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Java > Open Source Codes > org > webdocwf > util > loader > DBConnectionManager


1 /*
2   Loader - tool for transfering data from one JDBC source to another and
3   doing transformations during copy.
4     Copyright (C) 2002-2003 Together
5     This library is free software; you can redistribute it and/or
6     modify it under the terms of the GNU Lesser General Public
7     License as published by the Free Software Foundation; either
8     version 2.1 of the License, or (at your option) any later version.
9     This library is distributed in the hope that it will be useful,
10     but WITHOUT ANY WARRANTY; without even the implied warranty of
11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12     Lesser General Public License for more details.
13     You should have received a copy of the GNU Lesser General Public
14     License along with this library; if not, write to the Free Software
15     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
16  Loader.java
17  Date: 03.03.2003.
18  @version 2.1 alpha
19  @authors:
20  Milosevic Sinisa sinisa@prozone.yu
21  Radoslav Dutina rale@prozone.co.yu
22  */
23
24 package org.webdocwf.util.loader;
25
26 import java.io.*;
27 import java.util.*;
28 import java.sql.*;
29
30 /**
31  * DBConnectionManager class creates all connection to database.
32  * @author Radoslav Dutina
33  * @version 1.0
34  */
35 public class DBConnectionManager {
36   private Vector drivers=new Vector();
37   private Hashtable pools=new Hashtable();
38   private static DBConnectionManager instance; // The single instance
39 private Hashtable openConnections=new Hashtable();
40   private Vector allConnectons=new Vector();
41
42   public String JavaDoc loaderJobPath="";
43   public String JavaDoc connectinPrefix="";
44   public boolean fileSystemDatabase=false;
45
46
47   /**
48    * This method set all connection into vector
49    * @param allConnections represents all connection property
50    */
51   public DBConnectionManager(Vector allConnections) {
52     this.allConnectons=allConnections;
53     init();
54   }
55
56
57   /**
58    * This method set path to LoaderJob.olj file
59    * @param loaderJob represents string path to LoaderJob.olj file
60    */
61   public void setLoaderJobPath(String JavaDoc loaderJob){
62     File file=new File(loaderJob);
63     this.loaderJobPath=file.getAbsoluteFile().getParent()+System.getProperty("file.separator");
64   }
65
66   /**
67    * This method set connection prefix
68    * @param prefix is value of connection prefix
69    */
70   public void setConnectionPrefix(String JavaDoc prefix){
71     this.connectinPrefix=prefix;
72   }
73
74   /**
75    * This method set the value of fileSystemDatabase parameter
76    * @param doParse is value of parameter
77    */
78   public void setParsePermission(boolean doParse){
79     this.fileSystemDatabase=doParse;
80   }
81
82   /**
83    * This method initialized DBConnectionManager object
84    */
85   private void init(){
86
87     loadDrivers(allConnectons);
88     createPools(allConnectons);
89   }
90
91   private void loadDrivers(Vector allConnectons){
92     if(allConnectons.size()!=0){
93       for(int i=0;i<allConnectons.size();i=i+4){
94         if(i>3){
95           if(allConnectons.get(i).toString().equalsIgnoreCase(allConnectons.get(i-4).toString())){
96             //do nothing
97 }else{
98             try{
99               Driver driver=(Driver)Class.forName(allConnectons.get(i).toString()).newInstance();
100               DriverManager.registerDriver(driver);
101               drivers.add(driver);
102             }catch(Exception JavaDoc e){
103               e.getMessage();
104             }
105           }
106         }else{
107           try{
108             Driver driver=(Driver)Class.forName(allConnectons.get(i).toString()).newInstance();
109             DriverManager.registerDriver(driver);
110             drivers.add(driver);
111           }catch(Exception JavaDoc e){
112             e.getMessage();
113           }
114         }
115       }
116     }
117   }
118
119   private void createPools(Vector allConnectons){
120     for(int i=0;i<allConnectons.size();i=i+4){
121         String JavaDoc url=allConnectons.get(i+1).toString();
122         if(url.indexOf("jdbc:microsoft:sqlserver")!=-1) {
