java解析XML几种方式小结

java解析XML几种方式小结

第一种:DOM。

DOM的全称是Document Object Model,也即文档对象模型。在应用程序中,基于DOM的XML分析器将一个XML文档转换成一个对象模型的集合(通常称DOM树),应用程序正是通过对这个对象模型的操作,来实现对XML文档数据的操作。通过DOM接口,应用程序可以在任何时候访问XML文档中的任何一部分数据,因此,这种利用DOM接口的机制也被称作随机访问机制。

DOM接口提供了一种通过分层对象模型来访问XML文档信息的方式,这些分层对象模型依据XML的文档结构形成了一棵节点树。无论XML文档中所描述的是什么类型的信息,即便是制表数据、项目列表或一个文档,利用DOM所生成的模型都是节点树的形式。也就是说,DOM强制使用树模型来访问XML文档中的信息。由于XML本质上就是一种分层结构,所以这种描述方法是相当有效的。

DOM树所提供的随机访问方式给应用程序的开发带来了很大的灵活性,它可以任意地控制整个XML文档中的内容。然而,由于DOM分析器把整个XML文档转化成DOM树放在了内存中,因此,当文档比较大或者结构比较复杂时,对内存的需求就比较高。而且,对于结构复杂的树的遍历也是一项耗时的操作。所以,DOM分析器对机器性能的要求比较高,实现效率不十分理想。不过,由于DOM分析器所采用的树结构的思想与XML文档的结构相吻合,同时鉴于随机访问所带来的方便,因此,DOM分析器还是有很广泛的使用价值的。

import java.io.File; 
 
import javax.xml.parsers.DocumentBuilder; 
import javax.xml.parsers.DocumentBuilderFactory; 
 
import org.w3c.dom.Document; 
import org.w3c.dom.Element; 
import org.w3c.dom.NodeList; 
 
public class DomTest1 
{ 
  public static void main(String[] args) throws Exception 
  { 
    // step 1: 获得dom解析器工厂(工作的作用是用于创建具体的解析器) 
    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); 
     
//   System.out.println("class name: " + dbf.getClass().getName()); 
     
    // step 2:获得具体的dom解析器 
    DocumentBuilder db = dbf.newDocumentBuilder(); 
     
//   System.out.println("class name: " + db.getClass().getName()); 
     
    // step3: 解析一个xml文档,获得Document对象(根结点) 
    Document document = db.parse(new File("candidate.xml")); 
     
    NodeList list = document.getElementsByTagName("PERSON"); 
     
    for(int i = 0; i < list.getLength(); i++) 
    { 
      Element element = (Element)list.item(i); 
       
      String content = element.getElementsByTagName("NAME").item(0).getFirstChild().getNodeValue(); 
       
      System.out.println("name:" + content); 
       
      content = element.getElementsByTagName("ADDRESS").item(0).getFirstChild().getNodeValue(); 
       
      System.out.println("address:" + content); 
       
      content = element.getElementsByTagName("TEL").item(0).getFirstChild().getNodeValue(); 
       
      System.out.println("tel:" + content); 
       
      content = element.getElementsByTagName("FAX").item(0).getFirstChild().getNodeValue(); 
       
      System.out.println("fax:" + content); 
       
      content = element.getElementsByTagName("EMAIL").item(0).getFirstChild().getNodeValue(); 
       
      System.out.println("email:" + content); 
       
      System.out.println("--------------------------------------"); 
    } 
  } 
} 
 

import java.io.File; 
 
import javax.xml.parsers.DocumentBuilder; 
import javax.xml.parsers.DocumentBuilderFactory; 
 
import org.w3c.dom.Attr; 
import org.w3c.dom.Comment; 
import org.w3c.dom.Document; 
import org.w3c.dom.Element; 
import org.w3c.dom.NamedNodeMap; 
import org.w3c.dom.Node; 
import org.w3c.dom.NodeList; 
 
/** 
 * 使用递归解析给定的任意一个xml文档并且将其内容输出到命令行上 
 * @author zhanglong 
 * 
 */ 
public class DomTest3 
{ 
  public static void main(String[] args) throws Exception 
  { 
    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); 
    DocumentBuilder db = dbf.newDocumentBuilder(); 
     
    Document doc = db.parse(new File("student.xml")); 
    //获得根元素结点 
    Element root = doc.getDocumentElement(); 
     
    parseElement(root); 
  } 
   
  private static void parseElement(Element element) 
  { 
    String tagName = element.getNodeName(); 
     
