PropertiesConfiguration


1   /*
2    * Copyright (c) 2002-2003 by OpenSymphony
3    * All rights reserved.
4    */
5   package com.opensymphony.webwork.config;
6   
7   import java.io.IOException  ;
8   import java.net.URL  ;
9   import java.util.Iterator  ;
10  import java.util.Properties  ;
11  
12  
13  /**
14   * A class to handle configuration via a properties file.
15   *
16   * @author Rickard �berg
17   * @author Jason Carreira
18   * @author Bill Lynch (docs)
19   */
20  public class PropertiesConfiguration extends Configuration {
21      //~ Instance fields ////////////////////////////////////////////////////////
22  
23      Properties   settings;
24  
25      //~ Constructors ///////////////////////////////////////////////////////////
26  
27      /**
28       * Creates a new properties config given the name of a properties file. The name is expected to NOT have
29       * the ".properties" file extension.  So when <tt>new PropertiesConfiguration("foo")</tt> is called
30       * this class will look in the classpath for the <tt>foo.properties</tt> file.
31       *
32       * @param name the name of the properties file, excluding the ".properties" extension.
33       */
34      public PropertiesConfiguration(String   name) {
35          settings = new Properties  ();
36  
37          URL   settingsUrl = Thread.currentThread().getContextClassLoader().getResource(name + ".properties");
38  
39          if (settingsUrl == null) {
40              throw new IllegalStateException  (name + ".properties missing");
41          }
42  
43          // Load settings
44          try {
45              settings.load(settingsUrl.openStream());
46          } catch (IOException   e) {
47              throw new RuntimeException  ("Could not load " + name + ".properties:" + e);
48          }
49      }
50  
51      //~ Methods ////////////////////////////////////////////////////////////////
52  
53      /**
54       * Sets a property in the properties file.
55       *
56       * @see #set(String, Object)
57       */
58      public void setImpl(String   aName, Object   aValue) {
59          settings.put(aName, aValue);
60      }
61  
62      /**
63       * Gets a property from the properties file.
64       *
65       * @see #get(String)
66       */
67      public Object   getImpl(String   aName) throws IllegalArgumentException   {
68          Object   setting = settings.get(aName);
69  
70          if (setting == null) {
71              throw new IllegalArgumentException  ("No such setting:" + aName);
72          }
73  
74          return setting;
75      }
76  
77      /**
78       * Tests to see if a property exists in the properties file.
79       *
80       * @see #isSet(String)
81       */
82      public boolean isSetImpl(String   aName) {
83          if (settings.get(aName) != null) {
84              return true;
85          } else {
86              return false;
87          }
88      }
89  
90      /**
91       * Lists all keys in the properties file.
92       *
93       * @see #list()
94       */
95      public Iterator   listImpl() {
96          return settings.keySet().iterator();
97      }
98  }
99
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Free Books Free Magazines
Popular Tags