JAVA檔案的下載

	/**
	 * 下載檔案
	 * 
	 * @param savepath 儲存路徑
	 * @param resurl  資源路徑
	 * @param fileName  自定義資源名
	 */
	public String getInternetRes(String savepath, String resurl, String fileName) {
        URL url = null;
        HttpURLConnection con = null;
        InputStream in = null;
        FileOutputStream out = null;
        File res = null;
        try {
            url = new URL(resurl);
            //建立http連線，得到連線物件
            con = (HttpURLConnection) url.openConnection();
            in = con.getInputStream();
            byte[] data = getByteData(in);//轉化為byte陣列

            File file = new File(savepath);
            if (!file.exists()) {
                file.mkdirs();
            }

            res = new File(file + File.separator + fileName);
            out = new FileOutputStream(res);
            out.write(data);
            logger.info("downloaded successfully!!!");
        } catch (IOException e) {
           logger.error(e.getMessage() , e);
        } finally {
            try {
                if (null != out)
                    out.close();
                if (null != in)
                    in.close();
            } catch (IOException e) {
               logger.error(e.getMessage() , e);
            }
        }
        
        return res.toString();
    }
	
	/**
     * 從輸入流中獲取位元組陣列
     * 
     * @param in
     * @return
     * @throws IOException
     */
    private byte[] getByteData(InputStream in) throws IOException {
        byte[] b = new byte[1024];
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        int len = 0;
        while ((len = in.read(b)) != -1) {
            bos.write(b, 0, len);
        }
        if(null!=bos){
            bos.close();
        }
        return bos.toByteArray();
    }
 

2、修改檔名

/**
     * 修改檔名字
     * @param filePath 檔案路徑
     * @param newName 新的檔名
     * @return
     */
    public boolean updateFileName(String filePath , String newName){
    	File f = new File(filePath);
		String c = f.getParent();
		File mm = new File(c + sb.toString());
		if (f.renameTo(mm)) {
			return true;
		} else {
			return false;
		}
    }
 

/**
     * 刪除檔案
     * @param filePath  檔案路徑
     * @param format  檔案字尾
     */
    public void deleteFile(String filePath , String format){
    	StringBuffer sb = new StringBuffer(filePath);
    	sb.append(format);
    	File f = new File(sb.toString()); 
    	if(f.exists())
    	    f.delete();
    }