java url 获取文件_[转]从URL获取文件保存到本地的JAVA代码,url 请求设置http请求头

url下载文件的地方.参数需要 urlencode..否则会下载不到.

 

java url 获取文件_[转]从URL获取文件保存到本地的JAVA代码,url 请求设置http请求头

    public boolean saveUrlAs(String photoUrl, String fileName) {
//此方法只能用户HTTP协议
        try {
            URL url = new URL(photoUrl);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            DataInputStream in = new DataInputStream(connection.getInputStream());
            DataOutputStream out = new DataOutputStream(new FileOutputStream(fileName));
            byte[] buffer = new byte[4096];
            int count = 0;
            while ((count = in.read(buffer)) > 0) {
                out.write(buffer, 0, count);
            }
            out.close();
            in.close();
            return true;
        } catch (Exception e) {
            return false;
        }
    }

    public String getDocumentAt(String urlString) {
//此方法兼容HTTP和FTP协议
        StringBuffer document = new StringBuffer();
        try {
            URL url = new URL(urlString);
            URLConnection conn = url.openConnection();
            BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
            String line = null;
            while ((line = reader.readLine()) != null) {
                document.append(line + "\n");
            }
            reader.close();
        } catch (MalformedURLException e) {
            System.out.println("Unable to connect to URL: " + urlString);
        } catch (IOException e) {
            System.out.println("IOException when connecting to URL: " + urlString);
        }
        return document.toString();
    }

<% //测试

        String photoUrl="http://ad4.sina.com.cn/200601/12/43932_750450.jpg";
        String fileName=photoUrl.substring(photoUrl.lastIndexOf("/"));
        String filePath="d:/ghost/";
        boolean flag=saveUrlAs(photoUrl,filePath+fileName);
        out.println("Run ok!\n                Get URL file"+flag);
        %>


        设置http请求头
        HttpURLConnection.setRequestProperty（String key，String value）;
        //设置请求头
        conn.setRequestProperty("Charsert", "UTF-8");
        conn.setRequestProperty("Content-Type", "application/json; charset=UTF-8");//设置参数类型是json格式
        conn.setRequestProperty("Connection", "Keep-Alive");
        conn.setRequestProperty("logType", "base");