1 package org.apache.onami.persist;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import javax.inject.Singleton;
23 import javax.naming.InitialContext;
24 import javax.naming.NamingException;
25
26 /**
27 * Helper class which does a JNDI lookup and handles exceptions.
28 */
29 @Singleton
30 class JndiLookupHelper
31 {
32
33 /**
34 * Does the actual JNDI lookup.
35 *
36 * @param type type of the object to lookup
37 * @param jndiName name of the object to lookup
38 * @param <T> type of the object to lookup
39 * @return the object provided by the JNDI context.
40 */
41 @SuppressWarnings( "unchecked" )
42 <T> T doJndiLookup( Class<T> type, String jndiName )
43 {
44 try
45 {
46 final InitialContext ctx = new InitialContext();
47 final T result = (T) ctx.lookup( jndiName );
48
49 Preconditions.checkNotNull( result, "lookup for " + type.getSimpleName() + " with JNDI name '" + jndiName
50 + "' returned null" );
51
52 return result;
53 }
54 catch ( NamingException e )
55 {
56 throw new RuntimeException(
57 "lookup for " + type.getSimpleName() + " with JNDI name '" + jndiName + "' failed", e );
58 }
59 }
60
61 }