jdom处理的XML Document 和String 之间的相互转化

package util;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileWriter;
import java.io.StringReader;

import org.jdom.Document;
import org.jdom.input.SAXBuilder;
import org.jdom.output.Format;
import org.jdom.output.XMLOutputter;   

/**
 * JDOM 方式操作XML
 *
 * @author Watson Xu
 * @date 2011-5-3 下午02:20:49
 */
public class OperationXMLByJdom {
    /**
     * DOCUMENT格式化输出保存为XML
     *
     * @param doc JDOM的Document
     * @param filePath 输出文件路径
     * @throws Exception
     */
    public static void doc2XML(Document doc, String filePath) throws Exception{
        Format format = Format.getCompactFormat();
        format.setEncoding("UTF-8"); //设置XML文件的字符为UTF-8
        format.setIndent("     ");//设置缩进    

        XMLOutputter outputter = new XMLOutputter(format);//定义输出 ,在元素后换行，每一层元素缩排四格
        FileWriter writer = new FileWriter(filePath);//输出流
        outputter.output(doc, writer);
        writer.close();
    }   

    /**
     * 字符串转换为DOCUMENT
     *
     * @param xmlStr 字符串
     * @return doc JDOM的Document
     * @throws Exception
     */
    public static Document string2Doc(String xmlStr) throws Exception {
        java.io.Reader in = new StringReader(xmlStr);
        Document doc = (new SAXBuilder()).build(in);
        return doc;
    }   

    /**
     * Document转换为字符串
     *
     * @param xmlFilePath XML文件路径
     * @return xmlStr 字符串
     * @throws Exception
     */
    public static String doc2String(Document doc) throws Exception {
        Format format = Format.getPrettyFormat();
        format.setEncoding("UTF-8");// 设置xml文件的字符为UTF-8，解决中文问题
        XMLOutputter xmlout = new XMLOutputter(format);
        ByteArrayOutputStream bo = new ByteArrayOutputStream();
        xmlout.output(doc, bo);
        return bo.toString();
    }   

    /**
     * XML转换为Document
     *
     * @param xmlFilePath XML文件路径
     * @return doc Document对象
     * @throws Exception
     */
    public static Document xml2Doc(String xmlFilePath) throws Exception {
        File file = new File(xmlFilePath);
        return (new SAXBuilder()).build(file);
    }   

    public static void main(String[] args) {
        try{
            Document doc = xml2Doc("test.xml");
            System.out.println(doc);
            System.out.println(doc2String(doc));
            doc = string2Doc(doc2String(doc));
            doc2XML(doc, "1.xml");
        } catch (Exception e) {
            e.printStackTrace();
        }   

    }
}