1 /* ***************************************************************************
2 * Copyright (c) 2008 Brabenetz Harald, Austria.
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
18 package org.settings4j.connector;
19
20 /**
21 * Basic Implementation of {@link org.settings4j.Connector}s whiche are Property-related.
22 * <p>
23 * Only #getProperty(String, String) must be implemented.
24 * Example implementations are {@link PropertyFileConnector} or {@link SystemPropertyConnector}.
25 *
26 * @author Harald.Brabenetz
27 *
28 */
29 public abstract class AbstractPropertyConnector extends AbstractConnector {
30
31 /** {@inheritDoc} */
32 public byte[] getContent(final String key) {
33 final String path = getString(key);
34 if (path != null && getContentResolver() != null) {
35 return getContentResolver().getContent(path);
36 }
37 // else
38 return null;
39
40 }
41
42 /** {@inheritDoc} */
43 public Object getObject(final String key) {
44 final String path = getString(key);
45 if (path != null && getObjectResolver() != null) {
46 return getObjectResolver().getObject(path, getContentResolver());
47 }
48 // else
49 return null;
50
51 }
52
53 /** {@inheritDoc} */
54 public String getString(final String key) {
55 return getProperty(key, null);
56 }
57
58 /**
59 * Very similar to <code>System.getProperty</code> except that the {@link SecurityException} is hidden.
60 *
61 * @param key The key to search for.
62 * @param defaultValue The default value to return.
63 * @return the string value of the system property, or the default value if there is no property with that key.
64 */
65 protected abstract String getProperty(String key, String defaultValue);
66 }