Java操作XML

问题描述：

        Java操作XML，包括增删查改、创建、删除基本操作

参考资料：

　　http://www.cnblogs.com/ITEagle/archive/2010/03/03/1677431.html 

问题解决：

       包含jar包文件：

     

dom4j.jar和jaxen.jar

创建、删除XML文件:XmlBuilder.java 文件

package org.xml;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

public class XmlBuilder {

    private String path; // XML保存和读取文件路径
    private Document doc; // XML文档对象
    private Element root; // XML文档根元素

    public XmlBuilder(String path) {
        this.path = path;
        doc = DocumentHelper.createDocument();
        root = null;
    }

    // 构造函数重载
    public XmlBuilder() {
        this.path = "";
        doc = DocumentHelper.createDocument();
        root = null;
    }

    // 返回XML文档对象
    public Document GetDoc() {
        return doc;
    }

    // 创建XML文件的根元素
    public Element CreateRoot(String name) {
        root = doc.addElement(name);
        return root;
    }

    // 返回XML文件根元素的名称
    public String GetRootName() {
        if (root != null) {
            return root.getName();
        }
        return null;
    }

    // 返回XML根元素
    public Element GetRoot() {
        return root;
    }

    // 设置XML文件保存或者访问的文件位置
    public void SetPath(String pathname) {
        this.path = pathname;
    }

    // 读取XML文件的private方法
    private Document readXML(String pathname) throws Exception {
        if (pathname != "") {
            SAXReader reader = new SAXReader();
            try {
                this.SetPath(pathname);
                doc = reader.read(new File(pathname));
                root = doc.getRootElement(); // 读取XML文件，同时初始化root
            } catch (DocumentException e) {
                throw new Exception("读取" + pathname + "XML文件出错！");
            }
            return doc;
        } else {
            throw new Exception("读取XML路径为空！");
        }
    }

    // 读取指定路径XML文件，返回Document对象
    public Document ReadXML(String xmlpath) throws Exception {
        this.path = xmlpath;
        return readXML(path);
    }

    // 读取已初始化路径的XML文件
    public Document ReadXML() throws Exception {
        return readXML(path);
    }

    // 保存XML文件的private方法
    private void saveXML(String savepath) throws Exception {
        if (savepath == "" || savepath == null) {
            throw new Exception("保存XML文件路径为空！");
        }

        if (doc != null) {
            try {
                OutputFormat format = OutputFormat.createPrettyPrint();
                XMLWriter wrt = new XMLWriter(new FileOutputStream(new File(
                        savepath)), format);
                wrt.write(doc);
                wrt.close();
            } catch (IOException e) {
                throw new Exception("保存" + savepath + "XML文件出错！");
            }
        } else {
            throw new Exception("Document 对象为空");
        }
    }

    // 使用自定义路径，保存XML文件
    public void SaveXML(String savepath) throws Exception {
        saveXML(savepath);
    }

    // 使用已初始化路径保存XML文件
    public void SaveXML() throws Exception {
        saveXML(path);
    }

    // XML文件输出到屏幕
    public void SaveConsole() throws Exception {
        if (doc != null) {
            try {
                OutputFormat format = OutputFormat.createPrettyPrint();
                XMLWriter wrt = new XMLWriter(System.out, format);
                wrt.write(doc);
                wrt.close();
            } catch (IOException e) {
                throw new Exception("XML输出至屏幕出错！");
            }
        } else {
            throw new Exception("Document 对象为空！");
        }
    }

}

XML文件增删查改操作：XmlOper.java

package org.xml;

import java.util.List;

import org.dom4j.Attribute;
import org.dom4j.Element;

public class XmlOper extends XmlBuilder {

    public XmlOper() {
        super();
    }

    public XmlOper(String path) {
        super(path);
    }

    // 根据路径查询指定XML元素
    private List<?> QueryXMLByPath(String xpath) {
        List<?> list = this.GetDoc().selectNodes(xpath);
        return list;
    }

    // 根据名称查询Root下子元素，返回第一个匹配子元素
    private Element QueryXMLByName(String name) {
        Element elem = null;
        List<?> list = QueryXMLByPath("/" + this.GetRootName() + "/*");
        int len = list.size();
        for (int i = 0; i < len; i++) {
            Element sub = (Element) list.get(i);
            if (name.equals(sub.getName())) {
                elem = sub;
                break;
            }
        }
        return elem;
    }

    // 通过属性查询指定名称元素
    public Element QueryXML(String name, String attName, String attVal) {
        List<?> list = QueryXMLByPath("/" + this.GetRootName() + "/" + name);
        int len = list.size();
        Element elem = null;
        for (int i = 0; i < len; i++) {
            Element sub = (Element) list.get(i);
            Attribute att = HasAttribute(sub, attName);
            if (att != null && attVal.equals(att.getValue())) {
                elem = sub;
                break;
            }
        }
        return elem;
    }

    // 查询XML中指定名称的第一个匹配节点
    public Element QueryXML(String name) {
        if (name == this.GetRootName()) {
            return this.GetRoot();
        }
        return QueryXMLByName(name);
    }

    // 在指定元素下添加子元素
    public Element AddElement(Element elem, String name) {
        if (elem != null) {
            elem = elem.addElement(name);
        }
        return elem;
    }

    // 判断XML父元素中是否包含指定名称的子元素
    private Element HasElement(Element parent, String name) {
        Element has = null;
        List<?> list = parent.elements();
        for (int i = 0; i < list.size(); i++) {
            Element sub = (Element) list.get(i);
            if (name.equals(sub.getName())) {
                has = sub;
                break;
            }
        }
        return has;
    }

    // 判断XML元素中是否包含指定名称的属性
    private Attribute HasAttribute(Element elem, String attName) {
        Attribute has = null;
        List<?> list = elem.attributes();
        for (int i = 0; i < list.size(); i++) {
            Attribute att = (Attribute) list.get(i);
            if (attName.equals(att.getName())) {
                has = att;
                break;
            }
        }
        return has;
    }

    // XML指定元素中删除子元素
    public boolean RemoveElement(Element parent, String name) {
        boolean succ = false;
        if (parent != null && !parent.isTextOnly()) {
            Element sub = HasElement(parent, name);
            if (sub != null) {
                succ = parent.remove(sub);
            }
        }
        return succ;
    }

    // XML指定元素下添加属性
    public Element AddAttribute(Element elem, String attName, String attVal) {
        if (elem != null) {
            elem.addAttribute(attName, attVal);
        }
        return elem;
    }

    // XML指定元素中删除指定属性
    public boolean RemoveAttribute(Element elem, String attName) {
        boolean succ = false;
        if (elem != null) {
            Attribute has = HasAttribute(elem, attName);
            if (has != null) {
                succ = elem.remove(has);
            }
        }
        return succ;
    }

    // XML指定元素下添加值
    public Element AddText(Element elem, String text) throws Exception {
        if (elem != null) {
            if (!elem.isTextOnly()) {
                throw new Exception("包含其他子元素，禁止添加文本!");
            }
            elem.addText(text);
        }
        return elem;
    }

    // XML指定元素下删除值
    public boolean RemoveText(Element elem) {
        boolean succ = false;
        if (elem != null && elem.isTextOnly()) {
            elem.setText("");
            succ = true;
        }
        return succ;
    }
}