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root/i-scream/experimental/agents/AgentStation.java
Revision: 1.3
Committed: Sun May 6 19:01:48 2001 UTC (22 years, 10 months ago) by ajm
Branch: MAIN
CVS Tags: HEAD
Changes since 1.2: +4 -3 lines
Error occurred while calculating annotation data.
Log Message:
Now has some VERY crude byte code passing mechanisms in place.

Currently it does it a very silly and non standard way, this will change.  But hey, it works ;p

File Contents

# Content
1 //---PACKAGE DECLARATION---
2
3 //---IMPORTS---
4 import java.net.Socket;
5 import java.io.IOException;
6 import java.util.ArrayList;
7
8 /**
9 * An implementation of an agent station
10 *
11 * @author $Author: ajm4 $
12 * @version $Id: AgentStation.java,v 1.2 2001/05/04 02:04:35 ajm4 Exp $
13 */
14 class AgentStation extends Station {
15
16 //---FINAL / FINAL STATIC ATTRIBUTES---
17
18 /**
19 * The current CVS revision of this class
20 */
21 public static final String REVISION = "$Revision: 1.2 $";
22
23 public static final int DIRECT_LISTEN_PORT = 32497;
24
25 public static final int PEER_LISTEN_PORT = 32498;
26
27 //---STATIC METHODS---
28
29 /**
30 * Returns a reference to the singleton agent station in use
31 *
32 * @throws RuntimeException if not yet initialised
33 */
34 public static AgentStation getInstance() throws RuntimeException {
35 if (_instance == null) {
36 throw new RuntimeException("Cannot obtain instance to uninitialised AgentStation!");
37 }
38 return _instance;
39 }
40
41 /**
42 * Constructs and returns the singleton AgentStation class
43 *
44 * @throws RuntimeException if already initialised
45 */
46 public static AgentStation initialise(String name, String descriptiveName, String initialPeerHostname, int initialPeerPort) {
47 if (_instance != null) {
48 throw new RuntimeException("Already initialised!");
49 }
50 _instance = new AgentStation(name, descriptiveName, initialPeerHostname, initialPeerPort);
51 return _instance;
52 }
53
54 //---CONSTRUCTORS---
55
56 /**
57 * Starts up the agent station.
58 * This is a private method to ensure singleton pattern.
59 */
60 private AgentStation(String name, String descriptiveName, String initialPeerHostname, int initialPeerPort) {
61 _name = name;
62 _descriptiveName = descriptiveName;
63
64 DirectAgentHandlerFactory directAgentHandlerFactory = new DirectAgentHandlerFactory();
65 PeerHandlerFactory peerHandlerFactory = new PeerHandlerFactory();
66
67 Listener directAgentListener = new Listener(DIRECT_LISTEN_PORT, directAgentHandlerFactory);
68 Listener peerListener = new Listener(PEER_LISTEN_PORT, peerHandlerFactory);
69
70 directAgentListener.start();
71 peerListener.start();
72
73 // TESTING ONLY - Have one peer connection
74 if (initialPeerHostname != null) {
75 try {
76 _logger.write(toString(), Logger.DEBUG, "Establishing peer connection with - " + initialPeerHostname + ":" + initialPeerPort);
77 Socket socket = new Socket(initialPeerHostname, initialPeerPort);
78
79 PeerHandler peerHandler = new PeerHandler(socket);
80 addPeer(peerHandler);
81 peerHandler.start();
82 } catch (IOException e) {
83 _logger.write(toString(), Logger.ERROR, "I/O ERROR - " + e);
84 }
85 }
86 _logger.write(toString(), Logger.SYSINIT, "created");
87 }
88
89 //---PUBLIC METHODS---
90
91 //*** STATION SERVICES TO AGENTS ***
92
93 public ArrayList getAllAgents() {
94 return _agentList;
95 }
96
97 public ArrayList getAllPeers() {
98 return _peerList;
99 }
100
101 public String getName() {
102 return _name + " - " + _descriptiveName;
103 }
104
105 public void sendAgent(Agent agent, PeerHandler peerHandler) {
106 // NOTE - no support for restarting agent on a failed send.
107 agent.shutdown();
108 ((PeerHandler) _peerList.get(_peerList.indexOf(peerHandler))).sendAgent(agent);
109 }
110
111 //*** OTHER PUBLIC METHODS ***
112
113 public void addAgent(Agent agent) {
114 _logger.write(toString(), Logger.DEBUG, "registered agent");
115 _agentList.add(agent);
116 }
117
118 public void removeAgent(Agent agent) {
119 _agentList.remove(_agentList.indexOf(agent));
120 _logger.write(toString(), Logger.DEBUG, "deregistered agent");
121 }
122
123 public void addPeer(PeerHandler peerHandler) {
124 _logger.write(toString(), Logger.DEBUG, "registered peer");
125 _peerList.add(peerHandler);
126 }
127
128 public void removePeer(PeerHandler peerHandler) {
129 _peerList.remove(peerHandler);
130 _logger.write(toString(), Logger.DEBUG, "deregistered peer");
131 }
132
133 /**
134 * Overrides the {@link java.lang.Object#toString() Object.toString()}
135 * method to provide clean logging (every class should have this).
136 *
137 * This uses the uk.ac.ukc.iscream.util.FormatName class
138 * to format the toString()
139 *
140 * @return the name of this class and its CVS revision
141 */
142 public String toString() {
143 return FormatName.getName(
144 _name,
145 getClass().getName(),
146 REVISION);
147 }
148
149 //---PRIVATE/PROTECTED METHODS---
150
151 //---ACCESSOR/MUTATOR METHODS---
152
153 //---ATTRIBUTES---
154
155 /**
156 * This is the friendly identifier of the
157 * component this class is running in.
158 * eg, a Filter may be called "filter1",
159 * If this class does not have an owning
160 * component, a name from the configuration
161 * can be placed here. This name could also
162 * be changed to null for utility classes.
163 */
164 private String _name;
165
166 /**
167 * This holds a reference to the
168 * system logger that is being used.
169 */
170 private Logger _logger = Logger.getInstance();
171
172 private String _descriptiveName;
173
174 private ArrayList _agentList = new ArrayList();
175
176 private ArrayList _peerList = new ArrayList();
177
178 //---STATIC ATTRIBUTES---
179
180 /**
181 * Holds the reference to the singleton instance of his class
182 */
183 private static AgentStation _instance;
184
185
186 }