java w3c dom 解析 xml

川长思鸟来 2022-06-05 03:35 227阅读 0赞

1.config.xml 文件

<?xml version="1.0"?>  
    <config>  
        <strategy>1
            <type>student</type>2
            <className>com.design.action.strategy.chapter02.StudentDiscount</className>
        </strategy>
        <strategy>
            <type>vip</type>
            <className>com.design.action.strategy.chapter02.VIPDiscount</className>
        </strategy>
        <strategy>
            <type>children</type>
            <className>com.design.action.strategy.chapter02.ChildrenDiscount</className>
        </strategy>
    </config>

2.解析文件

package com.design.action.strategy.chapter02;
    
    import java.io.File;
    import java.util.HashMap;
    import java.util.Map;
    
    import javax.xml.parsers.DocumentBuilder;
    import javax.xml.parsers.DocumentBuilderFactory;
    
    import org.w3c.dom.Document;
    import org.w3c.dom.Node;
    import org.w3c.dom.NodeList;
    
    /** * 打折管理器 * @author zhangtengda * */
    public class DiscountManager2 {
        public static void main(String[] args) {
            DiscountManager2 manager = new DiscountManager2();
    
        }
    
        public DiscountManager2() {
            init();
        }
        /** * 初始化打折对象 */
        public void init() {
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
            DocumentBuilder builder;
            try {
    
                builder = factory.newDocumentBuilder();
                Document document = builder.parse(new File(DiscountManager2.class.getResource("").getPath() + "\\config.xml"));
                NodeList nlForType = document.getElementsByTagName("strategy");
                for(int i=0; i < nlForType.getLength(); i++) { 
                    Node typeNode = nlForType.item(i);
                    NodeList list = typeNode.getChildNodes();
                    // 解析 strategy 内容，注意 xml 解析一个节点的子节点的时候，取得是 1,3,5这样的奇数所以你，因为0,2,4都是属于这个中间的值，即便是空也是会占据位置的
                    Node v0 = list.item(0);
                    System.out.println(v0.getNodeValue().trim());
                    Node v2 = list.item(2);
                    System.out.println(v2.getNodeValue().trim());
                    Node type = list.item(1).getFirstChild();
                    Node className = list.item(3).getFirstChild();
                    String typeStr = type.getNodeValue().trim();
                    String classNameStr = className.getNodeValue().trim();
                    System.out.println(typeStr);
                    System.out.println(classNameStr);
                }
    
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

结果：

1
    2
    student
    com.design.action.strategy.chapter02.StudentDiscount
    
    
    vip
    com.design.action.strategy.chapter02.VIPDiscount
    
    
    children
    com.design.action.strategy.chapter02.ChildrenDiscount