IO读取写入xml文件

以学生对象为例

员工类

package com.situ.chapterwork;

public class Student {
    private int id;
    private String name;
    private String sex;
    private int age;
    

    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    @Override
    public String toString() {
	return "Student [id=" + id + ", name=" + name + ", sex=" + sex + ", age=" + age + "]";
    }

    
    
}

main函数

包含读取xml文件和写入xml文件

package com.situ.chapterwork;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;

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

public class Main {

    public static void main(String[] args) {
	List<Student> list  = new ArrayList<>();
	
	fecth(list);//读取xml文件信息
	
	//打印看一下读取是否正确
	for(Student s:list) {
	System.out.println(s);
	}
	stroe(list);//存储信息到xml文件
	
    }

    private static void stroe(List<Student> list) {//这里指明Student对象，后面就可以直接用，不用把Student变成接口
	// TODO Auto-generated method stub
	File file = new File("D:/Test/student.xml");
	
	 try {
	     
	     Document document = DocumentHelper.createDocument();
	     Element doc = document.addElement("class");
	     Element students = doc.addElement("students");
	     for(Student s :list) {
		  Element student= students.addElement("student");
		 student.addAttribute("id", Integer.toString(s.getId()));
		 Element name = student.addElement("name");
		 Element sex = student.addElement("sex");
		 Element age = student.addElement("age");
		 name.setText(s.getName());
		 sex.setText(s.getSex());
		 age.setText(Integer.toString(s.getAge()));
		 }
	     	//写入xml
	     OutputFormat format = OutputFormat.createPrettyPrint();//代码风格
	     format.setEncoding("UTF-8");//代码编码格式
		 XMLWriter writer = new XMLWriter(new FileOutputStream(file),format);//新建文件流，写入xml文件
		 
		 //写入一个文档
		 writer.write(document);
		 writer.close();
	      
	} catch (FileNotFoundException e) {
	     //TODO Auto-generated catch block
	    e.printStackTrace();
	} catch (UnsupportedEncodingException e) {
	     //TODO Auto-generated catch block
	    e.printStackTrace();
	} catch (IOException e) {
	     //TODO Auto-generated catch block
	    e.printStackTrace();
	}
    }

    private static void fecth(List<Student> list) {//这里指明Student对象，后面就可以直接用，不用把Student变成接口
	// TODO Auto-generated method stub
	InputStream is = Thread.currentThread().getContextClassLoader().getResourceAsStream("com/situ/chapterwork/employee.xml");
	SAXReader reader = new SAXReader();
	
	try {
	    //文档类
	    Document doc = reader.read(is);
	    //返回根节点
	    Element root = doc.getRootElement();
	    Element students = root.element("students");
	    List<Element> studentList = students.elements();
	    
	    for(Element e:studentList) {//遍历集合
		Student stu1 = new Student();
		stu1.setId(Integer.valueOf(e.attributeValue("id")).intValue());//Integer.parseInt(string)字符串转整形
		stu1.setName(e.element("name").getText());
		stu1.setSex(e.element("sex").getText());
		stu1.setAge(Integer.valueOf(e.element("age").getText()));//Integer.parseInt(string)字符串转整形
		list.add(stu1);
	    }  
	    
	} catch (DocumentException e) {
	    // TODO Auto-generated catch block
	    e.printStackTrace();
	}finally {
	    try {
		is.close();//关闭流
	    } catch (IOException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	    }
	}
    }
}

xml文件

<?xml version="1.0" encoding="UTF-8"?>
<class>
	<students>
		<student id="1">
			<name>王一</name>
			<sex>男</sex>
			<age>20</age>
		</student>
	
		<student id ="2">
			<name>李二</name>
			<sex>男</sex>
			<age>21</age>
		</student>
	
		<student id="3">
			<name>张三</name>
			<sex>女</sex>
			<age>20</age>
		</student>
	
		<student id="4">
			<name>王五</name>
			<sex>男</sex>
			<age>22</age>
		</student>
		
		<students id = "5">
			<name>马六</name>
			<sex>女</sex>
			<age>18</age>
		</students>
	</students>
</class>

输出后的xml文件

写入xml文件与序列化一致，只不过按照了xml文件格式读取写入