How can I set a connection property?

Question

I can connect fine to an Oracle 11.2 database using JDBC driver and the following Java code:

  import java.sql.*;
  import javax.sql.DataSource;
  import javax.naming.Context;
  import javax.naming.InitialContext;
  import javax.naming.NamingException;
  import oracle.jdbc.OracleTypes;
  ...
  Connection conn=null;

  // connect to database
  Context context = new InitialContext();
  DataSource ds = (DataSource)context.lookup("jdbc/myPool");
  conn = ds.getConnection();

But now I need to set the option SetFloatAndDoubleUseBinary to true. See page 4-16 here

http://docs.oracle.com/cd/E14072_01/java.112/e10589.pdf

So I try to follow examples from here:

http://docs.oracle.com/cd/E11882_01/java.112/e16548/urls.htm

and I modify the code as:

  import java.sql.*;
  import java.util.Properties;
  import javax.sql.DataSource;
  import javax.naming.Context;
  import javax.naming.InitialContext;
  import javax.naming.NamingException;
  import oracle.jdbc.OracleTypes;
  ...
  Connection conn=null;

  // set connection properties
  Properties info = new java.util.Properties();
  info.put ("SetFloatAndDoubleUseBinary","true");

  // connect to database
  Context context = new InitialContext();
  DataSource ds = (DataSource)context.lookup("jdbc/myPool");
  conn = ds.getConnection(info);

and I'm getting the following compile error:

myClass.java:1145: cannot find symbol
symbol  : method getConnection(java.util.Properties)
location: interface javax.sql.DataSource
          conn = ds.getConnection(info);
                   ^

Anyone know how I can properly set SetFloatAndDoubleUseBinary here?

UPDATE 1

Changing to:

  import java.sql.*;
  import java.util.Properties;
  import javax.sql.DataSource;
  import javax.naming.Context;
  import javax.naming.InitialContext;
  import javax.naming.NamingException;
  import oracle.jdbc.OracleTypes;
  import oracle.jdbc.*;       // NEW
  import oracle.jdbc.pool.*;  // NEW
  ...
  Connection conn=null;

  // set connection properties
  Properties info = new java.util.Properties();
  info.put ("SetFloatAndDoubleUseBinary","true");

  // connect to database
  Context context = new InitialContext();
  DataSource ds = (DataSource)context.lookup("jdbc/myPool");
  ((OracleDataSource)ds).setConnectionProperties(info); // NEW
  conn = ds.getConnection();                    // NEW

gives the following run time error:

stack trace: java.lang.ClassCastException: com.sun.gjc.spi.jdbc40.DataSource40 cannot be cast to oracle.jdbc.pool.OracleDataSource

Answer 1

The DataSource is usually configured on the application server. For example, in Glassfish you could set this property in the admin console like this:

and then just call

ds.getConnection() from your client code.

Edit:

If you want to get access to the implementation class of javax.sql.DataSource, you should use DataSource#unwrap method rather than simple cast.

For example:

DataSource ds = (DataSource) ctx.lookup("jdbc/MyPool");
OracleDataSource oracleDS = ds.unwrap(OracleDataSource.class)  

Make sure, you have your jdbc driver jar on classpath.

But then your code will be non-portable, if you wish to switch to another database vendor in the future.

Edit 2:
Also, for Glassfish, refer to the Configuring Specific JDBC Connection Pool Features of Oracle Administration Guide.

Answer 2

This form of getConnection() is specific to OracleDataSource and doesn't exist in the more generic DataSource interface.

The solution is simple, replace this line:

DataSource ds = (DataSource)context.lookup("jdbc/myPool");

with this:

OracleDataSource ds = (OracleDataSource)context.lookup("jdbc/myPool");

Of course this means that from now on your application will only work with Oracle databases. Depending on what you need this may or may not be a good idea.