java中的xml操作

（1）使用java读取XML文件： DOM解析XML

XML样例如下：（language.xml）

<?xmlversion="1.0"encoding="UTF-8"?>

<Languagescat="it">

  <lanid="1">

     <name>java</name>

     <ide>eclipse</ide>

  </lan>

  <lanid="2">

     <name>swift</name>

     <ide>Xcode</ide>

  </lan>

  <lanid="3">

     <name>C#</name>

     <ide>Visual Studio</ide>

  </lan>

</Languages>

解析方式如下：

//DOM解析XML（用try catch）

DocumentBuilderFactoryfactory = DocumentBuilderFactory.newInstance();

                DocumentBuilder builder =factory.newDocumentBuilder();

                Document doc =builder.parse("language.xml");

                Elementroot = (Element)doc.getDocumentElement();

                System.out.println("cat = "+root.getAttribute("cat"));

                NodeList list =root.getElementsByTagName("lan");

                for  (inti =0;i<list.getLength();i++)

                {

                   Elementlan = (Element)list.item(i);

                   System.out.println("-----------------");

                   System.out.println("id="+lan.getAttribute("id"));·

//  Element name = (Element)lan.getElementsByTagName("name").item(0);

//                 System.out.println(name.getTextContent());

//  Element ide = (Element)lan.getElementsByTagName("ide").item(0);

//                 System.out.println(ide.getTextContent());

                   NodeList cList =lan.getChildNodes();

                    for(intj = 0;j<=cList.getLength();j++){

                       Node e =cList.item(j);

                       if(einstanceof Element) {

                System.out.println(e.getNodeName()+"="+e.getTextContent());

                       }

                   }

                }

运行结果：

cat = it

-----------------

id=1

name=java

ide=eclipse

-----------------

id=2

name=swift

ide=Xcode

-----------------

id=3

name=C#

ide=Visual Studio

 

（2）使用java创建XML数据：

 

public static void main(String[] args) {

          try {

            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();

            DocumentBuilder builder =factory.newDocumentBuilder();

            Document document =builder.newDocument();

           

            Element root = document.createElement("language");

            root.setAttribute("cat","it");

           

            Element lan1 = document.createElement("lan");

            lan1.setAttribute("id","1");

            Element name1 = document.createElement("name");

            name1.setTextContent("java");

            Element ide1 = document.createElement("ide");

            ide1.setTextContent("eclipse");

           

           

            Element lan2 = document.createElement("lan");

            lan2.setAttribute("id","2");

            Element name2 = document.createElement("name");

            name2.setTextContent("swift");

            Element ide2 = document.createElement("ide");

            ide2.setTextContent("Xcode");

           

            Element lan3 = document.createElement("lan");

            lan3.setAttribute("id","3");

            Element name3 = document.createElement("name");

            name3.setTextContent("C#");

            Element ide3 = document.createElement("ide");

            ide3.setTextContent("visualStudio");

           

            lan1.appendChild(name1);

            lan1.appendChild(ide1);

            root.appendChild(lan1);

           

            lan2.appendChild(name2);

            lan2.appendChild(ide2);

            root.appendChild(lan2);

           

           

            lan3.appendChild(name3);

            lan3.appendChild(ide3);

            root.appendChild(lan3);

           

            document.appendChild(root) ;          

            //---------将当前文档转化成字符串显示----------------------

            try {

               

                TransformerFactory transformerFactory =TransformerFactory.newInstance();

                Transformer transformer =transformerFactory.newTransformer();

                StringWriter writer =new StringWriter();

                //转化输入输出流

                transformer.transform(new DOMSource(document),new StreamResult(writer));

                System.out.println(writer.toString());

                //文件

                transformer.transform(new DOMSource(document),new StreamResult(new File("111.xml")));

               

            } catch (TransformerConfigurationExceptione) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            } catch (TransformerExceptione) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            }

        } catch (ParserConfigurationExceptione) {

            e.printStackTrace();

        }

    }

 

运行后，刷新项目（F5）就会发现项目中创建了111.xml文件，在控制台也有输出。创建好的文件没有格式，全选内容，用ctrl+I快捷键格式化数据，就可以看到有层次感的xml文件。

如下所示：

<?xmlversion="1.0"encoding="UTF-8"standalone="no"?>

<languagecat="it">

    <lanid="1">

        <name>java</name>

        <ide>eclipse</ide>

    </lan>

    <lanid="2">

        <name>swift</name>

        <ide>Xcode</ide>

    </lan>

    <lanid="3">

        <name>C#</name>

        <ide>visualStudio</ide>

    </lan>

</language>

 

 

（3）使用DOM4J操作xml数据:

工具下载网址：www.dom4j.org/dom4j-1.6.1/

在项目中新建一个lib文件夹。将dom4j下载并解压，解压后的dom4j-1.6.jar拷贝在工程目录Lib文件夹下。在main()中：

String xmlString = “ <lan><name>java</name><ide>eclipse</ide></lan>”

 Document doc=DocumentHelper.pareseText(xmlString);

System.out.println(document.asXML));

若需要了解其他的用法，打开解压后的/doc/index就可以查看完整的操作说明。