    NodeList children = element.getChildNodes(); 
     
    System.out.print("<" + tagName); 
     
    //element元素的所有属性所构成的NamedNodeMap对象,需要对其进行判断 
    NamedNodeMap map = element.getAttributes(); 
     
    //如果该元素存在属性 
    if(null != map) 
    { 
      for(int i = 0; i < map.getLength(); i++) 
      { 
        //获得该元素的每一个属性 
        Attr attr = (Attr)map.item(i); 
         
        String attrName = attr.getName(); 
        String attrValue = attr.getValue(); 
         
        System.out.print(" " + attrName + "=\"" + attrValue + "\""); 
      } 
    } 
     
    System.out.print(">"); 
     
    for(int i = 0; i < children.getLength(); i++) 
    { 
      Node node = children.item(i); 
      //获得结点的类型 
      short nodeType = node.getNodeType(); 
       
      if(nodeType == Node.ELEMENT_NODE) 
      { 
        //是元素,继续递归 
        parseElement((Element)node); 
      } 
      else if(nodeType == Node.TEXT_NODE) 
      { 
        //递归出口 
        System.out.print(node.getNodeValue()); 
      } 
      else if(nodeType == Node.COMMENT_NODE) 
      { 
        System.out.print("<!--"); 
         
        Comment comment = (Comment)node; 
         
        //注释内容 
        String data = comment.getData(); 
         
        System.out.print(data); 
         
        System.out.print("-->"); 
      } 
    } 
     
    System.out.print("</" + tagName + ">"); 
  } 
} 

sax:SAX的全称是Simple APIs for XML,也即XML简单应用程序接口。与DOM不同,SAX提供的访问模式是一种顺序模式,这是一种快速读写XML数据的方式。当使用SAX分析器对XML文档进行分析时,会触发一系列事件,并激活相应的事件处理函数,应用程序通过这些事件处理函数实现对XML文档的访问,因而SAX接口也被称作事件驱动接口。

import java.io.File; 
 
import javax.xml.parsers.SAXParser; 
import javax.xml.parsers.SAXParserFactory; 
 
import org.xml.sax.Attributes; 
import org.xml.sax.SAXException; 
import org.xml.sax.helpers.DefaultHandler; 
 
public class SaxTest1 
{ 
  public static void main(String[] args) throws Exception 
  { 
    //step1: 获得SAX解析器工厂实例 
    SAXParserFactory factory = SAXParserFactory.newInstance(); 
     
    //step2: 获得SAX解析器实例 
    SAXParser parser = factory.newSAXParser(); 
     
    //step3: 开始进行解析 
    parser.parse(new File("student.xml"), new MyHandler()); 
     
  } 
} 
 
class MyHandler extends DefaultHandler 
{ 
  @Override 
  public void startDocument() throws SAXException 
  { 
    System.out.println("parse began"); 
  } 
   
  @Override 
  public void endDocument() throws SAXException 
  { 
    System.out.println("parse finished"); 
  } 
   
  @Override 
  public void startElement(String uri, String localName, String qName, 
      Attributes attributes) throws SAXException 
  { 
    System.out.println("start element"); 
  } 
   
  @Override 
  public void endElement(String uri, String localName, String qName) 
      throws SAXException 
  { 
    System.out.println("finish element"); 
  } 
} 

import java.io.File; 
import java.util.Stack; 
 
import javax.xml.parsers.SAXParser; 
import javax.xml.parsers.SAXParserFactory; 
 
import org.xml.sax.Attributes; 
import org.xml.sax.SAXException; 
import org.xml.sax.helpers.DefaultHandler; 
 
public class SaxTest2 
{ 
  public static void main(String[] args) throws Exception 
  { 
    SAXParserFactory factory = SAXParserFactory.newInstance(); 
     
    SAXParser parser = factory.newSAXParser(); 
     
    parser.parse(new File("student.xml"), new MyHandler2()); 
  } 
} 
 
class MyHandler2 extends DefaultHandler 
{ 
  private Stack<String> stack = new Stack<String>(); 
   
  private String name; 
   
  private String gender; 
   
  private String age; 
   
  @Override 
  public void startElement(String uri, String localName, String qName, 
      Attributes attributes) throws SAXException 
  { 
    stack.push(qName); 
     
    for(int i = 0; i < attributes.getLength(); i++) 
    { 
      String attrName = attributes.getQName(i); 
      String attrValue = attributes.getValue(i); 
       
