JndiConfiguration.java

package org.opensource.clearpool.configuration;

import java.util.Hashtable;

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

import org.opensource.clearpool.exception.ConnectionPoolException;
import org.opensource.clearpool.exception.ConnectionPoolXMLParseException;
import org.opensource.clearpool.logging.PoolLogger;
import org.opensource.clearpool.logging.PoolLoggerFactory;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

/**
 * How to parse jndi.
 *
 * @author xionghui
 * @date 16.08.2014
 * @version 1.0
 */
public class JndiConfiguration {
  private static final PoolLogger LOGGER = PoolLoggerFactory.getLogger(JndiConfiguration.class);

  private final static String JNDI_NAME = "jndi-name";
  private final static String PROP = "prop";
  private final static String KEY = "key";

  public static CommonDataSource parse(Element element) {
    String jndiName = null;
    Hashtable<String, String> environment = new Hashtable<String, String>();

    NodeList children = element.getChildNodes();
    for (int i = 0, size = children.getLength(); i < size; i++) {
      Node childNode = children.item(i);
      if (childNode instanceof Element) {
        Element child = (Element) childNode;
        String nodeName = child.getNodeName();
        String nodeValue = child.getTextContent().trim();
        if (JNDI_NAME.equals(nodeName)) {
          if (jndiName != null) {
            throw new ConnectionPoolException(JndiConfiguration.JNDI_NAME + " repeat");
          }
          jndiName = nodeValue;
        } else if (PROP.equals(nodeName)) {
          String key = child.getAttributeNode(KEY).getNodeValue();
          environment.put(key, nodeValue);
        }
      }
    }
    return getDataSource(jndiName, environment);
  }

  /**
   * Get dataSource by jndiName and environment.
   */
  private static CommonDataSource getDataSource(String jndiName,
      Hashtable<String, String> environment) {
    if (jndiName == null) {
      throw new ConnectionPoolXMLParseException(JNDI_NAME + " is illegal");
    }
    CommonDataSource ds;
    try {
      Context initial = new InitialContext(environment);
      ds = (CommonDataSource) initial.lookup(jndiName);
    } catch (NamingException e) {
      LOGGER.error("getDataSource error: ", e);
      throw new ConnectionPoolException(e);
    }
    return ds;
  }
}