widgetsresource.java

来自「resetful样式的ws样例,一种面向资源的webservices服务」· Java 代码 · 共 89 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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 * Version 2] license."  If you don't indicate a single choice of license, a
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 * 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
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 */

/*
 * WidgetsResource.java
 *
 * Created on April 6, 2007, 5:08 PM
 *
 */

package com.sun.jersey.samples.persistence.resources;

import com.sun.jersey.samples.persistence.Widget;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.PersistenceUnit;
import javax.persistence.Query;
import javax.ws.rs.GET;
import javax.ws.rs.ProduceMime;
import javax.ws.rs.Path;

@Path("/widgets")
public class WidgetsResource {
    
    @PersistenceUnit(unitName="WidgetPU")
    EntityManagerFactory emf;
    
    /** Creates a new instance of WidgetsResource */
    public WidgetsResource() {
    }
    
    @ProduceMime("text/plain")
    @GET
    public String getListOfWidgets() {
        StringBuilder b = new StringBuilder();
        EntityManager em = null;
        try {
            em = emf.createEntityManager();
            Query q = em.createQuery("SELECT w FROM Widget w");
            List<Widget> results = (List<Widget>)q.getResultList();
            for (Widget w: results) {
                b.append(w.getName()+": "+w.getDescription()+"\n");
            }
        } catch (Exception ex) {
            b.append(ex.toString());
        } finally {
            if (em != null)
                em.close();
        }
        return b.toString();
    }
}