      System.out.println(attrName + "=" + attrValue); 
    } 
  } 
   
  @Override 
  public void characters(char[] ch, int start, int length) 
      throws SAXException 
  { 
    String tag = stack.peek(); 
     
    if("姓名".equals(tag)) 
    { 
      name = new String(ch, start,length); 
    } 
    else if("性别".equals(tag)) 
    { 
      gender = new String(ch, start, length); 
    } 
    else if("年龄".equals(tag)) 
    { 
      age = new String(ch, start, length); 
    } 
  } 
   
  @Override 
  public void endElement(String uri, String localName, String qName) 
      throws SAXException 
  { 
    stack.pop(); //表示该元素已经解析完毕,需要从栈中弹出 
     
    if("学生".equals(qName)) 
    { 
      System.out.println("姓名:" + name); 
      System.out.println("性别:" + gender); 
      System.out.println("年龄:" + age); 
       
      System.out.println(); 
    } 
     
  } 
} 


JDOM:

JDOM是一个开源项目,它基于树型结构,利用纯JAVA的技术对XML文档实现解析、生成、序列化以及多种操作。(http://jdom.org

•JDOM 直接为JAVA编程服务。它利用更为强有力的JAVA语言的诸多特性(方法重载、集合概念等),把SAX和DOM的功能有效地结合起来。

•JDOM是用Java语言读、写、操作XML的新API函数。在直接、简单和高效的前提下,这些API函数被最大限度的优化。

jdom创建xml

import java.io.FileWriter; 
 
import org.jdom.Attribute; 
import org.jdom.Comment; 
import org.jdom.Document; 
import org.jdom.Element; 
import org.jdom.output.Format; 
import org.jdom.output.XMLOutputter; 
 
public class JDomTest1 
{ 
  public static void main(String[] args) throws Exception 
  { 
    Document document = new Document(); 
 
    Element root = new Element("root"); 
 
    document.addContent(root); 
 
    Comment comment = new Comment("This is my comments"); 
 
    root.addContent(comment); 
 
    Element e = new Element("hello"); 
 
    e.setAttribute("sohu", "www.sohu.com"); 
 
    root.addContent(e); 
 
    Element e2 = new Element("world"); 
 
    Attribute attr = new Attribute("test", "hehe"); 
 
    e2.setAttribute(attr); 
 
    e.addContent(e2); 
 
    e2.addContent(new Element("aaa").setAttribute("a", "b") 
        .setAttribute("x", "y").setAttribute("gg", "hh").setText("text content")); 
 
     
    Format format = Format.getPrettyFormat(); 
     
    format.setIndent("  "); 
//   format.setEncoding("gbk"); 
     
    XMLOutputter out = new XMLOutputter(format); 
 
    out.output(document, new FileWriter("jdom.xml")); 
     
  } 
} 

JDOM解析xml

import java.io.File; 
import java.io.FileOutputStream; 
import java.util.List; 
 
import org.jdom.Attribute; 
import org.jdom.Document; 
import org.jdom.Element; 
import org.jdom.input.SAXBuilder; 
import org.jdom.output.Format; 
import org.jdom.output.XMLOutputter; 
 
public class JDomTest2 
{ 
  public static void main(String[] args) throws Exception 
  { 
    SAXBuilder builder = new SAXBuilder(); 
     
    Document doc = builder.build(new File("jdom.xml")); 
     
    Element element = doc.getRootElement(); 
     
    System.out.println(element.getName()); 
     
    Element hello = element.getChild("hello"); 
     
    System.out.println(hello.getText()); 
     
    List list = hello.getAttributes(); 
     
    for(int i = 0 ;i < list.size(); i++) 
    { 
      Attribute attr = (Attribute)list.get(i); 
       
      String attrName = attr.getName(); 
      String attrValue = attr.getValue(); 
       
      System.out.println(attrName + "=" + attrValue); 
    } 
     
    hello.removeChild("world"); 
     
    XMLOutputter out = new XMLOutputter(Format.getPrettyFormat().setIndent("  ")); 
     
     
    out.output(doc, new FileOutputStream("jdom2.xml"));    
     
