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      1 /**
      2  * Copyright (C) 2006 Google Inc.
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  * http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.google.inject.jndi;
     18 
     19 import com.google.inject.Inject;
     20 import com.google.inject.Provider;
     21 
     22 import javax.naming.Context;
     23 import javax.naming.NamingException;
     24 
     25 /**
     26  * Integrates Guice with JNDI. Requires a binding to
     27  * {@link javax.naming.Context}.
     28  *
     29  * @author crazybob (at) google.com (Bob Lee)
     30  */
     31 public class JndiIntegration {
     32 
     33   private JndiIntegration() {}
     34 
     35   /**
     36    * Creates a provider which looks up objects in JNDI using the given name.
     37    * Example usage:
     38    *
     39    * <pre>
     40    * bind(DataSource.class).toProvider(fromJndi(DataSource.class, "java:..."));
     41    * </pre>
     42    */
     43   public static <T> Provider<T> fromJndi(Class<T> type, String name) {
     44     return new JndiProvider<T>(type, name);
     45   }
     46 
     47   static class JndiProvider<T> implements Provider<T> {
     48 
     49     @Inject Context context;
     50     final Class<T> type;
     51     final String name;
     52 
     53     public JndiProvider(Class<T> type, String name) {
     54       this.type = type;
     55       this.name = name;
     56     }
     57 
     58     public T get() {
     59       try {
     60         return type.cast(context.lookup(name));
     61       }
     62       catch (NamingException e) {
     63         throw new RuntimeException(e);
     64       }
     65     }
     66   }
     67 }
     68