def areStreamsEqual(stream1: InputStream,stream2: InputStream): Boolean =
{
    val one = stream1.read()
    val two = stream2.read()
    if(one != two)
        false
    else if(one == -1 && two == -1)
        true
    else
        areStreamsEqual(stream1,stream2)
}

反正是否强制Scala编译器在这里进行尾调用优化？