xml转换

淡淡的烟草味﹌ 2022-08-19 11:16 187阅读 0赞

package util;

import java.io.FileInputStream;  
import java.io.FileOutputStream;  
import java.util.ArrayList;  
import java.util.List;

import org.dom4j.Document;  
import org.dom4j.DocumentHelper;  
import org.dom4j.Element;  
import org.dom4j.io.OutputFormat;  
import org.dom4j.io.SAXReader;  
import org.dom4j.io.XMLWriter;

import entity.Emp;

/\*\*  
\* 员工XML解析器  
\*/  
public class EmpXmlParser \{

/**
     * 1.写XML，将员工数据写入到emp.xml中
     */
    public static void emp2xml() 
        throws Exception {
        //模拟员工数据
        Emp e = new Emp();
        e.setId(1);
        e.setName("张三");
        e.setAge(25);
        e.setSalary(6000.00);
        e.setType("simple");
    
        //创建文档对象
        Document doc = 
            DocumentHelper.createDocument();
        //创建根元素
        Element root = doc.addElement("emp");
        //在根元素下创建各子元素
        root.addElement("id").addText(
                e.getId().toString());
        root.addElement("name").addText(
                e.getName());
        root.addElement("age").addText(
                e.getAge().toString());
        root.addElement("salary").addText(
                e.getSalary().toString());
        //创建根元素的属性
        root.addAttribute("type", e.getType());
    
        //将文档对象输出
        XMLWriter writer = new XMLWriter(
                new FileOutputStream("d:\\xml\\emp.xml"),
                OutputFormat.createPrettyPrint());
        writer.write(doc);
        writer.close();
    }
    
    /**
     * 2.读取XML，将数据写入Emp对象中
     */
    public static void xml2emp() throws Exception {
        SAXReader reader = new SAXReader();
        //读取xml
        Document doc = reader.read(
                new FileInputStream(
                        "d:\\xml\\emp.xml"));
        Emp e = new Emp();
        //读取根元素
        Element root = doc.getRootElement();
        //读取根元素的下级元素
        e.setId(Integer.valueOf(
                root.elementText("id")));
        e.setName(root.elementText("name"));
        e.setAge(Integer.valueOf(
                root.elementText("age")));
        e.setSalary(Double.valueOf(
                root.elementText("salary")));
        //读取根元素的属性
        e.setType(root.attributeValue("type"));
    
        System.out.println("ID:" + e.getId());
        System.out.println("Name:" + e.getName());
        System.out.println("Age:" + e.getAge());
        System.out.println("Salary:" + e.getSalary());
        System.out.println("Type:" + e.getType());
    }
    
    /**
     * 将一组Emp数据写入到一个XML文件中
     */
    public static void emps2xml() throws Exception {
        List<Emp> emps = new ArrayList<Emp>();
        Emp e1 = new Emp();
        e1.setId(1);
        e1.setName("张三");
        e1.setAge(25);
        e1.setSalary(6000.00);
        e1.setType("simple");
        emps.add(e1);
        Emp e2 = new Emp();
        e2.setId(2);
        e2.setName("李四");
        e2.setAge(26);
        e2.setSalary(7000.00);
        e2.setType("simple");
        emps.add(e2);
        Emp e3 = new Emp();
        e3.setId(3);
        e3.setName("王五");
        e3.setAge(27);
        e3.setSalary(8000.00);
        e3.setType("Leader");
        emps.add(e3);
    
        Document doc = 
            DocumentHelper.createDocument();
        //创建根元素
        Element root = doc.addElement("emps");
        for(Emp emp : emps){
            Element parent = root.addElement("emp");
            parent.addElement("id").addText(
                    emp.getId().toString());
            parent.addElement("name").addText(
                    emp.getName());
            parent.addElement("age").addText(
                    emp.getAge().toString());
            parent.addElement("salary").addText(
                    emp.getSalary().toString());
            parent.addAttribute("type", emp.getType());
        }
        //输入到XML
        XMLWriter writer = new XMLWriter(
                new FileOutputStream("d:\\xml\\emps.xml")
                ,OutputFormat.createPrettyPrint());
        writer.write(doc);
        writer.close();
    }
    
    /**
     * 4.从XML中读取一组Emp数据
     */
    public static void xml2emps() throws Exception {
        SAXReader reader = new SAXReader();
        List<Emp> emps = new ArrayList<Emp>();
        //读取XML文件
        Document doc = reader.read(
                new FileInputStream(
                        "d:\\xml\\emps.xml"));
        //读取根元素emps
        Element root = doc.getRootElement();
        List<Element> elems = root.elements("emp");
        for(Element elem : elems){
            Emp e = new Emp();
            e.setId(Integer.valueOf(
                    elem.elementText("id")));
            e.setName(elem.elementText("name"));
            e.setAge(Integer.valueOf(
                    elem.elementText("age")));
            e.setSalary(Double.valueOf(
                    elem.elementText("salary")));
            e.setType(elem.attributeValue("type"));
            emps.add(e);
        }
        for(Emp e : emps){
            System.out.println(
                e.getId() + " " +e.getName()    
            );
        }
    }
    
    /**
     * xpath演示示例
     */
    public static void xpath() throws Exception {
        SAXReader reader = new SAXReader();
        Document doc = reader.read(
                    new FileInputStream(
                            "d:\\xml\\emps.xml"));

// List elems =  
// doc.selectNodes(“/emps/emp\[1\]”);  
// List elems =  
// doc.selectNodes(“/emps/emp\[@type=’Leader’\]”);  
List elems =  
doc.selectNodes(“/emps/emp\[id=’2’\]”);  
Element parent = elems.get(0);  
System.out.println(parent.elementText(“id”));  
System.out.println(parent.elementText(“name”));  
\}

public static void main(String[] args)
        throws Exception {

// emp2xml();  
// xml2emp();  
// emps2xml();  
// xml2emps();  
xpath();  
\}