编辑xml文件

package com.test.xml;
import java.io.FileOutputStream;
import java.io.IOException;
import org.jdom2.Document;
import org.jdom2.Element;
import org.jdom2.JDOMException;
import org.jdom2.input.SAXBuilder;
import org.jdom2.output.Format;
import org.jdom2.output.XMLOutputter;

public class UpdateXml {
    public static void main(String[] args) throws JDOMException, IOException {
        // 以下三行为读取xml->doc的固定步骤。得到根元素
        SAXBuilder sb = new SAXBuilder();
        Document doc = sb.build("d:/2.xml");
        Element root = doc.getRootElement();
        
        Element e = root.getChild("appSettings");
        System.out.println(e.getText());
        Element e2 = root.getChild("limit");
        System.out.println(e2.getText());
        e2.setText("150");
        
        //以下4行为固定写入xml的格式，套用就行，将doc写回xml        
         Format f = Format.getPrettyFormat();
        // 相当于<?xml version="1.0" encoding="gbk"?>
        f.setEncoding("gbk");
        // 写进硬盘，这个套用就行。路径左斜杠，一个，右斜杠2个
        XMLOutputter xmlout = new XMLOutputter(f);
        xmlout.output(doc, new FileOutputStream("d:\\2.xml"));
    }

}