Direct JDBC calls, local transaction

This can group several statements in a unit of work with setAutoCommit set to false, as shown in Example 12-2.

Example 12-2 StaleConnectionException with direct JDBC calls and local transaction

...

	javax.sql.DataSource ds=null;

	java.sql.Connection conn=null;

	java.sql.Statement stmt1=null;

	java.sql.ResultSet rs=null;

	int maxRetries=5; // set maximum number of retries

	int noRetries=0;

	int bal=0;

	boolean retry=false;

	do {

		try { //already lookup datasource object ds, see above section

			conn=ds.getConnection();

			conn.setAutoCommit(false);

			stmt1=conn.createStatement();

			rs=stmt1.executeQuery(sqlstring1);

			bal=rs.getInt(3);

			stmt1.executeUpdate(sqlstring2);

			conn.commit();

		} catch ( com.ibm.websphere.ce.cm.StaleConnectionException staleex) {

			//rollback

			try{

				conn.rollback();

				if (noRetries <= maxRetries) {

					// retry upto maxRetries times

					try {

						Thread.sleep(1000 + 20000*noRetries);

						// with increasing retry interval

						// preserve cpu cycle

					} catch (InterruptedException iex) {

						System.out.println(

							"Sleep Interruppted" + iex.getMessage());

					}

					noRetries++;

					retry=true;

				} else {

					retry=false;

					// don't retry after maxRetries times

				}

			} catch (Exception ex) {

				retry=false;

				//rollback failed, don't retry

			}

		} catch (java.sql.SQLException sqlex) {

			//other sql exception, don't retry

			retry=false;

		} catch ( Exception ex) {

			// generic exception, don't retry

			retry=false;

		} finally {

			try {

				if (rs!=null) rs.close();

				if (stmt1!=null) stmt1.close();

				if (conn!=null) conn.close();

			} catch (Exception ex) {}

		}

	} while (retry);

...

  Prev | Home | Next

 

WebSphere is a trademark of the IBM Corporation in the United States, other countries, or both.

 

IBM is a trademark of the IBM Corporation in the United States, other countries, or both.