01: /*
02: * Licensed to the Apache Software Foundation (ASF) under one
03: * or more contributor license agreements. See the NOTICE file
04: * distributed with this work for additional information
05: * regarding copyright ownership. The ASF licenses this file
06: * to you under the Apache License, Version 2.0 (the
07: * "License"); you may not use this file except in compliance
08: * with the License. You may obtain a copy of the License at
09: *
10: * http://www.apache.org/licenses/LICENSE-2.0
11: *
12: * Unless required by applicable law or agreed to in writing,
13: * software distributed under the License is distributed on an
14: * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15: * KIND, either express or implied. See the License for the
16: * specific language governing permissions and limitations
17: * under the License.
18: */
19: package org.apache.openjpa.lib.log;
20:
21: import java.util.Map;
22:
23: import org.apache.openjpa.lib.util.concurrent.ConcurrentHashMap;
24:
25: /**
26: * Base type that aids in adapting an external log framework to the
27: * {@link LogFactory}.
28: *
29: * @author Abe White
30: */
31: public abstract class LogFactoryAdapter implements LogFactory {
32:
33: // cache category to log adapters
34: private Map _logs = new ConcurrentHashMap();
35:
36: public Log getLog(String channel) {
37: // no locking; OK if same adapter created multiple times
38: Log log = (Log) _logs.get(channel);
39: if (log == null) {
40: log = newLogAdapter(channel);
41: _logs.put(channel, log);
42: }
43: return log;
44: }
45:
46: /**
47: * Return a log adapter for the given channel. This method may be called
48: * multiple times for the same channel in concurrent situations.
49: */
50: protected abstract Log newLogAdapter(String channel);
51: }
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