xmlutil.java

XMLUtil.java/ java 解析XML源码

package com.asiainfo.aiox.ovsd.common;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.XMLWriter;

public class XMLUtil {
    private static Log logger = LogFactory.getLog(XMLUtil.class);
	public XMLUtil() {
		super();
		// TODO Auto-generated constructor stub
	}
	/**
	 * 将fromPath文件夹中的filename文件，移除到toPath
	 * @param fromPath String 源文件目录 d:\\temp\\source
	 * @param toPath String 目标文件目录 d:\\temp\\bak
	 * @param name String 要移动的文件 EVT_HELLO.txt
	 * @throws IOException 
	 */
	public static void moveFile(String fromPath, String toPath, String filename) throws IOException {
		
		/**源文件*/
		String sourceFileName=fromPath+File.separatorChar+filename;
		String bakFileName=toPath+File.separatorChar+filename;
		File sourceFile=new File(sourceFileName);
		if(!sourceFile.exists())
			return;
		mkdir(toPath);
		
		String tmpBakFileName=bakFileName+".tmp";
		createNewFile(tmpBakFileName);	
		
		/** 开始拷贝复制 */
		FileInputStream fis = new FileInputStream(sourceFile);
		FileOutputStream fos = new FileOutputStream(new File(tmpBakFileName));
		byte[] buf = new byte[1024];
		int i = 0;
		while ((i = fis.read(buf)) != -1) {
			fos.write(buf, 0, i);
		}
		fis.close();
		fos.close();
		sourceFile.delete();
		File file=new File(tmpBakFileName);
		File destFile=new File(bakFileName);
		if(destFile.exists())
			destFile.delete();
		file.renameTo(destFile);
	}
	/**
	 * 创建文件目录
	 * @param folderPath
	 */
	public static void mkdir(String folderPath)
	{
		File file=new File(folderPath);
		if(!file.exists())
			file.mkdirs();
	}
	/**
	 * 创建文件，如果原先存在，则删除该文件
	 * @param filename String 文件的绝对路径
	 * @throws IOException 
	 */
	public static void createNewFile(String filename) throws IOException
	{
		File file=new File(filename);
		if(file.exists())
			file.delete();
		else
			file.createNewFile();
	}
	/**
	 * <p>
	 * 将dom4j节点根据encoding格式保存到文件filename中
	 * </p>
	 * 
	 * @param root
	 *            Element 根节点
	 * @param filename
	 *            String 待保存文件的绝对路径及文件名
	 * @param encoding
	 *            String 待保存文件的格式，null或""的时候为"utf-8"格式
	 * @return
	 * @throws IOException
	 */
	public static void writeToFile(Element root, String filename,
			String encoding) throws IOException {
		int pos = filename.lastIndexOf(File.separatorChar);
		String path = filename.substring(0, pos);
		mkdir(path);
		createNewFile(filename);
		Document document = root.getDocument();
		if(document==null)
		{	
			document=DocumentHelper.createDocument();
			document.add(root);
		}
		OutputFormat format = OutputFormat.createPrettyPrint();
		if (encoding == null || "".equals(encoding.trim()))
			format.setEncoding("utf-8");
		else
			format.setEncoding(encoding);
		XMLWriter writer = new XMLWriter(new FileOutputStream(filename), format);
		writer.write(document);
		writer.close();
	}
   
   /**
     * <root> <a> <b></b> <b></b></a><a><a> <root> 
     * 如果想得到第2个Element b，xPath的格式为“/a@1/b@2”
     * 
     * @param root
     * @param xPath
     * @return
     */
    public static List getNodeList(Element root, String xPath)
    {
        String helpMessage ="Parameter error."+
            "For instance:     \n" 
                    + "* <root> \n"
                    + "*     <a>\n" 
                    + "*        <b>\n" 
                    + "*        </b>\n"
                    + "*        <b>\n" 
                    + "*        </b>\n"
                    + "*     </a>\n" 
                    + "*     <a>\n" 
                    + "*     </a>\n" 
                    + "* <root>\n"
                    + "* if want to get the second Element b，the xPath should be like “/a@1/b@2”";
        if (root == null || xPath == null || !xPath.startsWith("/"))
        {
            logger.error(helpMessage);
            return null;
        }
        String[] paths = xPath.split("/");
        List result = new ArrayList();
        List tempResult =null;
        int which = 1;
        boolean isSet = false;
        String temp = null;
        for (int i = 1; i < paths.length; i++)
        {
            paths[i] = paths[i].trim();
            if (paths[i].length() == 0)
            {
                logger.error("The path value '"+xPath+"' is wrong !");
                logger.error(helpMessage);
                return null;
            }
            if (paths[i].indexOf("@") != -1)
            {
                temp = paths[i].substring(paths[i].indexOf("@") + 1);
                
                try
                {
                    which = Integer.parseInt(temp);
                    isSet = true;
                }
                catch (NumberFormatException e)
                {
                    logger.error("The path value " + paths[i]
                            + " is wrong!");
                    return null;
                }
                
                paths[i] = paths[i].substring(0,paths[i].indexOf("@"));
            }
            tempResult = root.elements(paths[i]);
            if (tempResult == null || tempResult.size() < 1)
            {
                logger.error("Can't find this element,root = "
                        + root.getName() + ";path = " + paths[i]);
                return null;
            }
            if (which > tempResult.size() || which <= 0)
            {
                logger.error("The sequence '" + which + "' of path value '"
                        + paths[i] + "' is wrong!");
                return null;
            }

            if( i == paths.length -1)
            {
                if (isSet)
                {
                    result.clear();
                    result.add(tempResult.get(which-1));
                }
                else
                {
                    result = tempResult;
                }
            }
            else
            {
                root = (Element) tempResult.get(which-1); 
            }
            isSet = false;
            which = 1;
        }

        return result;
    }

}