UseUnpooledDataSource


1   import java.sql.*;
2   import javax.sql.DataSource  ;
3   import com.mchange.v2.c3p0.DataSources;
4   
5   
6   /**
7    *  This example shows how to programmatically get and directly use
8    *  an unpooled DataSource
9    */
10  public final class UseUnpooledDataSource
11  {
12  
13      public static void main(String  [] argv)
14      {
15      try
16          {
17  
18          // Note: your JDBC driver must be loaded [via Class.forName( ... ) or -Djdbc.properties]
19          // prior to acquiring your DataSource!
20  
21          // Acquire the DataSource... this is the only c3p0 specific code here
22          DataSource   ds = DataSources.unpooledDataSource("jdbc:postgresql://localhost/test",
23                                     "swaldman",
24                                     "test");
25  
26          // get hold of a Connection an do stuff, in the usual way
27          Connection con  = null;
28          Statement  stmt = null;
29          ResultSet  rs   = null;
30          try
31              {
32              con = ds.getConnection();
33              stmt = con.createStatement();
34              rs = stmt.executeQuery("SELECT * FROM foo");
35              while (rs.next())
36                  System.out.println( rs.getString(1) );
37              }
38          finally
39              {
40              //i try to be neurotic about ResourceManagement,
41              //explicitly closing each resource
42              //but if you are in the habit of only closing
43              //parent resources (e.g. the Connection) and
44              //letting them close their children, all
45              //c3p0 DataSources will properly deal.
46              attemptClose(rs);
47              attemptClose(stmt);
48              attemptClose(con);
49              }
50          }
51      catch (Exception   e)
52          { e.printStackTrace(); }
53      }
54  
55      static void attemptClose(ResultSet o)
56      {
57      try
58          { if (o != null) o.close();}
59      catch (Exception   e)
60          { e.printStackTrace();}
61      }
62  
63      static void attemptClose(Statement o)
64      {
65      try
66          { if (o != null) o.close();}
67      catch (Exception   e)
68          { e.printStackTrace();}
69      }
70  
71      static void attemptClose(Connection o)
72      {
73      try
74          { if (o != null) o.close();}
75      catch (Exception   e)
76          { e.printStackTrace();}
77      }
78  
79      private UseUnpooledDataSource()
80      {}
81  }
82
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