Programming/Java

java tip : 파일을 가장 빨리 읽는 방법 / 효과적인 방법

woonizzooni 2019. 6. 13. 05:37

 

파일 크기, 단일 파일/복수개 파일 등 조건별 차이가 있겠지만,

다음과 같은 검색어 결과로 여러 개발자/경험자들의 검토 의견을 참고해보자

    "What is the fastest way to read a large file in Java"

    "How to Read a Large File Efficiently with Java"

    "How to read files quickly with java"

 

 

몇 가지만 적어두자..

 

2008/02/24 How to read files quickly

    http://nadeausoftware.com/articles/2008/02/java_tip_how_read_files_quickly

Conclusions

For the best Java read performance, there are four things to remember:

  • Minimize I/O operations by reading an array at a time, not a byte at a time. An 8Kbyte array is a good size.
  • Minimize method calls by getting data an array at a time, not a byte at a time. Use array indexing to get at bytes in the array.
  • Minimize thread synchronization locks if you don't need thread safety. Either make fewer method calls to a thread-safe class, or use a non-thread-safe class like FileChannel and MappedByteBuffer.
  • Minimize data copying between the JVM/OS, internal buffers, and application arrays. Use FileChannel with memory mapping, or a direct or wrapped array ByteBuffer.

 

Ultimate Guide for Reading Files in Java

    https://funnelgarden.com/java_read_file/

 

How to Read Text and Binary Files in Java (ULTIMATE GUIDE)

How to read files in Java 7, 8 and 9 with examples for BufferedReader, Scanner, InputStream, InputStreamReader, FileInputStream, BufferedInputStream, FileReader, new I/O classes, Guava and Apache Commons. READ LINE BY LINE TO STRING OR BYTE ARRAY.

funnelgarden.com

 

 

 

2018/04/09 How do I read a large file quickly in Java?

    https://www.quora.com/How-do-I-read-a-large-file-quickly-in-Java

 

How do I read a large file quickly in Java?

Answer (1 of 4): I answered this question in a long article documenting 15 different ways to read a file in Java and testing them against each other to see which one is fastest. I’m going to give you the fastest 3 methods here for reading a 1 GB file: 1) j

www.quora.com

 

 

2019/03/06 Java NIO FileChannel vs FileOutputstream 성능/유용성

    https://codeday.me/ko/qa/20190306/9122.html

 

Java NIO FileChannel 대 FileOutputstream 성능/유용성 - 코드 로그

우리가 nio FileChannel 대 일반 FileInputStream / FileOuputStream을 사용하여 파일 시스템에 파일을 읽고 쓸 때 성능 (또는 장점)에 차이가 있는지를 파악하려고합니다. 나는 내 컴퓨터에서 같은 레벨에서 여러 번 수행되는 것을 관찰했으며, FileChannel 방식이 더 느리다는 것을 여러 번 보았습니다. 이 두 가지 방법을 비교하여 자세한 내용을 알고 싶습니까? 여기에 제가 사용한 코드가 있습니다. 제가 테스트하는 파

codeday.me

 

https://stackoverflow.com/questions/19486077/java-fastest-way-to-read-through-text-file-with-2-million-lines

 

Java Fastest way to read through text file with 2 million lines

Currently I am using scanner/filereader and using while hasnextline. I think this method is not highly efficient. Is there any other method to read file with the similar functionality of this? pu...

stackoverflow.com