cms/conient/Configuration.java

//---PACKAGE DECLARATION---
package uk.ac.ukc.iscream.conient;

//---IMPORTS---
import java.util.Properties;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.FileNotFoundException;

/**
 * Provides configuration details to Conient
 * This class is a Singleton class and
 *
 * @author  $Author: tdb1 $
 * @version $Id: TemplateClass.java,v 1.10 2001/01/18 23:14:39 tdb1 Exp $
 */
public class Configuration {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public static final String REVISION = "$Revision: 1.10 $";
    
//---STATIC METHODS---

    /**
     * Creates and initialises a the Configuration
     * system for Conient.  This calls the private
     * constructor and ensures this class is a singleton.
     *
     * @param configFile the path to the file that this configuration should load
     */
    public static void initialise(String configFile) {
        _instance = new Configuration(configFile);
    }

    /**
     * Returns the singleton instance of this
     * class.
     * This will throw a runtime exception if it 
     * is called at the wrong time!
     *
     * @return the singleton instance
     */
    public static Configuration getInstance() {
        if (_instance == null) {
            throw new RuntimeException("Configuration class requested but HASN'T been initialised!");
        }
        return _instance;
    }

//---CONSTRUCTORS---

    /**
     * The private constructor, ensures that this is a singleton.
     * Simply reads in the local configuration from the file.
     * Then sets the current properties to be this configuration.
     * Later the system will obtain further configuration from the
     * server.
     *
     * @param configFile the path to the file that this configuration should load
     */
    private Configuration(String configFile) {
        try {
            _properties = readFileConfiguration(configFile);
        } catch (FileNotFoundException e) {
            // should show a box!
            System.err.println("ERROR{configuration}: file not found - " + e.getMessage());
        } catch (IOException e) {
            // should show a box!
            System.err.println("ERROR{configuration}: i/o error - " + e.getMessage());
        }
    }

//---PUBLIC METHODS---

//---PRIVATE METHODS---

    /**
     * Reads in the specified file and parses
     * its properties.
     *
     * @param configFile the path of the file to be read
     * @return the parsed properties
     */
    private Properties readFileConfiguration(String configFile) throws FileNotFoundException, IOException {
        File file = new File(configFile);
        Properties configHolder = new Properties();
        configHolder.load(new FileInputStream(file));
        return configHolder;
    }

//---ACCESSOR/MUTATOR METHODS---

    /**
     * A wrapper for java.util.Properties.getProperty
     * When given a key it returns the value of that key
     * ie, key = value
     *
     * @param key the key the value of which is wanted
     */
    public String getProperty(String key) {
        return _properties.getProperty(key); 
    }

//---ATTRIBUTES---

    /**
     * The current configuration in use
     */
    private Properties _properties = null;

//---STATIC ATTRIBUTES---

    /**
     * The reference to the singleton instance of this class
     */
    private static Configuration _instance = null;
}
Revision:	1.1
Committed:	Tue Jan 30 02:13:34 2001 UTC (23 years, 4 months ago) by ajm
Branch:	MAIN
Log Message:	initial checkin of the configuration system
#	Content
1	//---PACKAGE DECLARATION---
2	package uk.ac.ukc.iscream.conient;
3
4	//---IMPORTS---
5	import java.util.Properties;
6	import java.io.File;
7	import java.io.FileInputStream;
8	import java.io.IOException;
9	import java.io.FileNotFoundException;
10
11	/**
12	* Provides configuration details to Conient
13	* This class is a Singleton class and
14	*
15	* @author $Author: tdb1 $
16	* @version $Id: TemplateClass.java,v 1.10 2001/01/18 23:14:39 tdb1 Exp $
17	*/
18	public class Configuration {
19
20	//---FINAL ATTRIBUTES---
21
22	/**
23	* The current CVS revision of this class
24	*/
25	public static final String REVISION = "$Revision: 1.10 $";
26
27	//---STATIC METHODS---
28
29	/**
30	* Creates and initialises a the Configuration
31	* system for Conient. This calls the private
32	* constructor and ensures this class is a singleton.
33	*
34	* @param configFile the path to the file that this configuration should load
35	*/
36	public static void initialise(String configFile) {
37	_instance = new Configuration(configFile);
38	}
39
40	/**
41	* Returns the singleton instance of this
42	* class.
43	* This will throw a runtime exception if it
44	* is called at the wrong time!
45	*
46	* @return the singleton instance
47	*/
48	public static Configuration getInstance() {
49	if (_instance == null) {
50	throw new RuntimeException("Configuration class requested but HASN'T been initialised!");
51	}
52	return _instance;
53	}
54
55	//---CONSTRUCTORS---
56
57	/**
58	* The private constructor, ensures that this is a singleton.
59	* Simply reads in the local configuration from the file.
60	* Then sets the current properties to be this configuration.
61	* Later the system will obtain further configuration from the
62	* server.
63	*
64	* @param configFile the path to the file that this configuration should load
65	*/
66	private Configuration(String configFile) {
67	try {
68	_properties = readFileConfiguration(configFile);
69	} catch (FileNotFoundException e) {
70	// should show a box!
71	System.err.println("ERROR{configuration}: file not found - " + e.getMessage());
72	} catch (IOException e) {
73	// should show a box!
74	System.err.println("ERROR{configuration}: i/o error - " + e.getMessage());
75	}
76	}
77
78	//---PUBLIC METHODS---
79
80	//---PRIVATE METHODS---
81
82	/**
83	* Reads in the specified file and parses
84	* its properties.
85	*
86	* @param configFile the path of the file to be read
87	* @return the parsed properties
88	*/
89	private Properties readFileConfiguration(String configFile) throws FileNotFoundException, IOException {
90	File file = new File(configFile);
91	Properties configHolder = new Properties();
92	configHolder.load(new FileInputStream(file));
93	return configHolder;
94	}
95
96	//---ACCESSOR/MUTATOR METHODS---
97
98	/**
99	* A wrapper for java.util.Properties.getProperty
100	* When given a key it returns the value of that key
101	* ie, key = value
102	*
103	* @param key the key the value of which is wanted
104	*/
105	public String getProperty(String key) {
106	return _properties.getProperty(key);
107	}
108
109	//---ATTRIBUTES---
110
111	/**
112	* The current configuration in use
113	*/
114	private Properties _properties = null;
115
116	//---STATIC ATTRIBUTES---
117
118	/**
119	* The reference to the singleton instance of this class
120	*/
121	private static Configuration _instance = null;
122	}