readxml.java

此为连接池实现程序

package com.sunrise.chnl.obj;

import java.io.IOException;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
import org.w3c.dom.DOMException;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;

public class ReadXml {
  public ReadXml() {
  }

  /**
   * @param p_xml_file xml文件全名
   * @return
   * @throws java.lang.Exception
   */
  public Document getDocument(String p_xml_file) throws Exception {
    //为解析XML作准备，创建DocumentBuilderFactory实例,指定DocumentBuilder
    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    DocumentBuilder db = null;
    try {
      db = dbf.newDocumentBuilder();
    }
    catch (ParserConfigurationException pce) {
      return null;
    }
    Document doc = null;
    try {
      doc = db.parse(p_xml_file);
    }
    catch (DOMException dom) {
      System.err.println(dom.getMessage());
      return null;
    }
    catch (IOException ioe) {
      return null;
    }
    return doc;
  }

  /**
   * @param doc
   * @param p_tag 读取标志段
   * @param p_item 读取参数
   * @return 参数值
   * @throws java.lang.Exception
   */
  public String getConfig(Document doc,String p_tag,String p_item) throws Exception {
    //下面是解析XML的全过程，先取根元素
    Element root = doc.getDocumentElement();
    NodeList tags = root.getElementsByTagName(p_tag);
    for (int i = 0; i < tags.getLength(); i++) {
      //依次取每个元素
      Element element = (Element) tags.item(i);
      NodeList items = element.getElementsByTagName(p_item);
      if (items.getLength() > 0){
        Element e = (Element) items.item(0);
        Text t = (Text) e.getFirstChild();
        return t.getNodeValue();
      }
    }
    return "";
  }

  /**
   * @param doc
   * @param p_tag 读取标志段
   * @param p_ds_name 读取的datasource名称
   * @param p_item 读取参数
   * @return 参数值
   * @throws java.lang.Exception
   */
  public String getConfig(Document doc,String p_tag,String p_ds_name,String p_item) throws Exception {
    //下面是解析XML的全过程，先取根元素
    Element root = doc.getDocumentElement();
    NodeList tags = root.getElementsByTagName(p_tag);
    for (int i = 0; i < tags.getLength(); i++) {
      //依次取每个元素
      Element element = (Element) tags.item(i);
      String s_ds_name = element.getAttribute("name").trim();
      if(s_ds_name.equals(p_ds_name)){
        NodeList items = element.getElementsByTagName(p_item);
        if (items.getLength() > 0){
          Element e = (Element) items.item(0);
          Text t = (Text) e.getFirstChild();
          return t.getNodeValue();
        }
      }
    }
    return "";
  }
}