Java解析XML三种常用方法

 1 package com.wzh.dom;
 3 import java.util.Iterator;
 5 import javax.xml.parsers.DocumentBuilder;
 6 import javax.xml.parsers.DocumentBuilderFactory;
 8 import org.w3c.dom.Document;
 9 import org.w3c.dom.Element;
10 import org.w3c.dom.NamedNodeMap;
11 import org.w3c.dom.Node;
12 import org.w3c.dom.NodeList;
14 public class DomHandler {
15  
16     /*
17      * 解析XML
18      */
19     public void read(String fileName) throws Exception {
20         // 定义工厂API 使应用程序能够从XML文档获取生成DOM对象树的解析器
21         DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
22         // 获取此类的实例之后，将可以从各种输入源解析XML
23         DocumentBuilder builder = factory.newDocumentBuilder();
24         // builder.parse(this.getClass().getResourceAsStream("/" + fileName));
25         // Document接口表示整个HTML或XML文档，从概念上讲，它是文档树的根，并提供对文档数据的基本访问
26         Document document = builder.parse(this.getClass().getResourceAsStream(
27                 "/" + fileName));
28         // 获取根节点
29         Element root = document.getDocumentElement();
30         System.out.println(root.getNodeName());
31  
32         //读取database节点NodeList接口提供对节点的有序集合的抽象
33         NodeList nodeList = root.getElementsByTagName("database");
34         for (int i = 0; i < nodeList.getLength(); i++) {
35             // 获取一个节点
36             Node node = nodeList.item(i);
37             // 获取该节点所有属性
38             NamedNodeMap attributes = node.getAttributes();
39             for (int j = 0; j < attributes.getLength(); j++) {
40                 Node attribute = attributes.item(j);
41                 System.out.println(attribute.getNodeName() + ":"
42                         + attribute.getNodeValue());
43             }
44             //获取所有子节点数据
45             NodeList childNodes=node.getChildNodes();
46             for (int j = 0; j < childNodes.getLength(); j++) {
47                 Node childNode=childNodes.item(j);
48                 System.out.println(childNode.getNodeName()+":"+childNode.getNodeValue());
49             }
50         }
51     }
52  
53     public static void main(String[] args) throws Exception {
54         new DomHandler().read("data-source.xml");
55  
56     }
57 }

 1 package com.wzh.sax; 
 3 import org.xml.sax.Attributes;
 4 import org.xml.sax.SAXException;
 5 import org.xml.sax.helpers.DefaultHandler;
 7 //
 8 public class Saxhandler extends DefaultHandler {
 9  
10     @Override
11     public void startDocument() throws SAXException {
12         System.out.println("开始解析XML文档...");
13     }
14  
15     @Override
16     public void endDocument() throws SAXException {
17         System.out.println("结束解析XML文档...");
18     }
19  
20     @Override
21     public void startElement(String uri, String localName, String qName,
22             Attributes attributes) throws SAXException {
23         // TODO Auto-generated method stub
24         super.startElement(uri, localName, qName, attributes);
25         System.out.println("开始解析节点["+qName+"]...");
26         System.out.println("共有["+attributes.getLength()+"]个属性");
27     }
28  
29     @Override
30     public void characters(char[] ch, int start, int length)
31             throws SAXException {
32         // TODO Auto-generated method stub
33         super.characters(ch, start, length);
34         String content =new String(ch,start,length);
35         System.out.println(content);
36     }
37  
38     @Override
39     public void endElement(String uri, String localName, String qName)
40             throws SAXException {
41         // TODO Auto-generated method stub
42         super.endElement(uri, localName, qName);
43         System.out.println("结束解析XML节点...");
44     }
45 }

