src/org/nutz/lang/stream/QueueInputStream.java
public int peek() throws IOException{
        peekindex = 0;
        int v = peek(peekindex ++);
        if(v == -1){
            end = true;
        }
        return v;
    }
public int peek() throws IOException{
        peekindex = 0;
        int v = peek(peekindex ++);
        if(v == -1){
            end = true;
        }
        return v;
    }
访问头部字节, 不删除
@return 头部字节
@throws IOException