GAB-CmdLine
The GAB Social Command Line Parser for Java. The purpose of this project is to analyze and examine how I would create a command line parser for Java. Comments are welcome. Thank you.
Required
This project requires the following:
* Java 8 or 11
* Maven
Maven Dependency
<dependency>
<groupId>com.gabstudios</groupId>
<artifactId>gab-cmdline</artifactId>
<version>1.0.0-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>com.gabstudios</groupId>
<artifactId>gab-collection</artifactId>
<version>1.0.0-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>com.gabstudios</groupId>
<artifactId>gab-logging</artifactId>
<version>1.0.0-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>com.gabstudios</groupId>
<artifactId>gab-validate</artifactId>
<version>1.0.0</version>
</dependency>Build
Use Maven to build - mvn package.
Usage
In order to parse the command line, you need to define what the commands are by calling Cmdline.defineCommand("xxx");
CmdLine.defineCommand("-help, #print this message")The string used in the defineCommand() method, contains tokens that must use one of these symbols in order for it to be recognized as that type:
# = The description of the command. There may be zero to one defined.
! = A required value for the command name. There can be zero to many defined.
? = An optional value for the command name. There can be zero to many defined.
: = The regex value to match on for any values that are defined. There can be zero to one defined.
... = A value ends with ... and is a list for the command name. There can be zero to one defined. This can be used with the ! and ? symbols
If a token does not start with one of these tokens, then it is considered a command name. There can be one to many names that represent a single command, such as: 'f', 'file', 'filename' or '-f', '--file', '--filename'.
Example
myApp [commands] [option1 [option2 [option3] ...]]
Commands:
-help print this message
-version print the version information and exit
-quiet be extra quiet
-verbose be extra verbose
-debug print debugging information
-logfile <file> use given file for log
-logger <classname> the class which is to perform logging
-listener <classname> add an instance of class as a project listener
-D<property>=<value> use value for given property
-find <file> search for file towards the root of the
filesystem and use it
// define a listener implementation of the CommandListener interface.
private class CmdLineListener implements CommandListener
{
@Override
public void handle(final Command command)
{
System.out.println( command );
}
}
// create an instance of the listener.
final CmdLineListener listener = new CmdLineListener();
// define/declare the commands the parser should parse.
// command names can start with any character that is not reserved. reserved are !?#:
// the commands listed below use the - (dash) to denote a command, but this is not required.
CmdLine.defineCommand("-help, #print this message")
.defineCommand("-version, #print the version information and exit")
.defineCommand("-quiet, #be extra quiet")
.defineCommand("-verbose, #be extra verbose")
.defineCommand("-debug, #print debugging information")
.defineCommand("-logfile, !logFile, #use given file for log")
.defineCommand("-logger, !logClass, #the class which is to perform logging")
.defineCommand("-listener, !listenerClass, #add an instance of class as a project listener")
.defineCommand("-find, !buildFile, #search for file towards the root of the file system and use it");
Note: The format of "-D<property>=<value>" is automatically supported and doesnt need to be defined.
If a -D<property>=<value> is seen on the command line, it is parsed and set
in the System properties. In addition, a command is created and sent to the listener.
// parse the command line args and pass matching commands to the listener for processing.
final List<command> = CmdLine.parse( args, listener );Click for more examples.
More Documentation
Check the project wiki.
Copyright
[Copyright 2016 Gregory Brown]
License
This codebase is licensed under the Apache v2.0 License.
Feedback
Comments and feedback are greatly appreciated!!!