java 从网络Url中下载文件

转自：http://blog.csdn.net/xb12369/article/details/40543649

/**
     * 从网络Url中下载文件
     * @param urlStr
     * @param fileName
     * @param savePath
     * @throws IOException
     */
    public static void  downLoadFromUrl(String urlStr,String fileName,String savePath) throws IOException{
        URL url = new URL(urlStr);  
        HttpURLConnection conn = (HttpURLConnection)url.openConnection();  
                //设置超时间为3秒
        conn.setConnectTimeout(3*1000);
        //防止屏蔽程序抓取而返回403错误
        conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");

        //得到输入流
        InputStream inputStream = conn.getInputStream();  
        //获取自己数组
        byte[] getData = readInputStream(inputStream);    

        //文件保存位置
        File saveDir = new File(savePath);
        if(!saveDir.exists()){
            saveDir.mkdir();
        }
        File file = new File(saveDir+File.separator+fileName);    
        FileOutputStream fos = new FileOutputStream(file);     
        fos.write(getData); 
        if(fos!=null){
            fos.close();  
        }
        if(inputStream!=null){
            inputStream.close();
        }


        System.out.println("info:"+url+" download success"); 

    }



    /**
     * 从输入流中获取字节数组
     * @param inputStream
     * @return
     * @throws IOException
     */
    public static  byte[] readInputStream(InputStream inputStream) throws IOException {  
        byte[] buffer = new byte[1024];  
        int len = 0;  
        ByteArrayOutputStream bos = new ByteArrayOutputStream();  
        while((len = inputStream.read(buffer)) != -1) {  
            bos.write(buffer, 0, len);  
        }  
        bos.close();  
        return bos.toByteArray();  
    }  

    public static void main(String[] args) {
        try{
            downLoadFromUrl("http://101.95.48.97:8005/res/upload/interface/apptutorials/manualstypeico/6f83ce8f-0da5-49b3-bac8-fd5fc67d2725.png",
                    "百度.jpg","d:/resource/images/diaodiao/country/");
        }catch (Exception e) {
            // TODO: handle exception
        }
    }