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1   /*
2    * Copyright 2011 The Kuali Foundation.
3    *
4    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
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.kuali.ole.utility;
17  
18  import static org.apache.commons.lang.StringUtils.isBlank;
19  
20  import org.slf4j.Logger;
21  import org.slf4j.LoggerFactory;
22  
23  /**
24   * Logic for determining a base directory for Kuali applications by examining system properties and the environment the application is
25   * running in
26   */
27  public class ConfigUtil {
28      private static final Logger logger = LoggerFactory.getLogger(ConfigUtil.class);
29  
30      public static final String KUALI_HOME_SYSTEM_PROPERTY = "kuali.home";
31      public static final String KUALI_HOME_ENVIRONMENT_VAR = "KUALI_HOME";
32      public static final String KUALI_HOME_DEFAULT_VALUE = System.getProperty("user.home") + "/.kuali";
33  
34      /**
35       * Return the configured value for the <code>kuali.home</code> system property, the <code>KUALI_HOME</code> environment variable, or a
36       * default value for "kuali.home" based on "user.home".
37       * 
38       * When this method finishes the system property <code>kuali.home</code> is guaranteed to be set to the same value returned by this
39       * method.
40       */
41      public String getKualiHome() {
42          String kualiHome = getValue(KUALI_HOME_SYSTEM_PROPERTY, KUALI_HOME_ENVIRONMENT_VAR, KUALI_HOME_DEFAULT_VALUE);
43          String systemProperty = System.getProperty(KUALI_HOME_SYSTEM_PROPERTY);
44          if (!kualiHome.equals(systemProperty)) {
45              logger.info("Setting " + KUALI_HOME_SYSTEM_PROPERTY + "=" + kualiHome);
46              System.setProperty(KUALI_HOME_SYSTEM_PROPERTY, kualiHome);
47          }
48          return kualiHome;
49      }
50  
51      public String getGroupHome(String group) {
52          return getKualiHome() + "/" + group;
53      }
54  
55      public String getApplicationHome(String group, String application) {
56          return getGroupHome(group) + "/" + application;
57      }
58  
59      /**
60       * Locate a value by examining system properties and environment variables. If a system property is found, the system property always
61       * wins. Otherwise the logic defers to the environment variable before falling through to the default value.
62       * 
63       * @param systemProperty
64       * @param environmentVariable
65       * @param defaultValue
66       * @return
67       */
68      public String getValue(String systemProperty, String environmentVariable, String defaultValue) {
69          if (!isBlank(systemProperty) && !isBlank(System.getProperty(systemProperty))) {
70              return System.getProperty(systemProperty);
71          } else if (!isBlank(environmentVariable) && !isBlank(System.getenv(environmentVariable))) {
72              return System.getenv(environmentVariable);
73          } else {
74              return defaultValue;
75          }
76      }
77  }