XML DOM解析XML文件

缺乏、安全感 2022-06-08 09:58 349阅读 0赞

采用DOM解析student.xml文件，将解析的每组数据保存在Student对象中，然后将Student对象添加到List集合。

注：解析器读入整个文档，然后构建一个驻留内存的树结构，使用 DOM 接口来操作这个树结构。

**一、解析的XML文件（student.xml）**

<?xml version="1.0" encoding="utf-8" ?>
    
    <!DOCTYPE class [
            <!ELEMENT student (name,age,sex,height)>
            <!ELEMENT name (#PCDATA)>
            <!ELEMENT age (#PCDATA)>
            <!ELEMENT sex (#PCDATA)>
            <!ELEMENT height (#PCDATA)>
            ]>
    
    
    <class>
        
        <student id="1" user="lisi">
            <name>李四</name>
            <age>18</age>
            <sex>男</sex>
            <height>182</height>
        </student>
        <student id="2" user="wangwu">
            <name>王五</name>
            <age>19</age>
            <sex>男</sex>
            <height>172</height>
        </student>
    </class>

**二、解析代码**

package com.xml.main;
    
    import org.w3c.dom.*;
    import org.xml.sax.SAXException;
    
    import javax.xml.parsers.DocumentBuilder;
    import javax.xml.parsers.DocumentBuilderFactory;
    import javax.xml.parsers.ParserConfigurationException;
    import java.io.File;
    import java.io.IOException;
    import java.util.ArrayList;
    
    public class DOMParseMain {
        public static void main(String[] args) {
            try {
    //            使用List存储解析到的学生信息
                ArrayList<Student> list = new ArrayList<>();
    
                //DOM解析的步骤
                //步骤一：创建DOM解析工厂
                DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
                //步骤二：通过解析工厂 创建一个XML文档解析者
                DocumentBuilder documentBuilder = factory.newDocumentBuilder();
                //步骤三： 解析指定XML文件
                Document document = documentBuilder.parse(new File("student.xml"));
                //开始解析
                Element documentElement = document.getDocumentElement();
                //获取根元素节点下所有的节点(包含此节点的所有子节点，如：元素节点，文本节点，注释节点，空格换行等)
                NodeList childNodes = documentElement.getChildNodes();
    
                for (int i = 0; i < childNodes.getLength(); i++) {
                    Node item = childNodes.item(i);
                    Student student = new Student();
    //                只获取元素节点并且节点名称为student
                    if (item.getNodeType() == Node.ELEMENT_NODE && "student".equals(item.getNodeName())) {
                        NamedNodeMap attributes = item.getAttributes();//得到Student所有的属性
                        Node id = attributes.getNamedItem("id");//获取id节点
                        String idValue = id.getNodeValue();//获取id的属性值
    
                        Node user = attributes.getNamedItem("user");//获取user节点
                        String userValue = user.getNodeValue();//获取user 属性值
    
                        //添加信息到student对象中
                        student.setId(Integer.parseInt(idValue));
                        student.setUser(userValue);
    
                        //遍历student节点下面的子节点
                        NodeList childNodes1 = item.getChildNodes();
                        for (int j = 0; j < childNodes1.getLength(); j++) {
                            Node item1 = childNodes1.item(j);
    //                        获取元素节点
                            if (item1.getNodeType() == Node.ELEMENT_NODE) {
                                switch (item1.getNodeName()) {
                                    case "name":
                                        String nameValue = item1.getFirstChild().getNodeValue();
                                        student.setName(nameValue);
                                        break;
                                    case "height":
                                        String heightValue = item1.getFirstChild().getNodeValue();
                                        student.setHeight(Double.parseDouble(heightValue));
                                        break;
                                    case "age":
                                        String ageValue = item1.getFirstChild().getNodeValue();
                                        student.setAge(Integer.parseInt(ageValue));
                                        break;
                                    case "sex":
                                        String sexValue = item1.getFirstChild().getNodeValue();
                                        student.setSex(sexValue);
                                        break;
                                }
                            }
                        }
                        list.add(student);
                    }
                }
    //遍历List
                for (Student s : list) {
                    System.out.println(s.toString());
                }
    
            } catch (ParserConfigurationException e) {
                e.printStackTrace();
            } catch (SAXException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
            }
        }
    }

**三、Student.java**

package com.xml.main;
    
    public class Student {
        private int id;
        private String user;
        private String name;
        private String sex;
        private int age;
        private double height;
    
        public Student() {
        }
    
        public Student(int id, String user, String name, String sex, int age, double height) {
            this.id = id;
            this.user = user;
            this.name = name;
            this.sex = sex;
            this.age = age;
            this.height = height;
        }
    
        public int getId() {
            return id;
        }
    
        public void setId(int id) {
            this.id = id;
        }
    
        public String getUser() {
            return user;
        }
    
        public void setUser(String user) {
            this.user = user;
        }
    
        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;
        }
    
        public double getHeight() {
            return height;
        }
    
        public void setHeight(double height) {
            this.height = height;
        }
    
        @Override
        public String toString() {
            return "Student{" +
                    "id=" + id +
                    ", user='" + user + '\'' +
                    ", name='" + name + '\'' +
                    ", sex='" + sex + '\'' +
                    ", age=" + age +
                    ", height=" + height +
                    '}';
        }
    }

**四、解析结果**

![Center][]

[Center]: /images/20220608/cd512658e2674f4285c011a44d8743a8.png