InputStream 转为byte[]字节数组

源自：http://blog.csdn.net/zdwzzu2006/article/details/7745827

可以参考以下代码：

public static byte[] toByteArray(InputStream input) throws IOException {    ByteArrayOutputStream output = new ByteArrayOutputStream();    byte[] buffer = new byte[4096];    int n = 0;    while (-1 != (n = input.read(buffer))) {        output.write(buffer, 0, n);    }    return output.toByteArray();}