Grep Class Reference

Collaboration diagram for Grep:

Static Public Member Functions
static void	main (String[] args) throws IOException

Static Private Member Functions
static Stream< Path >	getPathStream (Path path)
static Stream< String >	path2Lines (Path path)
static void	printUsageAndExit (String... str)

Detailed Description

Grep prints lines matching a regex. See printUsageAndExit(String...) method for instructions and command line parameters. This sample shows examples of using next features:

• Lambda and bulk operations. Working with streams: map(...),filter(...),flatMap(...),limit(...) methods.
• Static method reference for printing values.
• New Collections API forEach(...) method.
• Try-with-resources feature.
• new Files.walk(...), Files.lines(...) API.
• Streams that need to be closed.

Definition at line 67 of file Grep.java.

Member Function Documentation

getPathStream()

static Stream<Path> Grep.getPathStream ( Path  path )

staticprivate

Flattens file system hierarchy into a stream. This code is not inlined for the reason of Files.walk() throwing a checked IOException that must be caught.

Parameters

path	- the file or directory

Returns

Whole file tree starting from path, a stream with one element - the path itself - if it is a file.

Definition at line 162 of file Grep.java.

References path.

Referenced by main().

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main()

static void Grep.main ( String[]  args ) throws IOException

static

The main method for the Grep program. Run program with empty argument list to see possible arguments.

Parameters

args	the argument list for Grep.

Exceptions

java.io.IOException

If an I/O error occurs.

Definition at line 89 of file Grep.java.

References getPathStream(), path2Lines(), and printUsageAndExit().

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path2Lines()

static Stream<String> Grep.path2Lines ( Path  path )

staticprivate

Produces a stream of lines from a file. The result is a stream in order to close it later. This code is not inlined for the reason of Files.lines() throwing a checked IOException that must be caught.

Parameters

path	- the file to read

Returns

stream of lines from the file

Definition at line 178 of file Grep.java.

References path.

Referenced by main().

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printUsageAndExit()

static void Grep.printUsageAndExit ( String...  str )

staticprivate

Definition at line 69 of file Grep.java.

Referenced by main().

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The documentation for this class was generated from the following file:

• build/windows-installer/unpacked/java-se-8u41-ri/sample/lambda/BulkDataOperations/src/Grep.java