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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
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package com.sun.beans.decoder;

import com.sun.beans.finder.MethodFinder;

import java.lang.reflect.Method;

import sun.reflect.misc.MethodUtil;

This class is intended to handle <method> element. It describes invocation of the method. The name attribute denotes the name of the method to invoke. If the class attribute is specified this element invokes static method of specified class. The inner elements specifies the arguments of the method. For example:
<method name="valueOf" class="java.lang.Long">
    <string>10</string>
</method>
 is equivalent to Long.valueOf("10") in Java code. 
The following attributes are supported:

name
the method name
class
the type of object for instantiation
id
the identifier of the variable that is intended to store the result

Author:
Sergey A. Malenkov
Since:
1.7/**
 * This class is intended to handle &lt;method&gt; element.
 * It describes invocation of the method.
 * The {@code name} attribute denotes
 * the name of the method to invoke.
 * If the {@code class} attribute is specified
 * this element invokes static method of specified class.
 * The inner elements specifies the arguments of the method.
 * For example:<pre>
 * &lt;method name="valueOf" class="java.lang.Long"&gt;
 *     &lt;string&gt;10&lt;/string&gt;
 * &lt;/method&gt;</pre>
 * is equivalent to {@code Long.valueOf("10")} in Java code.
 * <p>The following attributes are supported:
 * <dl>
 * <dt>name
 * <dd>the method name
 * <dt>class
 * <dd>the type of object for instantiation
 * <dt>id
 * <dd>the identifier of the variable that is intended to store the result
 * </dl>
 *
 * @since 1.7
 *
 * @author Sergey A. Malenkov
 */
final class MethodElementHandler extends NewElementHandler {
    private String name;

    
Parses attributes of the element.
The following attributes are supported:

name
the method name
class
the type of object for instantiation
id
the identifier of the variable that is intended to store the result

Params:
name –   the attribute name
value –  the attribute value/**
     * Parses attributes of the element.
     * The following attributes are supported:
     * <dl>
     * <dt>name
     * <dd>the method name
     * <dt>class
     * <dd>the type of object for instantiation
     * <dt>id
     * <dd>the identifier of the variable that is intended to store the result
     * </dl>
     *
     * @param name   the attribute name
     * @param value  the attribute value
     */
    @Override
    public void addAttribute(String name, String value) {
        if (name.equals("name")) { // NON-NLS: the attribute name
            this.name = value;
        } else {
            super.addAttribute(name, value);
        }
    }

    
Returns the result of method execution.
Params:
type –  the base class
args –  the array of arguments
Throws:
Exception – if calculation is failed
Returns:
the value of this element/**
     * Returns the result of method execution.
     *
     * @param type  the base class
     * @param args  the array of arguments
     * @return the value of this element
     * @throws Exception if calculation is failed
     */
    @Override
    protected ValueObject getValueObject(Class<?> type, Object[] args) throws Exception {
        Object bean = getContextBean();
        Class<?>[] types = getArgumentTypes(args);
        Method method = (type != null)
                ? MethodFinder.findStaticMethod(type, this.name, types)
                : MethodFinder.findMethod(bean.getClass(), this.name, types);

        if (method.isVarArgs()) {
            args = getArguments(args, method.getParameterTypes());
        }
        Object value = MethodUtil.invoke(method, bean, args);
        return method.getReturnType().equals(void.class)
                ? ValueObjectImpl.VOID
                : ValueObjectImpl.create(value);
    }
}