一.DOM
studentx.xml
<?xml version="1.0"?> <students> <student> <name>John</name> <grade>B</grade> <age>12</age> </student> <student> <name>Mary</name> <grade>A</grade> <age>11</age> </student> <student> <name>Simon</name> <grade>A</grade> <age>18</age> </student> </students>
XMLParser.java
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.Node; import org.w3c.dom.NodeList; public class XMLParser { public void getAllUserNames(String fileName) { try { //1.获得一个文档解析器工厂：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 DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); //2.获得一个文档解析器：定义从XML文档获取DOM文档实例的API。 使用这个类，应用程序员可以从XML获得一个Document 。 DocumentBuilder db = dbf.newDocumentBuilder(); File file = new File(fileName); if (file.exists()) { //3.解析器解析xmL文件，获得一个DOM文档 Document doc = db.parse(file); //4.通过DOM文档获取根结点元素，并打印 Element docEle = doc.getDocumentElement(); System.out.println("Root element of the document: "+ docEle.getNodeName()); //5.通过DOM文档根据标签名获取所有其对应的结点，并将其存储在NodeList抽象集合中 NodeList studentList = docEle.getElementsByTagName("student"); System.out.println("Total students: " + studentList.getLength()); //6.打印"student"结点下所有的结点信息 if(studentList != null && studentList.getLength() > 0) { for(int i = 0; i < studentList.getLength(); i++) { //7.遍历一个"student"结点 Node node = studentList.item(i); //8.node.getNodeType() == Node.ELEMENT_NODE，表示node结点是一个Element(一组) if(node.getNodeType() == Node.ELEMENT_NODE) { System.out.println("====================="); Element e = (Element) node; NodeList nodeList = e.getElementsByTagName("name"); System.out.println("Name: "+ nodeList.item(0).getChildNodes().item(0).getNodeValue()); nodeList = e.getElementsByTagName("grade"); System.out.println("Grade: "+nodeList.item(0).getChildNodes().item(0) .getNodeValue()); nodeList = e.getElementsByTagName("age"); System.out.println("Age: "+ nodeList.item(0).getChildNodes().item(0).getNodeValue()); } } } } } catch (Exception e) { System.out.println(e); } } public static void main(String[] args) { XMLParser parser = new XMLParser(); parser.getAllUserNames("./src/students.xml"); } }
2.XPath方式
users.xml
<?xml version="1.0"?> <users> <user id="1"> <name>张三</name> <createTime>2018-10-15</createTime> <password>123</password> <phone>10086</phone> <nickName>阿毛</nickName> </user> <user id="2"> <name>李四</name> <createTime>2018-10-15</createTime> <password>234</password> <phone>12306</phone> <nickName>二狗子</nickName> </user> </users>
import java.text.DateFormat; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Date; public class UserEntity { private Long id; private String name; private Date createTime; private String password; private String phone; private String nickName; static UserEntity buildUserEntity(String id, String name, String createTime, String password, String phone, String nickName) throws ParseException { UserEntity user=new UserEntity(); user.id=Long.valueOf(id); user.name=name; user.createTime=new SimpleDateFormat("yyyy-MM-dd").parse(createTime); user.password=password; user.nickName=nickName; return user; } @Override public String toString() { // TODO Auto-generated method stub return id+"-"+name+"-"+createTime+"-"+password+"-"+nickName; } }
import java.io.File; import java.io.FileReader; import java.util.ArrayList; import java.util.Date; import java.util.List; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.xpath.XPath; import javax.xml.xpath.XPathConstants; import javax.xml.xpath.XPathFactory; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; public class XMLParser { public void getAllUserNames(String fileName) { try { //1.获得一个文档解析器工厂：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 DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); //2.获得一个文档解析器：定义从XML文档获取DOM文档实例的API。 使用这个类，应用程序员可以从XML获得一个Document 。 DocumentBuilder builder = dbf.newDocumentBuilder(); File file=new File(fileName); //3.通过解析器解析xml文件，获得一个文档对象 Document document=builder.parse(file); //4.获取新的XPathFactory实例 XPathFactory xpathFactory=XPathFactory.newInstance(); //5.一个XPathFactory实例可以用来创建XPath对象 XPath xpath=xpathFactory.newXPath(); //6.xpath根据根结点"users"标签解析document文档 NodeList nodeList=(NodeList) xpath.evaluate("/users/*", document,XPathConstants.NODESET); //7.获取一个ArrayList实例用来存储UserEntity对象 List<UserEntity> userList=new ArrayList<UserEntity>(); //8.获取所有的user结点 for(int i=1;i<nodeList.getLength()+1;i++) { String path="/users/user["+i+"]"; String id=(String) xpath.evaluate(path+"/@id", document,XPathConstants.STRING); String name=(String) xpath.evaluate(path+"/name", document,XPathConstants.STRING); String createTime=(String) xpath.evaluate(path+"/createTime", document,XPathConstants.STRING); String password=(String) xpath.evaluate(path+"/password", document,XPathConstants.STRING); String phone=(String) xpath.evaluate(path+"/phone", document,XPathConstants.STRING); String nickName=(String) xpath.evaluate(path+"/nickName", document,XPathConstants.STRING); //调用buildUserEntity()方法构建UserEntity对象 UserEntity userEntity=UserEntity.buildUserEntity(id,name,createTime,password,phone,nickName); userList.add(userEntity); } for(UserEntity user:userList) { System.out.println(user); } }catch(Exception e){ e.getMessage(); } } public static void main(String[] args) { XMLParser parser = new XMLParser(); parser.getAllUserNames("./src/users.xml"); } }
3.dom4j
1.引入依赖
<!-- dom4j解析xml --> <dependency> <groupId>dom4j</groupId> <artifactId>dom4j</artifactId> <version>1.6.1</version> </dependency>
2.application.xml
<?xml version="1.0" encoding="UTF-8"?> <beans> <bean id="userDao" class="cn.yiguang.testProject.annotation.UserDaoImpl"></bean> <bean id="user1Dao" class="cn.yiguang.testProject.annotation.User1DaoImpl"></bean> <bean id="user2Dao" class="cn.yiguang.testProject.annotation.User2DaoImpl"></bean> <bean id="userService" class="cn.yiguang.testProject.annotation.UserServiceImpl"></bean> </beans>
3.BeanDefine.java
public class BeanDefine { private String id; private String className; public BeanDefine(String id, String className) { this.id = id; this.className = className; } public String getId() { return id; } public void setId(String id) { this.id = id; } public String getClassName() { return className; } public void setClassName(String className) { this.className = className; } @Override public String toString() { return "id:"+id+",className:"+className; } }
4.测试
import java.util.Iterator; import org.dom4j.Document; import org.dom4j.DocumentException; import org.dom4j.Element; import org.dom4j.io.SAXReader; public class Test { public static void main(String[] args) { // 读取xml文件,转换成Document结点 Document document = null; // 创建一个SAXReader解析器 SAXReader saxReader = new SAXReader(); try { ClassLoader classLoader = Thread.currentThread().getContextClassLoader(); document = saxReader.read(classLoader.getResourceAsStream("configAnnotation.xml")); Element beans = document.getRootElement(); for (Iterator<Element> beansList = beans.elementIterator();beansList.hasNext();) { Element element = beansList.next(); BeanDefine bean = new BeanDefine(element.attributeValue("id"), element.attributeValue("class")); System.out.println(bean.toString()); } }catch (DocumentException e){ System.out.println("解析配置文件出错......"); } } }
