• 使用Dom4j操作XML


    Dom4j也可以很方便完成XML文档的创建、元素的修改、文档的查询遍历等,但dom4j稍比jdom复杂一点,不过在大片文档的情况下dom4j的性能要不jdom好。

    # 准备

    首先,提供相关的jar包

    Dom4j jar包下载:

    http://sourceforge.net/projects/dom4j/files/dom4j-2.0.0-ALPHA-2/

    jaxen jar下载:

    http://repo1.maven.org/maven2/jaxen/jaxen/1.1.1/jaxen-1.1.1.jar

    和dom4j依赖或相关的jar:

    http://dom4j.sourceforge.net/dependencies.html

    Junit-jar下载:

    http://ebr.springsource.com/repository/app/bundle/version/download?name=com.springsource.org.junit&version=4.8.1&type=binary

     

    其次,准备测试案例的部分代码:

    package com.hoo.test;
     
    import java.io.File;
    import java.util.Iterator;
    import java.util.List;
    import org.dom4j.Attribute;
    import org.dom4j.Document;
    import org.dom4j.DocumentException;
    import org.dom4j.DocumentHelper;
    import org.dom4j.Element;
    import org.dom4j.Node;
    import org.dom4j.QName;
    import org.dom4j.dom.DOMAttribute;
    import org.dom4j.io.SAXReader;
    import org.dom4j.tree.BaseElement;
    import org.junit.After;
    import org.junit.Before;
    import org.junit.Test;
     
    /**
     * <b>function:</b> 使用Dom4j操作XML
     * @author hoojo
     * @createDate 2011-8-5 下午06:15:40
     * @file DocumentTest.java
     * @package com.hoo.test
     * @project Dom4jTest
     * @blog http://blog.csdn.net/IBM_hoojo
     * @email hoojo_@126.com
     * @version 1.0
     */
    public class DocumentTest {
        
        private SAXReader reader = null;
        
        @Before
        public void init() {
            reader = new SAXReader();
        }
        
        @After
        public void destory() {
            reader = null;
            System.gc();
        }
        
        public void fail(Object o) {
            if (o != null)
                System.out.println(o);
        }
    }

     

    # 创建一篇XML文档

    文档格式如下:

    <?xml version="1.0" encoding="UTF-8"?> 
    <catalog> 
        <!--An XML Catalog--> 
        <?target instruction?>
        <journal title="XML Zone" publisher="IBM developerWorks"> 
             <article level="Intermediate" date="December-2001">
                 <title>Java configuration with XML Schema</title> 
                 <author> 
                     <firstname>Marcello</firstname> 
                     <lastname>Vitaletti</lastname> 
                 </author>
               </article>
        </journal> 
    </catalog>

     

    创建文档代码如下:

    /**
     * <b>function:</b>创建文档
     * @author hoojo
     * @createDate 2011-8-5 下午06:18:18
     */
    @Test
    public void createDocument() {
        //创建一篇文档
        Document doc = DocumentHelper.createDocument();
        
        //添加一个元素
        Element root = doc.addElement("catalog");
        //为root元素添加注释
        root.addComment("An XML Catalog");
        //添加标记
        root.addProcessingInstruction("target", "instruction");
        
        //创建元素
        Element journalEl = new BaseElement("journal");
        //添加属性
        journalEl.addAttribute("title", "XML Zone");
        journalEl.addAttribute("publisher", "IBM developerWorks");
        root.add(journalEl);
        
        //添加元素
        Element articleEl = journalEl.addElement("article");
        articleEl.addAttribute("level", "Intermediate");
        articleEl.addAttribute("date", "December-2001");
        
        Element titleEl = articleEl.addElement("title");
        //设置文本内容
        titleEl.setText("Java configuration with XML Schema");
        //titleEl.addText("Java configuration with XML Schema");
        
        Element authorEl = articleEl.addElement("author");
        authorEl.addElement("firstname").setText("Marcello");
        authorEl.addElement("lastname").addText("Vitaletti");
        
        //可以使用 addDocType() 方法添加文档类型说明。 
        doc.addDocType("catalog", null,"file://c:/Dtds/catalog.dtd"); 
     
        fail(doc.getRootElement().getName());
        
        //将xml转换成文本
        fail(doc.asXML());
        
        //写入到文件
        /*XMLWriter output;
        try {
            output = new XMLWriter(new FileWriter(new File("file/catalog.xml")));
            output.write(doc);
            output.close();
        } catch (IOException e) {
            e.printStackTrace();
        }*/
    }

    * DocumentHelper是一个文档助手类(工具类),它可以完成文档、元素、文本、属性、注释、CDATA、Namespace、XPath的创建,以及利用XPath完成文档的遍历和将文本转换成Document;

    parseText完成将xml字符串转换成Doc的功能

    Document doc = DocumentHelper.parseText("<root></root>");

    createDocument创建一个文档

    Document doc = DocumentHelper.createDocument();

    如果带参数就会创建一个带有根元素的文档

     

    createElement创建一个元素

    Element el = DocumentHelper.createElement("el");

