读取流信息，转换成字符串并解决乱码问题

public class StreamTools {    /**     * 读取流信息     * @param in     * @return     * @throws IOException      */    public static String readStream(InputStream in) throws IOException{        //定义一个内存输入流 , bos不用关闭，关闭无效        ByteArrayOutputStream bos=new ByteArrayOutputStream();        int len=-1;        byte buffer[] = new byte[1024];        while ((len=in.read(buffer))!=-1) {            bos.write(buffer,0,len);                    }        in.close();        //解决乱码的问题        return new String(bos.toByteArray(),"gbk");    }}