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<![CDATA[Heck's Blog]]> https://www.heckjj.com/index.php zh-cn https://www.heckjj.com/post// <![CDATA[如何在java中解析操作XML]]> Heck <@hecks.tk> Thu, 14 May 2009 11:48:02 +0000 https://www.heckjj.com/post// 这几天我把我的XML操作类整理了一下，现在共享出来。
测试环境：jdk 1.6+Eclipse 5.5GA
第三方类库：dom4j-1.6.1
代码：

package com.gaylys.utils.filehandler.xml;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;
import org.dom4j.Attribute;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.Node;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;
public class XmlHandler {
  private Document document = null;
  // 要解析的xml文档路径
  private String xmlUrl = null;
  public void setXmlUrl(String url) {
    this.xmlUrl = url;
  }
  public String getXmlUrl() {
    return this.xmlUrl;
  }
  public XmlHandler(String xmlUrl) {
    super();
    this.xmlUrl = xmlUrl;
    this.document = parse(xmlUrl);
  }
  /**
   * 解析xml
   *
   * @param url
   *      xml文档地址 "com/gaylys/utils/test/analysis/test.xml"
   * @return 返回文档对象
   * @throws DocumentException
   */
  public Document parse(String url) {
    SAXReader reader = new SAXReader();
    Document document = null;
    try {
      document = reader.read(url);
      if (this.xmlUrl == null || "".equals(this.xmlUrl)) {
        this.xmlUrl = url;
      }
      this.document = document;
    } catch (DocumentException e) {
      e.printStackTrace();
    }
    return document;
  }
  /**
   * 根据XPath路径得到节点值(包括属性)，确保此路径对应的节点在文档中是唯一的。
   *
   * @param XPath
   *      节点路径 元素节点形如：//catalog/journal，属性节点形如：//catalog/journal/@title
   * @return 返回对应节点的值
   */
  public String getSingleNodeValue(String XPath) {
    String value = null;
    if (XPath == null || "".equals(XPath)) {
    } else {
      if (XPath.substring(XPath.length() - 1) == "/"
          || "/".equals(XPath.substring(XPath.length() - 1))) {
        XPath = XPath.substring(0, XPath.length() - 1);
      }
      if (!XPath.startsWith("/", 1)) {
        if (!XPath.startsWith("/", 0)) {
          XPath = "//" + XPath;
        }
      }
      Node node = document.selectSingleNode(XPath);
      value = node.getText();
    }
    return value;
  }
  /**
   * 根据节点的路径XPath和其值修改此节点的值，因为可能有多个节点路径相同的节点，所以以节点值来确定节点唯一性。
   *
   * @param XPath
   *      节点路径
   * @param oldValue
   *      对应节点修改前的值
   * @param newvalue
   *      要修改的值
   */
  public void updateNodeValue(String XPath, String oldvalue, String newvalue) {
    try {
      Document doc = this.document;
      if (XPath == null || "".equals(XPath) || oldvalue == null
          || "".equals(oldvalue) || newvalue == null
          || "".equals(newvalue)) {
        System.err.println("请检查传入的参数！");
        return;
      } else {
        if (oldvalue == newvalue || oldvalue.equals(newvalue)) {
          System.err.println("修改前的节点值与修改后的节点值相同，不需要修改");
        } else {
          if (XPath.substring(XPath.length() - 1) == "/"
              || "/".equals(XPath.substring(XPath.length() - 1))) {
            XPath = XPath.substring(0, XPath.length() - 1);
          }
          if (!XPath.startsWith("/", 1)) {
            if (!XPath.startsWith("/", 0)) {
              XPath = "//" + XPath;
            }
          }
          List list = doc.selectNodes(XPath);
          Iterator it = list.iterator();
          while (it.hasNext()) {
            Element ele = (Element) it.next();
            if (ele.getText().equals(oldvalue)) {
              ele.setText(newvalue);
            } else {
              System.err.println("找不到与节点值为" + oldvalue + "的节点"
                  + XPath);
              return;
            }
          }
          XMLWriter writer = new XMLWriter(new FileWriter(new File(
              xmlUrl)));
          writer.write(doc);
          writer.close();
          System.out.println("成功将" + XPath + "节点的值修改为 : " + newvalue);
        }
      }
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
  /**
   * 根据属性的路径XPath和其值修改此属性的值，因为可能有多个属性路径相同的属性，所以以属性值来确定属性唯一性。
   *
   * @param XPath
   *      属性的路径
   * @param oldvalue
   *      对应属性修改前的值
   * @param newvalue
   *      要修改的值
   */
  public void updateAttributeValue(String XPath, String oldvalue,
      String newvalue) {
    try {
      Document doc = this.document;
      if (XPath == null || "".equals(XPath) || oldvalue == null
          || "".equals(oldvalue) || newvalue == null
          || "".equals(newvalue)) {
        System.err.println("请检查传入的参数！");
        return;
      } else {
        if (oldvalue == newvalue || oldvalue.equals(newvalue)) {
          System.err.println("修改前的属性值与修改后的属性值相同，不需要修改");
        } else {
          if (XPath.substring(XPath.length() - 1) == "/"
              || "/".equals(XPath.substring(XPath.length() - 1))) {
            XPath = XPath.substring(0, XPath.length() - 1);
          }
          if (!XPath.startsWith("/", 1)) {
            if (!XPath.startsWith("/", 0)) {
              XPath = "//" + XPath;
            }
          }
          List list = doc.selectNodes(XPath);
          Iterator it = list.iterator();
          while (it.hasNext()) {
            Attribute att = (Attribute) it.next();
            if (att.getText().equals(oldvalue)) {
              att.setText(newvalue);
            } else {
              System.err.println("找不到与属性值为" + oldvalue + "的属性"
                  + XPath);
              return;
            }
          }
          XMLWriter writer = new XMLWriter(new FileWriter(new File(
              xmlUrl)));
          writer.write(doc);
          writer.close();
          System.out.println("成功将" + XPath + "属性的值修改为 : " + newvalue);
        }
      }
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
}

　这个类用到了XPath，可以进这个网站看看语法。
　　如果遇到异常：java.lang.NoClassDefFoundError: org/jaxen/JaxenException，看我的另一篇日志：java异常及解决方案集合。

Tags - java , 解析xml , 操作xml ]]> https://www.heckjj.com/post//#blogcomment <![CDATA[[评论] 如何在java中解析操作XML]]> <user@domain.com> Thu, 01 Jan 1970 00:00:00 +0000 https://www.heckjj.com/post//#blogcomment