Android Open Source - DKO Single Connection Data Source

From Project

Back to project page DKO.
License

The source code is released under:
GNU Lesser General Public License
If you think the Android project DKO listed in this page is inappropriate, such as containing malicious code/tools or violating the copyright, please email info at java2s dot com, thanks.
Java Source Code

package org.kered.dko.datasource;
//w  w  w.j av  a 2  s.  c om
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.SQLFeatureNotSupportedException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.logging.Logger;

import javax.sql.DataSource;

/**
 * Fakes a {@code DataSource} to only ever use one (continuously open) connection. &nbsp;
 * Intercepts all calls to close the connection.
 * <p>
 * User is responsible for eventually closing the original connection.
 *
 * @author dander
 */
public class SingleConnectionDataSource implements DataSource {

  private final Connection conn;
  private final Lock lock = new ReentrantLock();
  private int timeout = 10;
  private static final Logger log = Logger.getLogger("org.kered.dko.datasource.SingleConnectionDataSource");

  public SingleConnectionDataSource(final Connection conn) {
    this.conn = new UnClosableConnection(conn, new UnClosableConnection.CloseListener() {
      @Override
      public void wasClosed(final UnClosableConnection c) {
        lock.unlock();
      }
    });
  }
  
  public SingleConnectionDataSource(final Connection conn, int timeout) {
    this(conn);
    this.timeout = timeout;
  }

  @Override
  public PrintWriter getLogWriter() throws SQLException {
    // TODO Auto-generated method stub
    return null;
  }

  @Override
  public void setLogWriter(final PrintWriter out) throws SQLException {
    // TODO Auto-generated method stub

  }

  @Override
  public void setLoginTimeout(final int seconds) throws SQLException {
    // TODO Auto-generated method stub

  }

  @Override
  public int getLoginTimeout() throws SQLException {
    // TODO Auto-generated method stub
    return 0;
  }

  @Override
  public <T> T unwrap(final Class<T> iface) throws SQLException {
    // TODO Auto-generated method stub
    return null;
  }

  @Override
  public boolean isWrapperFor(final Class<?> iface) throws SQLException {
    // TODO Auto-generated method stub
    return false;
  }

  @Override
  public Connection getConnection() throws SQLException {
    try {
      if (lock.tryLock(timeout, TimeUnit.SECONDS)) return conn;
      throw new SQLException("unable to aquire connection lock after "+ timeout +" seconds");
    } catch (final InterruptedException e) {
      e.printStackTrace();
      return null;
    }
  }

  @Override
  public Connection getConnection(final String username, final String password) throws SQLException {
    try {
      if (lock.tryLock(timeout, TimeUnit.SECONDS)) return conn;
      throw new SQLException("unable to aquire connection lock after "+ timeout +" seconds");
    } catch (final InterruptedException e) {
      e.printStackTrace();
      return null;
    }
  }

  //@Override
  public Logger getParentLogger() throws SQLFeatureNotSupportedException {
    throw new SQLFeatureNotSupportedException();
  }

  @Override
  public int hashCode() {
      final int prime = 31;
      int result = 1;
      result = prime * result + ((conn == null) ? 0 : conn.hashCode());
      result = prime * result + timeout;
      return result;
  }

  @Override
  public boolean equals(Object obj) {
      if (this == obj)
    return true;
      if (obj == null)
    return false;
      if (getClass() != obj.getClass())
    return false;
      SingleConnectionDataSource other = (SingleConnectionDataSource) obj;
      if (conn == null) {
    if (other.conn != null)
        return false;
      } else if (!conn.equals(other.conn))
    return false;
      if (timeout != other.timeout)
    return false;
      return true;
  }

}
Java Source Code List