    * Document的addElement方法可以给当前文档添加一个子元素

    Element root = doc.addElement("catalog");

    * addComment方法可以添加一段注释

    root.addComment("An XML Catalog");

    为root元素添加一段注释

     

    * addProcessingInstruction添加一个标记

    root.addProcessingInstruction("target", "instruction");

    为root元素添加一个标记

     

    * new BaseElement可以创建一个元素

    Element journalEl = new BaseElement("journal");

     

    * addAttribute添加属性

    journalEl.addAttribute("title", "XML Zone");

    * add添加一个元素

    root.add(journalEl);

    将journalEl元素添加到root元素中

     

    * addElement添加一个元素,并返回当前元素

    Element articleEl = journalEl.addElement("article");

    给journalEl元素添加一个子元素article

     

    * setText、addText可以设置元素的文本

    authorEl.addElement("firstname").setText("Marcello");
    authorEl.addElement("lastname").addText("Vitaletti");

    * addDocType可以设置文档的DOCTYPE

    doc.addDocType("catalog", null,file://c:/Dtds/catalog.dtd);

    * asXML可以将文档或元素转换成一段xml字符串

    doc.asXML();
    root.asXML();

    * XMLWriter类可以把文档写入到文件中

    output = new XMLWriter(new FileWriter(new File("file/catalog.xml")));
    output.write(doc);
    output.close();

     

    # 修改XML文档内容

    /**
     * <b>function:</b> 修改XML内容
     * @author hoojo
     * @createDate 2011-8-9 下午03:37:04
     */
    @SuppressWarnings("unchecked")
    @Test
    public void modifyDoc() {
        try {
            Document doc = reader.read(new File("file/catalog.xml"));
            
            //修改属性内容
            List list = doc.selectNodes("//article/@level");
            Iterator<Attribute> iter = list.iterator();
            while (iter.hasNext()) {
                Attribute attr = iter.next();
                fail(attr.getName() + "#" + attr.getValue() + "#" + attr.getText());
                if ("Intermediate".equals(attr.getValue())) {
                    //修改属性值
                    attr.setValue("Introductory");
                    fail(attr.getName() + "#" + attr.getValue() + "#" + attr.getText());
                }
            }
            
            list = doc.selectNodes("//article/@date");
            iter = list.iterator();
            while (iter.hasNext()) {
                Attribute attr = iter.next();
                fail(attr.getName() + "#" + attr.getValue() + "#" + attr.getText());
                if ("December-2001".equals(attr.getValue())) {
                    //修改属性值
                    attr.setValue("December-2011");
                    fail(attr.getName() + "#" + attr.getValue() + "#" + attr.getText());
                }
            }
            
            //修改节点内容
            list = doc.selectNodes("//article");
            Iterator<Element> it = list.iterator();
            while (it.hasNext()) {
                Element el = it.next();
                fail(el.getName() + "#" + el.getText() + "#" + el.getStringValue());
                //修改title元素
                Iterator<Element> elIter = el.elementIterator("title");
                while(elIter.hasNext()) {
                    Element titleEl = elIter.next();
                    fail(titleEl.getName() + "#" + titleEl.getText() + "#" + titleEl.getStringValue());
                    if ("Java configuration with XML Schema".equals(titleEl.getTextTrim())) {
                        //修改元素文本值
                        titleEl.setText("Modify the Java configuration with XML Schema");
                        fail(titleEl.getName() + "#" + titleEl.getText() + "#" + titleEl.getStringValue());
                    }
                }
            }
            
            //修改节点子元素内容
            list = doc.selectNodes("//article/author");
            it = list.iterator();
            while (it.hasNext()) {
                Element el = it.next();
                fail(el.getName() + "#" + el.getText() + "#" + el.getStringValue());
                List<Element> childs = el.elements();
                for (Element e : childs) {
                    fail(e.getName() + "#" + e.getText() + "#" + e.getStringValue());
                    if ("Marcello".equals(e.getTextTrim())) {
                        e.setText("Ayesha");
                    } else if ("Vitaletti".equals(e.getTextTrim())) {
                        e.setText("Malik");
                    } 
                    fail(e.getName() + "#" + e.getText() + "#" + e.getStringValue());
                }
            }
            
            //写入到文件
            /*XMLWriter output = new XMLWriter(new FileWriter(new File("file/catalog-modified.xml")));
            output.write(doc);
            output.close();*/
        } catch (DocumentException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    * reader.read(new File("file/catalog.xml"));读取指定xml文件内容到文档中;

    * selectNodes是XPath的查询方法,完成xml文档的查询,传递xpath路径。其使用方法可以参考jdom的xpath的使用方法:

         http://www.cnblogs.com/hoojo/archive/2011/08/11/2134638.html

    * getName获取元素标签名称、getValue、getText获取值、文本内容;

    * elementIterator("title");获取当前节点下所有的title元素,返回Iterator;

    * elements获取下面所有的子元素,返回的是一个集合List;