  } 
} 

Dom4j

import java.io.FileOutputStream; 
import java.io.FileWriter; 
 
import org.dom4j.Document; 
import org.dom4j.DocumentHelper; 
import org.dom4j.Element; 
import org.dom4j.io.OutputFormat; 
import org.dom4j.io.XMLWriter; 
 
public class Test1 
{ 
  public static void main(String[] args) throws Exception 
  { 
    // 创建文档并设置文档的根元素节点 :第一种方式 
    // Document document = DocumentHelper.createDocument(); 
    // 
    // Element root = DocumentHelper.createElement("student"); 
    // 
    // document.setRootElement(root); 
 
    // 创建文档并设置文档的根元素节点 :第二种方式 
    Element root = DocumentHelper.createElement("student"); 
    Document document = DocumentHelper.createDocument(root); 
 
    root.addAttribute("name", "zhangsan"); 
 
    Element helloElement = root.addElement("hello"); 
    Element worldElement = root.addElement("world"); 
 
    helloElement.setText("hello"); 
    worldElement.setText("world"); 
 
    helloElement.addAttribute("age", "20"); 
 
    XMLWriter xmlWriter = new XMLWriter(); 
    xmlWriter.write(document); 
     
    OutputFormat format = new OutputFormat("  ", true); 
     
    XMLWriter xmlWriter2 = new XMLWriter(new FileOutputStream("student2.xml"), format); 
    xmlWriter2.write(document); 
     
    XMLWriter xmlWriter3 = new XMLWriter(new FileWriter("student3.xml"), format); 
     
    xmlWriter3.write(document); 
    xmlWriter3.close(); 
 
  } 
} 
 

import java.io.File; 
import java.util.Iterator; 
import java.util.List; 
 
import javax.xml.parsers.DocumentBuilder; 
import javax.xml.parsers.DocumentBuilderFactory; 
 
import org.dom4j.Document; 
import org.dom4j.Element; 
import org.dom4j.io.DOMReader; 
import org.dom4j.io.SAXReader; 
 
public class Test2 
{ 
  public static void main(String[] args) throws Exception 
  { 
    SAXReader saxReader = new SAXReader(); 
     
    Document doc = saxReader.read(new File("student2.xml")); 
     
    Element root = doc.getRootElement(); 
     
    System.out.println("root element: " + root.getName()); 
     
    List childList = root.elements(); 
     
    System.out.println(childList.size()); 
     
    List childList2 = root.elements("hello"); 
     
    System.out.println(childList2.size()); 
     
    Element first = root.element("hello"); 
     
    System.out.println(first.attributeValue("age")); 
     
    for(Iterator iter = root.elementIterator(); iter.hasNext();) 
    { 
      Element e = (Element)iter.next(); 
       
      System.out.println(e.attributeValue("age")); 
    } 
     
    System.out.println("---------------------------"); 
     
    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); 
    DocumentBuilder db = dbf.newDocumentBuilder(); 
    org.w3c.dom.Document document = db.parse(new File("student2.xml")); 
     
    DOMReader domReader = new DOMReader(); 
     
    //将JAXP的Document转换为dom4j的Document 
    Document d = domReader.read(document); 
     
    Element rootElement = d.getRootElement(); 
     
    System.out.println(rootElement.getName()); 
 
  } 
} 
 

import java.io.FileWriter; 
 
import org.jdom.Attribute; 
import org.jdom.Document; 
import org.jdom.Element; 
import org.jdom.output.Format; 
import org.jdom.output.XMLOutputter; 
 
public class Test3 
{ 
  public static void main(String[] args) throws Exception 
  { 
    Document document = new Document(); 
 
    Element root = new Element("联系人列表").setAttribute(new Attribute("公司", 
        "A集团")); 
 
    document.addContent(root); 
     
    Element contactPerson = new Element("联系人"); 
     
    root.addContent(contactPerson); 
 
    contactPerson 
        .addContent(new Element("姓名").setText("张三")) 
        .addContent(new Element("公司").setText("A公司")) 
        .addContent(new Element("电话").setText("021-55556666")) 
        .addContent( 
            new Element("地址") 
                .addContent(new Element("街道").setText("5街")) 
                .addContent(new Element("城市").setText("上海")) 
                .addContent(new Element("省份").setText("上海市"))); 
 
    XMLOutputter output = new XMLOutputter(Format.getPrettyFormat() 
        .setIndent("  ").setEncoding("gbk")); 
 
    output.output(document, new FileWriter("contact.xml")); 
 
  } 
}