  1 package com.wzh.dom4j;
  3 import java.io.FileOutputStream;
  4 import java.sql.DatabaseMetaData;
  5 import java.util.Iterator;
  6 import java.util.List;
  8 import org.dom4j.*;
  9 import org.dom4j.io.OutputFormat;
 10 import org.dom4j.io.SAXReader;
 11 import org.dom4j.io.XMLWriter;
 12
 13 public class Dom4jHandler {
 15 public void add() throws Exception {
 16 // 1.创建一个Document
 17 Document document = DocumentHelper.createDocument();
 18 // 2.给Document添加数据
 19 Element root = document.addElement("DataSource");
 20 // 添加注释
 21 root.addComment("这是注释信息");
 22 // 在root根节点下面添加一个子节点
 23 Element database = root.addElement("database");
 24 database.addAttribute("name", "mysql");
 25 database.addAttribute("version", "5.0");
 26 // 添加子节点
 27 database.addElement("driver").setText("com.mysql.jdbc.Driver");
 28 database.addElement("url")
 29 .setText("jdbc:mysql://localhost:3306/myjdbc");
 30 database.addElement("user").setText("root");
 31 database.addElement("password").setText("root");
 32 // 3.将Document写出文件
 33 OutputFormat format = OutputFormat.createPrettyPrint();
 34 format.setEncoding("utf-8");
 35 // FileOutputStream默认生成的路径在根路径
 36 XMLWriter xw = new XMLWriter(new FileOutputStream("db.xml"), format);
 37 xw.write(document);
 38 xw.close();
 39 }
 40 
 41 public void update(String fileName) throws Exception {
 42 // sax解析器
 43 SAXReader saxReader = new SAXReader();
 44 // 读到对象
 45 Document document = saxReader.read(this.getClass().getResourceAsStream(
 46 "/" + fileName));
 47 Element root = document.getRootElement();
 48 List<Element> databases_node = root.elements("database");
 49 for (Element database_node : databases_node) {
 50 if (database_node.attributeValue("name").equalsIgnoreCase("mysql")) {
 51 System.out.println("old:"
 52 + database_node.attributeValue("name"));
 53 database_node.attribute("name").setText("Oracle");
 54 System.out.println("update:"
 55 + database_node.attributeValue("name"));
 56 
 57 database_node.element("driver").setText("oracel");
 58 database_node.element("url").setText("jdbc");
 59 
 60 // 删除password节点
 61 database_node.remove(database_node.element("password"));
 62 
 63 // 删除属性
 64 database_node.remove(database_node.attribute("version"));
 65 }
 66 }
 67 
 68 OutputFormat format = OutputFormat.createPrettyPrint();
 69 format.setEncoding("utf-8");
 70 // FileOutputStream默认生成的路径在根路径
 71 XMLWriter xw = new XMLWriter(new FileOutputStream("db2.xml"), format);
 72 xw.write(document);
 73 xw.close();
 74 }
 75 
 76 public void read(String fileName) throws Exception {
 77 // sax解析器
 78 SAXReader saxReader = new SAXReader();
 79 // 读到对象
 80 Document document = saxReader.read(this.getClass().getResourceAsStream(
 81 "/" + fileName));
 82 Element root = document.getRootElement();
 83 System.out.println("根节点：" + root.getName());
 84 
 85 // List<Element> childElements=root.elements();
 86 List<Element> childElements = root.elements("database");
 87 for (Element child : childElements) {
 88 // 获取属性 不知道属性名称时的遍历方法
 89 List<Attribute> attributes = child.attributes();
 90 // for (Attribute attribute : attributes) {
 91 // System.out.println(attribute.getName()+":"+attribute.getValue());
 92 // }
 93 String name = child.attributeValue("name");
 94 // String version = child.attributeValue("version");
 95 String version = child.attribute("version").getValue();
 96 System.out.println(name + ":" + version);
 97 
 98 // //获取子节点
 99 // List<Element> childs=child.elements();
100 // for (Element element : childs) {
101 // System.out.println(element.getName()+":"+element.getText());
102 // }
103 System.out.println(child.elementText("driver"));
104 System.out.println(child.element("url").getText());
105 System.out.println(child.elementTextTrim("user"));
106 System.out.println(child.element("password").getTextTrim());
107 
108 }
109 }
110 
111 public static void main(String[] args) throws Exception {
112 // new Dom4jHandler().read("data-source.xml");
113 // new Dom4jHandler().add();
114 new Dom4jHandler().update("data-source.xml");
115 }
116 }