Java解析xml四种方式
先看xml的格式
<?xml version="1.0" encoding="UTF-8"?> <xml-body> <student> <id>1</id> <name>zhanagsan</name> <age>14</age> <score>80</score> <height>179</height> <address>localhost</address> </student> <student> <id>2</id> <name>lisi</name> <age>16</age> <score>75</score> <height>175</height> <address>192.168.100.101</address> </student> </xml-body>
Java的bo 类
package com.test.dom4j; public class Student { private String name; private String age; private String address; private String score; private String height; private String id; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getAge() { return age; } public void setAge(String age) { this.age = age; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } public String getScore() { return score; } public void setScore(String score) { this.score = score; } public String getHeight() { return height; } public void setHeight(String height) { this.height = height; } public String getId() { return id; } public void setId(String id) { this.id = id; } @Override public String toString() { // TODO Auto-generated method stub return this.id+" "+this.name+" "+this.score+" "+this.address +" "+this.age+" "+this.score+" "+this.height; } }
第一种 Sax解析：
package com.test.sax; import java.io.File; import java.util.ArrayList; import java.util.List; 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; import com.test.dom4j.Student; public class SaxParseXml { public static void main(String args[]) throws Exception{ SAXParserFactory factory = SAXParserFactory.newInstance(); SAXParser sax = factory.newSAXParser(); BeanParse beanParse = new BeanParse(); File file = new File("d:\\1.xml"); sax.parse(file, beanParse); List<Student> list = beanParse.getList(); for(int i=0;i<list.size();i++){ System.out.println(list.get(i).getAddress()); } } } class BeanParse extends DefaultHandler { private Student student = null; private List<Student> list = null; private String preTag = null; public List<Student> getList() { return list; } public void setList(List<Student> list) { this.list = list; } public void startDocument() throws SAXException { list = new ArrayList<Student>(); } public void startElement(String uri, String localName, String name, Attributes attributes) throws SAXException { preTag = name; if ("student".equals(name)) { student = new Student(); } } public void characters(char[] ch, int start, int length) throws SAXException { if (student != null) { String data = new String(ch, start, length); if ("name".equals(preTag)) { student.setName(data); } if ("address".equals(preTag)) { student.setAddress(data); } if ("age".equals(preTag)) { student.setAge(data); } if ("height".equals(preTag)) { student.setHeight(data); } if ("id".equals(preTag)) { student.setId(data); } if ("score".equals(preTag)) { student.setScore(data); } } } public void endElement(String uri, String localName, String name) throws SAXException { if(student!=null&&"student".equals(name)){ list.add(student); } preTag = null; } }
第二种 dom4j
package com.test.dom4j; import java.io.File; import java.util.ArrayList; import java.util.Iterator; import java.util.List; import org.dom4j.Document; import org.dom4j.Element; import org.dom4j.io.SAXReader; public class Dom4jParseXml { public static File getFile(String fileName){ if(null!=fileName||"".equals(fileName)){ return new File(fileName); } return null; } public static List<Student> parseXml(String fileName) throws Exception{ List<Student> list = new ArrayList<Student>(); if(getFile(fileName)!=null){ File file = getFile(fileName); SAXReader readXml = new SAXReader(); //读入文档 Document document = readXml.read(file); //获取根节点下的子节点head Element element = document.getRootElement(); Iterator<Element> it = element.elementIterator("student"); while(it.hasNext()){ Element students = it.next(); Student student = new Student(); student.setAge(students.elementTextTrim("age")); student.setAddress(students.elementTextTrim("address")); student.setHeight(students.elementTextTrim("height")); student.setId(students.elementTextTrim("id")); student.setName(students.elementTextTrim("name")); student.setScore(students.elementTextTrim("score")); list.add(student); } } return list; } public static void main(String args[]) throws Exception{ List<Student> list = parseXml("d://1.xml"); for(int i=0;i<list.size();i++){ System.out.println(list.get(i).toString()); } } }
第三种 jdom解析
package com.test.jdom; import java.io.File; import java.io.FileInputStream; import java.io.InputStream; import java.util.ArrayList; import java.util.List; import org.jdom.Document; import org.jdom.Element; import org.jdom.input.SAXBuilder; import com.test.dom4j.Student; public class JdomParseXml { public static void main(String args[]) throws Exception{ List<Student> list = XmlParse(); for(int i=0;i<list.size();i++){ System.out.println(list.get(i).toString()); } } public static List<Student> XmlParse() throws Exception{ List<Student> students = new ArrayList<Student>(); SAXBuilder builder = new SAXBuilder(); InputStream inputStream = new FileInputStream(new File("d:\\1.xml")); Document document = builder.build(inputStream); Element root = document.getRootElement(); List<Element> list = root.getChildren(); for(int i=0;i<list.size();i++){ Student student = new Student(); student.setId(list.get(i).getChildText("id")); student.setAge(list.get(i).getChildText("age")); student.setName(list.get(i).getChildText("name")); student.setAddress(list.get(i).getChildText("address")); student.setScore(list.get(i).getChildText("score")); student.setHeight(list.get(i).getChildText("height")); students.add(student); } return students; } }
第四种：dom解析
package com.test.dom; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import org.w3c.dom.Document; import org.w3c.dom.Node; import org.w3c.dom.NodeList; public class DomParseXml { public static void main(String args[]) { DomParseXml(); } public static void DomParseXml() { // 实例化一个文档构建器工厂 DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); try { // 通过文档构建器工厂获取一个文档构建器 DocumentBuilder db = dbf.newDocumentBuilder(); // 通过文档通过文档构建器构建一个文档实例 Document doc = db.parse("d:\\1.xml"); // 获取所有名字为 “student” 的节点 NodeList nodeList = doc.getElementsByTagName("student"); int size1 = nodeList.getLength(); for (int i = 0; i < size1; i++) { Node n = nodeList.item(i); // 获取 n 节点下所有的子节点。 NodeList nodeList2 = n.getChildNodes(); int size2 = nodeList2.getLength(); for (int j = 0; j < size2; j++) { Node n2 = nodeList2.item(j); if (n2.hasChildNodes()) { System.out.println(n2.getNodeName() + " = " + n2.getFirstChild().getNodeValue()); } } } } catch (Exception ex) { ex.printStackTrace(); } } }
四种解析方式的比较：单纯从代码量来看jdom是最简单的解析方式，jdom出现的原因就是为了减少xml解析的代码量，但其内部解析还是用的sax，jdom解析缺点不灵活。
Sax解析：不需要读入全部的数据就开始解析，效率和性能较高。单向导航，无法定位文档层次，很难同时访问同一文档的不同部分数据。
dom4j解析：性能优越，功能强大。hibernate解析就是用的dom4j，api较为复杂。
dom解析：允许对数据和结构做出修改，但是dom解析占用资源较多。
