XMLUtil.java

package designpattern.creational_pattern.simple_factory_pattern.v3;

import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import java.io.File;

public class XMLUtil {
    //该方法用于从XML配置文件中提取图表类型，并返回类型名
    public static String getChartType() {
        try {
//创建文档对象
            DocumentBuilderFactory dFactory = DocumentBuilderFactory.newInstance();
            DocumentBuilder builder = dFactory.newDocumentBuilder();
            Document doc;
            doc = builder.parse(new File("src\\designpattern\\creational_pattern\\simple_factory_pattern\\v3\\config.xml"));
//获取包含图表类型的文本节点
            NodeList nl = doc.getElementsByTagName("chartType");
            Node classNode = nl.item(0).getFirstChild();
            String chartType = classNode.getNodeValue().trim();
            return chartType;
        }
        catch(Exception e) {
            e.printStackTrace();
            return null;
        }
    }
}