() {
        return method.getName();
    }

    /**
     * Returns a Class object that represents the formal return type of the
     * method.
     */
    public Class getReturnType() {
        return method.getReturnType();
    }

    /**
     * Returns an array of Class objects that represent the formal parameter
     * types, in declaration order, of the method.
     */
    public Class[] getParameterTypes() {
        return method.getParameterTypes();
    }

    /**
     * Returns the Class object representing the class or interface that
     * declares the method.
     */
    public Class getDeclaringClass() {
        return method.getDeclaringClass();
    }

    public boolean isAccessible() {
        return method.isAccessible();
    }

    public void setAccessible(boolean accessible) {
        method.setAccessible(accessible);
    }

    /** Return true if the method includes the {@code abstract} modifier. */
    public boolean isAbstract() {
        return Modifier.isAbstract(method.getModifiers());
    }

    /**
     * Return true if the method does not include any of the {@code private},
     * {@code protected}, or {@code public} modifiers.
     */
    public boolean isDefaultAccess() {
        return !isPrivate() && !isProtected() && !isPublic();
    }

    /** Return true if the method includes the {@code final} modifier. */
    public boolean isFinal() {
        return Modifier.isFinal(method.getModifiers());
    }

    /** Return true if the method includes the {@code private} modifier. */
    public boolean isPrivate() {
        return Modifier.isPrivate(method.getModifiers());
    }

    /** Return true if the method includes the {@code protected} modifier. */
    public boolean isProtected() {
        return Modifier.isProtected(method.getModifiers());
    }

    /** Return true if the method includes the {@code public} modifier. */
    public boolean isPublic() {
        return Modifier.isPublic(method.getModifiers());
    }

    /** Return true if the method includes the {@code native} modifier. */
    public boolean isNative() {
        return Modifier.isNative(method.getModifiers());
    }

    /** Return true if the method includes the {@code static} modifier. */
    public boolean isStatic() {
        return Modifier.isStatic(method.getModifiers());
    }

    /** Return true if the method takes a variable number of arguments. */
    public boolean isVarArgs() {
        return method.isVarArgs();
    }

    /**
     * Invokes the underlying method on the supplied object with the supplied
     * parameters.
     */
    public Object invoke(Object obj, Object... args) throws ReflectionException {
        try {
            return method.invoke(obj, args);
        } catch (IllegalArgumentException e) {
            throw new ReflectionException("Illegal argument(s) supplied to method: " + getName(), e);
        } catch (IllegalAccessException e) {
            throw new ReflectionException("Illegal access to method: " + getName(), e);
        } catch (InvocationTargetException e) {
            throw new ReflectionException("Exception occurred in method: " + getName(), e);
        }
    }

    /**
     * Returns true if the method includes an annotation of the provided class
     * type.
     */
    public boolean isAnnotationPresent(Class<? extends java.lang.annotation.Annotation> annotationType) {
        return method.isAnnotationPresent(annotationType);
    }

    /**
     * Returns an array of {@link Annotation} objects reflecting all annotations
     * declared by this method, or an empty array if there are none. Does not
     * include inherited annotations. Does not include parameter annotations.
     */
    public Annotation[] getDeclaredAnnotations() {
        java.lang.annotation.Annotation[] annotations = method.getDeclaredAnnotations();
        Annotation[] result = new Annotation[annotations.length];
        for (int i = 0; i < annotations.length; i++) {
            result[i] = new Annotation(annotations[i]);
        }
        return result;
    }

    /**
     * Returns an {@link Annotation} object reflecting the annotation provided,
     * or null of this method doesn't have such an annotation. This is a
     * convenience function if the caller knows already which annotation type
     * he's looking for.
     */
    public Annotation getDeclaredAnnotation(Class<? extends java.lang.annotation.Annotation> annotationType) {
        java.lang.annotation.Annotation[] annotations = method.getDeclaredAnnotations();
        if (annotations == null) {
            return null;
        }
        for (java.lang.annotation.Annotation annotation : annotations) {
            if (annotation.annotationType().equals(annotationType)) {
                return new Annotation(annotation);
            }
        }
        return null;
    }

}