Tomcat Connection Pools

asked 2014-06-25 09:56:48 +0800

IngoB
256 ● 6

Hi,

I want to use the Tomcat Connection Pool to handle ZK's DB Connections. I tried it with 5 maxActive (testcase), BUT AFTER! 4x doSQL() calls ZK is doing "nothing" and showing "progressing" ... I have to handle 200 Connections at the same time, so why is ZK/Tomcat not handling more than 5 connections?

Any help appreciated :/

------- CODE ------------

So I got Eclipse Kepler SR2 + Tomcat 6.0.

I added a "context.xml" to the /META-INF Folder

<?xml version="1.0" encoding="UTF-8"?>
<Context>
    <Resource name="jdbc/localdb" auth="Container"
        type="javax.sql.DataSource" username="a" password="b"
        driverClassName="org.postgresql.Driver"
        url="jdbc:postgresql://localhost:5432/mydb"
        maxActive="5" maxIdle="1" />
</Context>

I created a class for the DataConnection

public class DataConnection {
    private DataSource dataSource;
    public DataConnection() {
    }

    private void connectToDataBase() {
        try {
            Context initContext = new InitialContext();
            Context envContext = (Context) initContext.lookup("java:/comp/env");
            dataSource = (DataSource) envContext.lookup("jdbc/localdb");
        } catch (NamingException e) {
            e.printStackTrace();
        }
    }

    public Connection getConnection() {
        try {
            if (dataSource == null || dataSource.getConnection().isClosed()) {
                connectToDataBase();
            }
            return dataSource.getConnection();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return null;
    }

}

And i tried a preparedStatement

private DataConnection dataConnection;

@Init
public void init() {
    dataConnection = new DataConnection();
}

private void doSQL(int pk) {
        ResultSet resultSet = null;
        PreparedStatement preparedStatement = null;
        Connection connection = null;
        try {
            String selectSQL = "SELECT * FROM myTable WHERE pk=?";
            connection = dataConnection.getConnection();
            preparedStatement = connection.prepareStatement(selectSQL);
            preparedStatement.setInt(1, pk);

            resultSet = preparedStatement.executeQuery();

            while (resultSet.next()) {
                System.out.println(resultSet.getString("name"));
            }

        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                if (null != resultSet) {
                    resultSet.close();
                    System.out.println("resultSet.close();");
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
            try {
                if (null != preparedStatement) {
                    preparedStatement.close();
                    System.out.println("preparedStatement.close();");
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
            try {
                if (null != connection) {
                    connection.close();
                    System.out.println("connection.close();");
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }