Java example source code file (ValueGetter.java)

This example Java source code file (ValueGetter.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

holder, object, plain, valuegetter, xml

The ValueGetter.java Java example source code

/*
 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * 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.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.xml.internal.ws.server.sei;

import com.sun.xml.internal.ws.model.ParameterImpl;
import com.sun.xml.internal.ws.api.model.Parameter;

import javax.jws.WebParam.Mode;
import javax.xml.ws.Holder;

/**
 * Gets a value from an object that represents a parameter passed
 * as a method argument.
 *
 * <p>
 * This abstraction hides the handling of {@link Holder}.
 *
 * <p>
 * {@link ValueGetter} is a stateless behavior encapsulation.
 *
 * @author Kohsuke Kawaguchi
 */
public enum ValueGetter {
    /**
     * {@link ValueGetter} that works for {@link Mode#IN}  parameter.
     *
     * <p>
     * Since it's the IN mode, the parameter is not a {@link Holder},
     * therefore the parameter itself is a value.
     */
    PLAIN() {
        public Object get(Object parameter) {
            return parameter;
        }
    },
    /**
     * Creates {@link ValueGetter} that works for {@link Holder},
     * which is  {@link Mode#INOUT} or  {@link Mode#OUT}.
     *
     * <p>
     * In those {@link Mode}s, the parameter is a {@link Holder},
     * so the value to be sent is obtained by getting the value of the holder.
     */
    HOLDER() {
        public Object get(Object parameter) {
            if(parameter==null)
                // the user is allowed to pass in null where a Holder is expected.
                return null;
            return ((Holder)parameter).value;
        }
    };

    /**
     * Gets the value to be sent, from a parameter given as a method argument.
     */
    public abstract Object get(Object parameter);

    /**
     * Returns a {@link ValueGetter} suitable for the given {@link Parameter}.
     */
    public static ValueGetter get(ParameterImpl p) {
        // return value is always PLAIN
        if(p.getMode() == Mode.IN || p.getIndex() == -1) {
            return PLAIN;
        } else {
            return HOLDER;
        }
    }
}