Android Open Source - DKO Reflected Data Source

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Back to project page DKO.
License

The source code is released under:
GNU Lesser General Public License
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Java Source Code

package org.kered.dko.datasource;
/*from   ww  w  .  j ava 2s. c om*/
import java.io.PrintWriter;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.SQLFeatureNotSupportedException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.logging.Logger;

import javax.sql.DataSource;

/**
 * This class will, given a class name and a method, call that method to get an
 * actual {@code javax.sql.DataSource}. &nbsp; It is then cached, and all other calls
 * are passed through.
 *
 * @author Derek Anderson
 */
public class ReflectedDataSource implements MatryoshkaDataSource {

  private static final Logger log = Logger.getLogger("org.kered.dko.ReflectedDataSource");

  DataSource ds = null;
  private final String cls;
  private final String method;
  private String schema = null;
  StackTraceElement[] st = Thread.currentThread().getStackTrace();

  public ReflectedDataSource(final String cls, final String method) {
    this.cls = cls;
    this.method = method;
  }

  public ReflectedDataSource(final String cls, final String method, final String schema) {
    this.cls = cls;
    this.method = method;
    this.schema  = schema;
  }

  private void checkDS() {
    if (ds != null) return;
    try {
      Method m = null;
      if (schema == null) {
        m = Class.forName(cls).getMethod(method);
        ds = (DataSource) m.invoke(null);
      } else {
        m = Class.forName(cls).getMethod(method, String.class);
        ds = (DataSource) m.invoke(null, schema);
      }
      //System.err.println("ds: "+ ds);
    } catch (final Exception e) {
      log.severe("could not access "+ cls +"."+ method +": "+ e.getMessage());
      throw new RuntimeException(e);
    }
    if (ds==null) throw new RuntimeException("Method "+ cls +"."+ method +" returned a null DataSource.  "
        +"ReflectedDataSource created at:\n\t\t"+ Util.join("\n\t\t", st));
  }

  @Override
  public PrintWriter getLogWriter() throws SQLException {
    checkDS();
    return ds.getLogWriter();
  }

  @Override
  public int getLoginTimeout() throws SQLException {
    checkDS();
    return ds.getLoginTimeout();
  }

  @Override
  public void setLogWriter(final PrintWriter arg0) throws SQLException {
    checkDS();
    ds.setLogWriter(arg0);
  }

  @Override
  public void setLoginTimeout(final int arg0) throws SQLException {
    checkDS();
    ds.setLoginTimeout(arg0);
  }

  @Override
  public boolean isWrapperFor(final Class<?> arg0) throws SQLException {
    checkDS();
    if (ds==null) return false;
    if (ds.getClass().equals(arg0)) return true;
    return ds.isWrapperFor(arg0);
  }

  @SuppressWarnings("unchecked")
  @Override
  public <T> T unwrap(final Class<T> arg0) throws SQLException {
    checkDS();
    if (ds.getClass().equals(arg0)) return (T) ds;
    return ds.unwrap(arg0);
  }

  @Override
  public Connection getConnection() throws SQLException {
    checkDS();
    return ds.getConnection();
  }

  @Override
  public Connection getConnection(final String arg0, final String arg1)
      throws SQLException {
    checkDS();
    return ds.getConnection(arg0, arg1);
  }

  public DataSource getUnderlyingDataSource() {
    checkDS();
    return ds;
  }

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

  @Override
  public DataSource getPrimaryUnderlying() {
    checkDS();
    return ds;
  }

  @Override
  public Collection<DataSource> getAllUnderlying() {
    checkDS();
    final Collection<DataSource> ret = new ArrayList<DataSource>(1);
    ret.add(ds);
    return ret;
  }

}
Java Source Code List
