java----DOM解析XML

Bertha 。 2021-10-24 06:26 298阅读 0赞

DOM：

直接一次性将XML文件读取到内存中，所以可以跨节点读取所需要的数据

适合服务器开发

import org.w3c.dom.Document;
    import org.w3c.dom.Node;
    import org.w3c.dom.NodeList;
    import org.xml.sax.Attributes;
    import org.xml.sax.SAXException;
    import org.xml.sax.helpers.DefaultHandler;
    
    import javax.xml.parsers.*;
    import java.io.IOException;
    import java.io.InputStream;
    import java.util.ArrayList;
    import java.util.List;
    
    public class Demo{
        public static void main(String[] args) throws IOException, SAXException, ParserConfigurationException {
            xmlTest();
        }
        public static void xmlTest() throws ParserConfigurationException, SAXException, IOException {
            //创建一个DOM解析器工厂对象;
            DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
            //通过工厂对象创建DOM解析器
            DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
            //解析文档
            InputStream resourceAsStream = Thread.currentThread().getContextClassLoader().getResourceAsStream("com\\first\\person.xml");
            Document doc = documentBuilder.parse(resourceAsStream);//doc 即为树状结构的存储对象,在内存中;
    
            ArrayList<Person> personList = new ArrayList<>();
            NodeList XMLpersonlist = doc.getElementsByTagName("person");
            Person person = null;
            for (int i = 0; i <XMLpersonlist.getLength(); i++) {
                person = new Person();
                //获取属性值
                String p_id = XMLpersonlist.item(i).getAttributes().getNamedItem("person_id").getNodeValue();
                person.setId(p_id);
                NodeList childNodes = XMLpersonlist.item(i).getChildNodes();
                for (int j = 0; j < childNodes.getLength(); j++) {
                    Node children_node = childNodes.item(j);
                    String node_name = children_node.getNodeName();
                    if ("name".equals(node_name)){
                        //把文本也看成一个节点，<name>zy</name> 中zy当做节点；children_node.getFirstChild()表示获取zy这个节点；
                        //zy.getNodeValue() 获取的值就是zy;
                        String p_name = children_node.getFirstChild().getNodeValue();
                        person.setName(p_name);
                    }else if ("age".equals(node_name)){
                        String p_age = children_node.getFirstChild().getNodeValue();
                        person.setAge(p_age);
                    }
                }
                personList.add(person);
            }
            personList.forEach((p)->System.out.println(p));
        }
    }
    
    class Person{
        private String name;
        private String age;
        private String id;
        public void setName(String name) {
            this.name = name;
        }
        public void setAge(String age) {
            this.age = age;
        }
        public void setId(String id) {
            this.id = id;
        }
        @Override
        public String toString() {
            return "Person{" +
                    "name='" + name + '\'' +
                    ", age='" + age + '\'' +
                    ", id='" + id + '\'' +
                    '}';
        }
    }

**XML文件**

<?xml version="1.0" encoding="UTF-8" ?>
    <Person>
        <person person_id="p1">
            <name>zy</name>
            <age>18</age>
        </person>
        <person person_id="p2">
            <name>zt</name>
            <age>20</age>
        </person>
    </Person>

转载于:https://www.cnblogs.com/yanxiaoge/p/10770695.html