cms/conient/Configuration.java

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

//---IMPORTS---
import java.util.Properties;
import java.io.*;

/**
 * Provides configuration details to Conient
 * This class is a Singleton class and
 *
 * @author  $Author: ajm4 $
 * @version $Id: Configuration.java,v 1.1 2001/01/30 02:13:34 ajm4 Exp $
 */
public class Configuration {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public static final String REVISION = "$Revision: 1.1 $";
    
//---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---

    public void readServerConfiguration(BufferedReader in, PrintWriter out) throws IOException {
        String response = null;
        out.println("Host.UDPUpdateTime");
        out.flush();
        response = in.readLine();
        
        if (!response.equals("ERROR")) {
            _properties.setProperty("Host.UDPUpdateTime", response);
        }
        out.println("Host.TCPUpdateTime");
        out.flush();
        response = in.readLine();
        
        if (!response.equals("ERROR")) {
            _properties.setProperty("Host.TCPUpdateTime", response);
        }
    }
    
//---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:	1.2
Committed:	Sat Feb 3 19:17:38 2001 UTC (23 years, 3 months ago) by ajm
Branch:	MAIN
Changes since 1.1:	+22 -7 lines
Log Message:	ConnectionHandler can now ask this class to obtain a configuaration over the control link.
#	Content
1	//---PACKAGE DECLARATION---
2	package uk.ac.ukc.iscream.conient;
3
4	//---IMPORTS---
5	import java.util.Properties;
6	import java.io.*;
7
8	/**
9	* Provides configuration details to Conient
10	* This class is a Singleton class and
11	*
12	* @author $Author: ajm4 $
13	* @version $Id: Configuration.java,v 1.1 2001/01/30 02:13:34 ajm4 Exp $
14	*/
15	public class Configuration {
16
17	//---FINAL ATTRIBUTES---
18
19	/**
20	* The current CVS revision of this class
21	*/
22	public static final String REVISION = "$Revision: 1.1 $";
23
24	//---STATIC METHODS---
25
26	/**
27	* Creates and initialises a the Configuration
28	* system for Conient. This calls the private
29	* constructor and ensures this class is a singleton.
30	*
31	* @param configFile the path to the file that this configuration should load
32	*/
33	public static void initialise(String configFile) {
34	_instance = new Configuration(configFile);
35	}
36
37	/**
38	* Returns the singleton instance of this
39	* class.
40	* This will throw a runtime exception if it
41	* is called at the wrong time!
42	*
43	* @return the singleton instance
44	*/
45	public static Configuration getInstance() {
46	if (_instance == null) {
47	throw new RuntimeException("Configuration class requested but HASN'T been initialised!");
48	}
49	return _instance;
50	}
51
52	//---CONSTRUCTORS---
53
54	/**
55	* The private constructor, ensures that this is a singleton.
56	* Simply reads in the local configuration from the file.
57	* Then sets the current properties to be this configuration.
58	* Later the system will obtain further configuration from the
59	* server.
60	*
61	* @param configFile the path to the file that this configuration should load
62	*/
63	private Configuration(String configFile) {
64	try {
65	_properties = readFileConfiguration(configFile);
66	} catch (FileNotFoundException e) {
67	// should show a box!
68	System.err.println("ERROR{configuration}: file not found - " + e.getMessage());
69	} catch (IOException e) {
70	// should show a box!
71	System.err.println("ERROR{configuration}: i/o error - " + e.getMessage());
72	}
73	}
74
75	//---PUBLIC METHODS---
76
77	public void readServerConfiguration(BufferedReader in, PrintWriter out) throws IOException {
78	String response = null;
79	out.println("Host.UDPUpdateTime");
80	out.flush();
81	response = in.readLine();
82
83	if (!response.equals("ERROR")) {
84	_properties.setProperty("Host.UDPUpdateTime", response);
85	}
86	out.println("Host.TCPUpdateTime");
87	out.flush();
88	response = in.readLine();
89
90	if (!response.equals("ERROR")) {
91	_properties.setProperty("Host.TCPUpdateTime", response);
92	}
93	}
94
95	//---PRIVATE METHODS---
96
97	/**
98	* Reads in the specified file and parses
99	* its properties.
100	*
101	* @param configFile the path of the file to be read
102	* @return the parsed properties
103	*/
104	private Properties readFileConfiguration(String configFile) throws FileNotFoundException, IOException {
105	File file = new File(configFile);
106	Properties configHolder = new Properties();
107	configHolder.load(new FileInputStream(file));
108	return configHolder;
109	}
110
111	//---ACCESSOR/MUTATOR METHODS---
112
113	/**
114	* A wrapper for java.util.Properties.getProperty
115	* When given a key it returns the value of that key
116	* ie, key = value
117	*
118	* @param key the key the value of which is wanted
119	*/
120	public String getProperty(String key) {
121	return _properties.getProperty(key);
122	}
123
124	//---ATTRIBUTES---
125
126	/**
127	* The current configuration in use
128	*/
129	private Properties _properties = null;
130
131	//---STATIC ATTRIBUTES---
132
133	/**
134	* The reference to the singleton instance of this class
135	*/
136	private static Configuration _instance = null;
137	}