ログ4 jにデータソースをサポートさせる

package gfsoft.his.util;

import java.sql.Connection;
import java.sql.SQLException;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.sql.DataSource;

import org.apache.log4j.jdbc.JDBCAppender;
import org.apache.log4j.spi.ErrorCode;

/**
 *   JDBCAppender，       
 *         ：
 * 1、     ：  JNDI      ，      
 * 2、     ：     LOG4J       ，        ，
 *            
 */
public class JNDIAppender extends JDBCAppender  {
  private String jndiName;

  public String getJndiName() {
    return jndiName;
  }

  public void setJndiName(String jndiName) {
    this.jndiName = jndiName;
  }
  
  /**
   *   JNDI     
   */
  private DataSource lookupDataSource(){
    try {
      Context context = new InitialContext();
      return (DataSource) context.lookup(getJndiName());
    } catch (NamingException e) {
      throw new RuntimeException("Cannot find JNDI DataSource: " + getJndiName(), e);
    }
  }
  
  /**
   *          
   */
  protected Connection getConnection() throws SQLException {
    if (getJndiName() == null) {
      return super.getConnection();
    } else {
      return lookupDataSource().getConnection();
    }
  }
  
  protected void closeConnection(Connection con) {
    try {
      con.close();
    } catch (SQLException e) {
      errorHandler.error("Failed to close connection", e, ErrorCode.CLOSE_FAILURE);
    }
  }
}