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1   /**
2   The contents of this file are subject to the Mozilla Public License Version 1.1 
3   (the "License"); you may not use this file except in compliance with the License. 
4   You may obtain a copy of the License at http://www.mozilla.org/MPL/ 
5   Software distributed under the License is distributed on an "AS IS" basis, 
6   WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the 
7   specific language governing rights and limitations under the License. 
8   
9   The Original Code is "NormativeDatabase.java".  Description: 
10  "Point of access to a copy of the HL7 normative database" 
11  
12  The Initial Developer of the Original Code is University Health Network. Copyright (C) 
13  2001.  All Rights Reserved. 
14  
15  Contributor(s): ______________________________________. 
16  
17  Alternatively, the contents of this file may be used under the terms of the 
18  GNU General Public License (the  �GPL�), in which case the provisions of the GPL are 
19  applicable instead of those above.  If you wish to allow use of your version of this 
20  file only under the terms of the GPL and not to allow others to use your version 
21  of this file under the MPL, indicate your decision by deleting  the provisions above 
22  and replace  them with the notice and other provisions required by the GPL License.  
23  If you do not delete the provisions above, a recipient may use your version of 
24  this file under either the MPL or the GPL. 
25  
26   */
27  
28  package ca.uhn.hl7v2.database;
29  
30  import java.sql.Connection;
31  import java.sql.DriverManager;
32  import java.sql.ResultSet;
33  import java.sql.SQLException;
34  import java.sql.Statement;
35  
36  import org.slf4j.Logger;
37  import org.slf4j.LoggerFactory;
38  
39  /**
40   * <p>
41   * Point of access to a copy of the HL7 normative database. A typical way of obtaining and using a
42   * database connection would be ...
43   * </p>
44   * <p>
45   * <code>Connection c = NormativeDatabase.getInstance().getConnection();<br>
46   * // ... use the database ... <br>
47   * NormativeDatabase.returnConnection(c);</code>
48   * </p>
49   * <p>
50   * Since the database may be installed differently on different systems, certain system properties
51   * must be set with the required connection information, as follows:
52   * </p>
53   * <p>
54   * <code>ca.on.uhn.hl7.database.user</code> - the user ID needed to connect (if required)<br>
55   * <code>ca.on.uhn.hl7.database.passsword</code> - the password associated with the above user (if
56   * required)
57   * </p>
58   * <p>
59   * The required JDBC driver must also be loaded (this can be done by ensuring that the required
60   * driver appears in the classpath and appending the class name to the "jdbc.drivers" system
61   * property.
62   * 
63   * @author Bryan Tripp (bryan_tripp@sourceforge.net)
64   */
65  public class NormativeDatabase
66  {
67  	/** User system property constant */
68      public static final String PROP_DATABASE_USER = "ca.on.uhn.hl7.database.user";
69  	/** User system property constant */
70      public static final String PROP_DATABASE_URL = "ca.on.uhn.hl7.database.url";
71  	/** User system property constant */
72      public static final String PROP_DATABASE_PASSWORD = "ca.on.uhn.hl7.database.password";
73  
74  	private static final Logger log = LoggerFactory.getLogger(NormativeDatabase.class);
75  
76      private static final NormativeDatabase INSTANCE = new NormativeDatabase();
77  
78      private String dbUrl;
79      private String dbUser;
80      private String dbPassword;
81  
82      private Connection connection;
83  	private SQLException checkedOut;
84  
85  
86      /**
87       * Private constructor
88       */
89      private NormativeDatabase() {
90      	// nothing
91      }
92  
93  
94      /**
95       * Returns the singleton instance of NormativeDatabase.
96       */
97      public static NormativeDatabase getInstance() throws SQLException {
98      	return INSTANCE;
99      }
100 
101 
102     /**
103      * Provides a Connection to the normative database. A new connection may be created if none are
104      * available.
105      */
106     public synchronized Connection getConnection() throws SQLException {
107     	if (checkedOut != null) {
108     		throw checkedOut;
109     	}
110 
111 		String user = System.getProperty(PROP_DATABASE_USER);
112 		String pass = System.getProperty(PROP_DATABASE_PASSWORD);
113 		String url = System.getProperty(PROP_DATABASE_URL);
114 
115 		if (!url.equals(dbUrl) || !pass.equals(dbPassword) || !user.equals(dbUser)) {
116 			if (connection != null) {
117 				connection.close();
118 			}
119 			connection = DriverManager.getConnection(url, user, pass);
120 			dbUrl = url;
121 			dbPassword = pass;
122 			dbUser = user;
123 		}
124 		
125 		checkedOut = new SQLException("COnnection already checked out");
126 		return connection;
127     }
128 
129 
130     /**
131      * Used to return an HL7 normative database connection to the connection pool. If the given
132      * connection is not in fact a connection to the normative database, it is discarded.
133      */
134     public void returnConnection(Connection conn) {
135     	checkedOut = null;
136     }
137 
138 
139     // test
140     public static void main(String[] args) {
141         try {
142             Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
143             Connection conn = NormativeDatabase.getInstance().getConnection();
144             Statement stmt = conn.createStatement();
145             ResultSet rs = stmt.executeQuery("select * from TableValues");
146             while (rs.next()) {
147                 Object tabNum = rs.getObject(1);
148                 Object val = rs.getObject(3);
149                 Object desc = rs.getObject(4);
150                 System.out.println("Table: " + tabNum + " Value: " + val + " Description: " + desc);
151             }
152         } catch (SQLException e) {
153             log.error("test msg!!", e);
154         } catch (ClassNotFoundException e) {
155             log.error("test msg!!", e);
156         }
157     }
158 
159 }