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Editorial Team
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Asked: 2026-05-29T08:12:42+00:00

I have set up jdbc connection pooling in a java-ee environment by doing the

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I have set up jdbc connection pooling in a java-ee environment by doing the following changes.

    The context.xml 

<Context> 
        <Resource name="jdbc/mysybase" auth="Container" 
                  type="javax.sql.DataSource" driverClassName="com.sybase.jdbc3.jdbc.SybDriver" 
                  url="jdbc:sybase:Tds:H2S33.studtrack.com:2025/student" 
                  username="scott" password="tiger" maxActive="20" maxIdle="10" 
                  maxWait="-1"/> 
    </Context> 


    In The web.xml file 
    <resource-ref> 
     <description>Sybase Datasource example</description> 
     <res-ref-name>jdbc/mysybase</res-ref-name> 
     <res-type>javax.sql.DataSource</res-type> 
     <res-auth>Container</res-auth> 
    </resource-ref> 


    And the jsp page 

    <%@page import="java.sql.*"%> 
    <%@page import="javax.naming.Context"%> 
    <%@page import="javax.naming.InitialContext"%> 
    <%@page import="java.sql.Connection"%> 
    <%@page import="java.sql.SQLException"%> 
    <%@page import="java.sql.ResultSet"%> 
    <%@page import="javax.sql.DataSource"%> 
    <html> 
    <head> 
    <title>Obtaining a Connection</title> 
    </head> 
    <body> 

    <% 
        Connection conn = null; 
        ResultSet result = null; 
        Statement stmt = null; 
         try { 
           Context initContext = new InitialContext(); 
        Context envContext  = (Context)initContext.lookup("java:/comp/env"); 
           DataSource ds = (DataSource)envContext.lookup("jdbc/mysybase"); 
           conn = ds.getConnection(); 
        if (conn != null)  
        { 
            String message = "Got Connection " + conn.toString() + ", "; 
            out.write(message); 
        } 
        else 
        { 
            out.write("hello no conn obtained"); 

        } 

            stmt = conn.createStatement(); 
            result = stmt.executeQuery("SELECT * FROM Student"); 
        while(result.next()) 
        { 
            out.write(result.getString("name")); 
        } 

         } 
         catch (SQLException e) { 
             out.write("Error occurred " + e); 
          } 

    %> 

    </body> 
    </html>

Now i want the jdbc pooling to be available in normal java classes as well.
Do i need to make any changes if i want the pooling to be available in java classes.
Can i get a connection object in a java class just as i got the connection in the jsp as shown above.

Connection conn = null; 
ResultSet result = null; 
Statement stmt = null;
Context initContext = new InitialContext(); 
Context envContext  = (Context)initContext.lookup("java:/comp/env"); 
DataSource ds = (DataSource)envContext.lookup("jdbc/mysybase"); 
conn = ds.getConnection();
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1 Answer

  1. Editorial Team

    1.) You can set a contextListener to initialize connection only once and get logical conn from the pool (gues you use tomcat’s DBCP).

    2.) Yes, once you start a connection (driver sets a socket and the pool gets initialized) from context data, you can get a connection (from the pool) properly invoking that from any java class.

    3.) Try not to put pure Java code in JSPs. Just a rule of the road: is treated as a poor decision.

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