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, 3 months ago) by ajm
Branch:	MAIN
Log Message:	initial checkin of the configuration system
#	User	Rev	Content
1	ajm	1.1	//---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			}