123             if(url.indexOf("SelectMethod")==-1) {
124                 url = url+";SelectMethod=cursor";
125             }
126         }
127       String JavaDoc poolName=url;
128       String JavaDoc user=allConnectons.get(i+2).toString();
129       String JavaDoc password=allConnectons.get(i+3).toString();
130       boolean check=false;
131       if(pools.size()>0){
132         check=pools.containsKey(poolName);
133       }
134       if(!check){
135         DBConnectionPool pool=new DBConnectionPool(poolName,url,user,password);
136         pools.put(poolName,pool);
137       }
138     }
139   }
140
141   /**
142    * This method get connection from connection pool
143    * @param name is the name of the pool
144    * @return connection
145    */
146   public Connection getConnection(String JavaDoc name){
147     DBConnectionPool pool=(DBConnectionPool)pools.get(name);
148     if(pool!=null){
149       return pool.getConnection();
150     }
151     return null;
152   }
153
154   /**
155    * This method release (close) all connection and deregister all drivers
156    * @param exception defines if application calls release from exception method or not
157    */
158   public void release(String JavaDoc exception){
159     Enumeration allPools=pools.elements();
160     while(allPools.hasMoreElements()){
161       DBConnectionPool pool=(DBConnectionPool)allPools.nextElement();
162       pool.release(exception);
163     }
164     Enumeration allDrivers=drivers.elements();
165     while(allDrivers.hasMoreElements()){
166       Driver driver=(Driver)allDrivers.nextElement();
167       try{
168         DriverManager.deregisterDriver(driver);
169       }catch(Exception JavaDoc e){
170         e.getMessage();
171       }
172     }
173   }
174
175   private class DBConnectionPool{
176     private String JavaDoc name=null;
177     private String JavaDoc url=null;
178     private String JavaDoc user=null;
179     private String JavaDoc password=null;
180
181
182     /**
183      * Construct the object of DBConnectionPool class with associated parameters
184      * @param name is the name of the connection
185      * @param url is url to database which we wont to connect
186      * @param user is the user name
187      * @param password is user password
188      */
189     public DBConnectionPool(String JavaDoc name,String JavaDoc url,String JavaDoc user,String JavaDoc password){
190       this.name=name;
191       this.url=url;
192       this.user=user;
193       this.password=password;
194
195     }
196
197     /**
198      * This method return connection if the connection exists, or create new connection
199      * if don't
200      * @return connection
201      */
202     public Connection getConnection(){
203       Connection conn=null;
204       if(openConnections.size()>0){
205         conn=(Connection)openConnections.get(name);
206         if(conn!=null){
207           return conn;
208         }
209         conn=newConnections();
210       }else{
211         conn=newConnections();
212       }
213       return conn;
214     }
215
216     private Connection newConnections(){
217       Connection conn=null;
218        url=Utils.getAbsolutePathFromDatabaseURL(connectinPrefix,loaderJobPath,
219            url,fileSystemDatabase);
220       try{
221         if(user==null){
222           conn=DriverManager.getConnection(url);
223           openConnections.put(name,conn);
224         }else{
225           conn=DriverManager.getConnection(url,user,password);
226           openConnections.put(name,conn);
227         }
228
229       }catch(Exception JavaDoc e){
230         e.printStackTrace();
231       }
232       return conn;
233     }
234
235     /**
236      * This method close and commit connection
237      * @param exception defines if application calls release from exception method or not
238      */
239     public void release(String JavaDoc exception){
240       Connection conn=(Connection)openConnections.get(name);
241       try{
242         if(!conn.isClosed()){
243           if(exception.equalsIgnoreCase("false"))
244             conn.commit();
245           conn.close();
246         }
247         openConnections.remove(name);
248       }catch(Exception JavaDoc e){
249         e.getMessage();
250       }
251     }
252
253   }
254 }
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