| 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 | public void afterPropertiesSet() throws Exception { |
| 65 | Assert.state(defaultValue != null || System.getProperty(keyName) != null, |
| 66 | "Either a default value must be specified or the value should already be set for System property: " |
| 67 | + keyName); |
| 68 | System.setProperty(keyName, System.getProperty(keyName, defaultValue)); |
| 69 | } |
| 70 | |
| 71 | } |