java – 如何编码Stream.findNth()?
发布时间:2020-12-15 04:30:40 所属栏目:Java 来源:网络整理
导读:与Stream.findFirst()类似,有没有办法编写Stream.findNth()? 我正在通过重写一些遗留代码来练习Java 8.而且,我想知道如何使用Stream API编写以下函数. static curPipeNumber = 0;/** skipToEntry() updates 'curPipeNumber' to 'pipeNumber' and returns th
与Stream.findFirst()类似,有没有办法编写Stream.findNth()?
我正在通过重写一些遗留代码来练习Java 8.而且,我想知道如何使用Stream API编写以下函数. static curPipeNumber = 0; /** skipToEntry() updates 'curPipeNumber' to 'pipeNumber' and returns the first byte position of the word before the ('pipeNumber')-th pipe. * It does so by reading and ignoring unnecessary bytes from the buffer. * e.g.,*/ static int skipToEntry(byte[] buf,int len,int nextByteToBeRead,int pipeNumber) { if(curPipeNumber == pipeNumber) return nextByteToBeRead; for(; nextByteToBeRead < len; nextByteToBeRead++) { if(buf[nextByteToBeRead] == '|') { ++curPipeNumber; if(curPipeNumber == pipeNumber) { return ++nextByteToBeRead; } } } return nextByteToBeRead; } 我希望它会转化为: static int skipToEntry(byte[] buf,int pipeNumber) { if(curPipeNumber == pipeNumber) return nextByteToBeRead; OptionalInt pipeIndex = IntStream.range(i,len) .filter(n -> buf[n] == '|') .findNth(pipeNumber); curPipeNumber = pipeNumber; nextByteToBeRead = pipeIndex.getAsInt() + 1; return nextByteToBeRead; } 解决方法OptionalInt result = stream.skip(n-1).findFirst(); (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |