Java 7 new IO API – Paths.exists [duplicate]
Files.exists Look in the Files class for the static methods exists() and notExists(). Both take a Path. I guess they decided it made more sense as a static rather than instance method.
nio
Java: Converting String to and from ByteBuffer and associated problems
Check out the CharsetEncoder and CharsetDecoder API descriptions – You should follow a specific sequence of method calls to avoid this problem. For example, for CharsetEncoder: Reset the encoder via the reset method, unless it has not been used before; Invoke the encode method zero or more times, as long as additional input may be … Read more
Java: what exactly is the difference between NIO and NIO.2?
Java started initially by offering the File class, in the java.io package to access file systems. This object represents a file/directory and did allow you to perform some operations such as checking if a file/directory exists, get properties and delete it. It had, though, some shortcomings. To name a few: The File class lacked some … Read more
Java NIO: What does IOException: Broken pipe mean? [duplicate]
What causes a “broken pipe”, and more importantly, is it possible to recover from that state? It is caused by something causing the connection to close. (It is not your application that closed the connection: that would have resulted in a different exception.) It is not possible to recover the connection. You need to open … Read more
Gets byte array from a ByteBuffer in java
Depends what you want to do. If what you want is to retrieve the bytes that are remaining (between position and limit), then what you have will work. You could also just do: ByteBuffer bb =.. byte[] b = new byte[bb.remaining()]; bb.get(b); which is equivalent as per the ByteBuffer javadocs.
ByteBuffer.allocate() vs. ByteBuffer.allocateDirect()
Ron Hitches in his excellent book Java NIO seems to offer what I thought could be a good answer to your question: Operating systems perform I/O operations on memory areas. These memory areas, as far as the operating system is concerned, are contiguous sequences of bytes. It’s no surprise then that only byte buffers are … Read more
Java NIO FileChannel versus FileOutputstream performance / usefulness
My experience with larger files sizes has been that java.nio is faster than java.io. Solidly faster. Like in the >250% range. That said, I am eliminating obvious bottlenecks, which I suggest your micro-benchmark might suffer from. Potential areas for investigating: The buffer size. The algorithm you basically have is copy from disk to buffer copy … Read more
Java: Path vs File
Long story short: java.io.File will most likely never be deprecated / unsupported. That said, java.nio.file.Path is part of the more modern java.nio.file lib, and does everything java.io.File can, but generally in a better way, and more. For new projects, use Path. And if you ever need a File object for legacy, just call Path#toFile() Migrating … Read more
Recursively list files in Java
Java 8 provides a nice stream to process all files in a tree. Files.walk(Paths.get(path)) .filter(Files::isRegularFile) .forEach(System.out::println); This provides a natural way to traverse files. Since it’s a stream you can do all nice stream operations on the result such as limit, grouping, mapping, exit early etc. UPDATE: I might point out there is also Files.find … Read more
Create a Path from String in Java7
You can just use the Paths class: Path path = Paths.get(textPath); … assuming you want to use the default file system, of course.