工具类

public class StreamTools {

    /**
     * 字节流转化成字符串
     */
    public static String readFromNetWork(InputStream is){


        try {

            ByteArrayOutputStream baos = new ByteArrayOutputStream();

            byte[] buffer = new byte[1024];
            int len = 0;
            while ((len = is.read(buffer)) != -1){

                baos.write(buffer,0,len);

            }

            is.close();
            baos.close();
            return baos.toString();

        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;

    }