abstractjaxbprovider.java

来自「resetful样式的ws样例,一种面向资源的webservices服务」· Java 代码 · 共 77 行

/*
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * 
 * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
 * 
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License. You can obtain
 * a copy of the License at https://jersey.dev.java.net/CDDL+GPL.html
 * or jersey/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 * 
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at jersey/legal/LICENSE.txt.
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 * as provided by Sun in the GPL Version 2 section of the License file that
 * accompanied this code.  If applicable, add the following below the License
 * Header, with the fields enclosed by brackets [] replaced by your own
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 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

package com.sun.jersey.impl.provider.entity;

import java.util.Map;
import java.util.WeakHashMap;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.ext.ContextResolver;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;

/**
 *
 * @author [e-mail]
 */
public abstract class AbstractJAXBProvider<T> extends AbstractMessageReaderWriterProvider<T> {    
    private static Map<Class, JAXBContext> jaxbContexts = 
            new WeakHashMap<Class, JAXBContext>();

    @Context private ContextResolver<JAXBContext> cr;
    
    protected final JAXBContext getJAXBContext(Class type) throws JAXBException {
        if (cr != null) {
            JAXBContext c = cr.getContext(type);
            if (c != null) return c;
        }
        
        synchronized (jaxbContexts) {
            JAXBContext context = jaxbContexts.get(type);
            if (context == null) {
                context = JAXBContext.newInstance(type);
                jaxbContexts.put(type, context);
            }
            return context;
        }
    }
    
    public static final String getCharsetAsString(MediaType m) {
        return (m == null) ? null : m.getParameters().get("charset");
    }    
}