cms/conient/Configuration.java

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

//---IMPORTS---
import javax.swing.JOptionPane;
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 1.3 2001/02/04 23:45:10 ajm4 Exp $
 */
public class Configuration {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public static final String REVISION = "$Revision: 1.3 $";
    
//---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) {
            JOptionPane.showMessageDialog(null, "Configuration file not found - " + configFile, "Configuration Error", JOptionPane.ERROR_MESSAGE);
            System.exit(1);
        } catch (IOException e) {
            JOptionPane.showMessageDialog(null, "Unable to read configuration file - " + e.getMessage(), "Configuration Error", JOptionPane.ERROR_MESSAGE);
            System.exit(1);
        }
    }

//---PUBLIC METHODS---

    /**
     * This routine asks the server for all configuration
     * options that are needed to be obtained from the
     * server.  It takes hooks to the I/O streams for the
     * control link socket in order that it can request
     * the attributes.  It is assumed that the connection 
     * has been negotiated to a stage that the server is
     * ready to server attributes.  Once this method returns
     * the calling class should tell the server that configuration
     * has terminated.
     *
     * @param in the input stream of the control link
     * @param out the output stream of the control link
     * @throws IOException if there is an error communicating
     */
    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);
        }
    }
    
    /**
     * Tells the configuration class that it should
     * perform user re-configuration through displaying
     * a gui.  This passes control to a dialog to 
     * handle re-configuration.  Basically this is
     * the nicer alternative to hacking the config
     * file.
     * The ConientConfiguration class is responsible
     * for handling the re-configuration.
     */
    public void GUIReconfiguration() {
        //ConientConfiguration conf = new ConientConfiguration();
    }
//---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:	1.4
Committed:	Fri Feb 16 16:24:08 2001 UTC (24 years, 9 months ago) by ajm
Branch:	MAIN
Changes since 1.3:	+30 -2 lines
Log Message:	An extra bit of javadoc, and now has the start of support for GUI config
#	Content
1	//---PACKAGE DECLARATION---
2	package uk.ac.ukc.iscream.conient;
3
4	//---IMPORTS---
5	import javax.swing.JOptionPane;
6	import java.util.Properties;
7	import java.io.*;
8
9	/**
10	* Provides configuration details to Conient
11	* This class is a Singleton class and
12	*
13	* @author $Author: ajm4 $
14	* @version $Id: Configuration.java,v 1.3 2001/02/04 23:45:10 ajm4 Exp $
15	*/
16	public class Configuration {
17
18	//---FINAL ATTRIBUTES---
19
20	/**
21	* The current CVS revision of this class
22	*/
23	public static final String REVISION = "$Revision: 1.3 $";
24
25	//---STATIC METHODS---
26
27	/**
28	* Creates and initialises a the Configuration
29	* system for Conient. This calls the private
30	* constructor and ensures this class is a singleton.
31	*
32	* @param configFile the path to the file that this configuration should load
33	*/
34	public static void initialise(String configFile) {
35	_instance = new Configuration(configFile);
36	}
37
38	/**
39	* Returns the singleton instance of this
40	* class.
41	* This will throw a runtime exception if it
42	* is called at the wrong time!
43	*
44	* @return the singleton instance
45	*/
46	public static Configuration getInstance() {
47	if (_instance == null) {
48	throw new RuntimeException("Configuration class requested but HASN'T been initialised!");
49	}
50	return _instance;
51	}
52
53	//---CONSTRUCTORS---
54
55	/**
56	* The private constructor, ensures that this is a singleton.
57	* Simply reads in the local configuration from the file.
58	* Then sets the current properties to be this configuration.
59	* Later the system will obtain further configuration from the
60	* server.
61	*
62	* @param configFile the path to the file that this configuration should load
63	*/
64	private Configuration(String configFile) {
65	try {
66	_properties = readFileConfiguration(configFile);
67	} catch (FileNotFoundException e) {
68	JOptionPane.showMessageDialog(null, "Configuration file not found - " + configFile, "Configuration Error", JOptionPane.ERROR_MESSAGE);
69	System.exit(1);
70	} catch (IOException e) {
71	JOptionPane.showMessageDialog(null, "Unable to read configuration file - " + e.getMessage(), "Configuration Error", JOptionPane.ERROR_MESSAGE);
72	System.exit(1);
73	}
74	}
75
76	//---PUBLIC METHODS---
77
78	/**
79	* This routine asks the server for all configuration
80	* options that are needed to be obtained from the
81	* server. It takes hooks to the I/O streams for the
82	* control link socket in order that it can request
83	* the attributes. It is assumed that the connection
84	* has been negotiated to a stage that the server is
85	* ready to server attributes. Once this method returns
86	* the calling class should tell the server that configuration
87	* has terminated.
88	*
89	* @param in the input stream of the control link
90	* @param out the output stream of the control link
91	* @throws IOException if there is an error communicating
92	*/
93	public void readServerConfiguration(BufferedReader in, PrintWriter out) throws IOException {
94	String response = null;
95	out.println("Host.UDPUpdateTime");
96	out.flush();
97	response = in.readLine();
98
99	if (!response.equals("ERROR")) {
100	_properties.setProperty("Host.UDPUpdateTime", response);
101	}
102	out.println("Host.TCPUpdateTime");
103	out.flush();
104	response = in.readLine();
105
106	if (!response.equals("ERROR")) {
107	_properties.setProperty("Host.TCPUpdateTime", response);
108	}
109	}
110
111	/**
112	* Tells the configuration class that it should
113	* perform user re-configuration through displaying
114	* a gui. This passes control to a dialog to
115	* handle re-configuration. Basically this is
116	* the nicer alternative to hacking the config
117	* file.
118	* The ConientConfiguration class is responsible
119	* for handling the re-configuration.
120	*/
121	public void GUIReconfiguration() {
122	//ConientConfiguration conf = new ConientConfiguration();
123	}
124	//---PRIVATE METHODS---
125
126	/**
127	* Reads in the specified file and parses
128	* its properties.
129	*
130	* @param configFile the path of the file to be read
131	* @return the parsed properties
132	*/
133	private Properties readFileConfiguration(String configFile) throws FileNotFoundException, IOException {
134	File file = new File(configFile);
135	Properties configHolder = new Properties();
136	configHolder.load(new FileInputStream(file));
137	return configHolder;
138	}
139
140	//---ACCESSOR/MUTATOR METHODS---
141
142	/**
143	* A wrapper for java.util.Properties.getProperty
144	* When given a key it returns the value of that key
145	* ie, key = value
146	*
147	* @param key the key the value of which is wanted
148	*/
149	public String getProperty(String key) {
150	return _properties.getProperty(key);
151	}
152
153	//---ATTRIBUTES---
154
155	/**
156	* The current configuration in use
157	*/
158	private Properties _properties = null;
159
160	//---STATIC ATTRIBUTES---
161
162	/**
163	* The reference to the singleton instance of this class
164	*/
165	private static Configuration _instance = null;
166	}