     

    # 显示文档相关信息

    private String format(int i) {
        String temp = "";
        while (i > 0) {
            temp += "--";
            i--;
        }
        return temp;
    }
     
    /**
     * <b>function:</b>递归显示文档内容
     * @author hoojo
     * @createDate 2011-8-9 下午03:43:45
     * @param i
     * @param els
     */
    private void print(int i, List<Element> els) {
        i++;
        for (Element el : els) {
            fail(format(i) + "##" + el.getName() + "#" + el.getTextTrim());
            if (el.hasContent()) {
                print(i, el.elements());
            } 
        }
    }
     
    /**
     * <b>function:</b>显示文档相关信息
     * @author hoojo
     * @createDate 2011-8-9 下午03:44:10
     */
    @Test
    public void printInfo() {
        try {
            Document doc = reader.read(new File("file/catalog.xml"));
            fail("asXML: " + doc.asXML());
            
            fail(doc.asXPathResult(new BaseElement("article")));
            List<Node> list = doc.content();
            for (Node node : list) {
                fail("Node: " + node.getName() + "#" + node.getText() + "#" + node.getStringValue());
            }
            
            fail("-----------------------------");
            print(0, doc.getRootElement().elements());
            
            fail("getDocType: " + doc.getDocType());
            fail("getNodeTypeName: " + doc.getNodeTypeName());
            fail("getPath: " + doc.getRootElement().getPath());
            fail("getPath: " + doc.getRootElement().getPath(new BaseElement("journal")));
            fail("getUniquePath: " + doc.getRootElement().getUniquePath());
            fail("getXMLEncoding: " + doc.getXMLEncoding());
            fail("hasContent: " + doc.hasContent());
            fail("isReadOnly: " + doc.isReadOnly());
            fail("nodeCount: " + doc.nodeCount());
            fail("supportsParent: " + doc.supportsParent());
        } catch (DocumentException e) {
            e.printStackTrace();
        }
        fail("getEncoding: " + reader.getEncoding());
        fail("isIgnoreComments: " + reader.isIgnoreComments());
        fail("isMergeAdjacentText: " + reader.isMergeAdjacentText());
        fail("isStringInternEnabled: " + reader.isStringInternEnabled());
        fail("isStripWhitespaceText: " + reader.isStripWhitespaceText());
        fail("isValidating: " + reader.isValidating());
    }

     

    # 删除文档内容

    /**
     * <b>function:</b> 删除节点内容
     * @author hoojo
     * @createDate 2011-8-9 下午03:47:44
     */
    @Test
    public void removeNode() {
        try {
            Document doc = reader.read(new File("file/catalog-modified.xml"));
            fail("comment: " + doc.selectSingleNode("//comment()"));
            //删除注释
            doc.getRootElement().remove(doc.selectSingleNode("//comment()"));
            
            Element node = (Element) doc.selectSingleNode("//article");
            //删除属性
            node.remove(new DOMAttribute(QName.get("level"), "Introductory"));
            //删除元素 节点
            node.remove(doc.selectSingleNode("//title"));
            
            //只能删除下一级节点,不能超过一级;(需要在父元素的节点上删除子元素)
            Node lastNameNode = node.selectSingleNode("//lastname");
            lastNameNode.getParent().remove(lastNameNode);
            
            fail("Text: " + doc.selectObject("//*[text()='Ayesha']"));
            Element firstNameEl = (Element)doc.selectObject("//firstname");
            fail("Text: " + firstNameEl.selectSingleNode("text()"));
            
            //删除text文本
            //firstNameEl.remove(firstNameEl.selectSingleNode("text()"));
            //firstNameEl.remove(doc.selectSingleNode("//firstname/text()"));
            firstNameEl.remove(doc.selectSingleNode("//*[text()='Ayesha']/text()"));
            
            //删除子元素author
            //node.remove(node.selectSingleNode("//author"));
            
            fail(doc.asXML());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

     

    * 删除注释

    doc.getRootElement().remove(doc.selectSingleNode("//comment()"));

    删除root元素下面的注释

     

    * 删除属性

    node.remove(new DOMAttribute(QName.get("level"), "Introductory"));

    删除node节点中的名称为level,其值为Introductory的属性

     

    * 删除元素

    node.remove(doc.selectSingleNode("//title"));

    删除node节点下的title元素

     

    * 删除文本

    firstNameEl.remove(firstNameEl.selectSingleNode("text()"));
    firstNameEl.remove(doc.selectSingleNode("//firstname/text()"));
    firstNameEl.remove(doc.selectSingleNode("//*[text()='Ayesha']/text()"));

    删除firstNameEl的文本内容

  • 作者:hoojo
    出处:
    blog:http://blog.csdn.net/IBM_hoojo
    本文版权归作者和博客园共有,欢迎转载,但未经作者同意必须保留此段声明,且在文章页面明显位置给出原文连接,否则保留追究法律责任的权利。

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  • 原文地址:https://www.cnblogs.com/hoojo/p/2135743.html
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