1 /*
2 * Copyright 2006-2007 the original author or authors.
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 package org.springframework.batch.support;
17
18 import org.springframework.beans.factory.InitializingBean;
19 import org.springframework.util.Assert;
20
21 /**
22 * Helper class that sets up a System property with a default value. A System
23 * property is created with the specified key name, and default value (i.e. if
24 * the property already exists it is not changed).
25 *
26 * @author Dave Syer
27 *
28 */
29 public class SystemPropertyInitializer implements InitializingBean {
30
31 /**
32 * Name of system property used by default.
33 */
34 public static final String ENVIRONMENT = "org.springframework.batch.support.SystemPropertyInitializer.ENVIRONMENT";
35
36 private String keyName = ENVIRONMENT;
37
38 private String defaultValue;
39
40 /**
41 * Set the key name for the System property that is created. Defaults to
42 * {@link #ENVIRONMENT}.
43 *
44 * @param keyName the key name to set
45 */
46 public void setKeyName(String keyName) {
47 this.keyName = keyName;
48 }
49
50 /**
51 * Mandatory property specifying the default value of the System property.
52 *
53 * @param defaultValue the default value to set
54 */
55 public void setDefaultValue(String defaultValue) {
56 this.defaultValue = defaultValue;
57 }
58
59 /**
60 * Sets the System property with the provided name and default value.
61 *
62 * @see InitializingBean#afterPropertiesSet()
63 */
64 @Override
65 public void afterPropertiesSet() throws Exception {
66 Assert.state(defaultValue != null || System.getProperty(keyName) != null,
67 "Either a default value must be specified or the value should already be set for System property: "
68 + keyName);
69 System.setProperty(keyName, System.getProperty(keyName, defaultValue));
70 }
71
72 }