This is first time am using apache commons-cli.
Requirement : i want to use CommandLine and Options in commons-cli to pass my runtime parameters to my java class.
Scenario : main class - com.test.mian.MyClass
i can run my class from command line by
java -cp $classPath com.test.mian.MyClass -one 1 -two 2 -three 3
how can i do the same from a method of another class by passing these arguments using CommandLine and Options of commons-cli.
and also if there is any other way other than
System.setProperty("key","value");
please suggest too.
Here's a very stripped down version of something I use. It basically sets up a singleton that gets initialized once and then can be used wherever you want within your program. I chose to store the info in HashMap's and ArrayList's because they were easier to deal with later.
//****************************************************************************
//***** File Name: MianCLIOptions.java
//****************************************************************************
package com.test.mian;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.commons.cli.AlreadySelectedException;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.GnuParser;
import org.apache.commons.cli.MissingArgumentException;
import org.apache.commons.cli.MissingOptionException;
import org.apache.commons.cli.Option;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.ParseException;
import org.apache.commons.cli.UnrecognizedOptionException;
import org.apache.commons.lang.WordUtils;
//****************************************************************************
//****************************************************************************
//****************************************************************************
//****************************************************************************
public class MianCLIOptions
{
//***** constants *****
//***** public data members *****
//***** private data members *****
private static MianCLIOptions singletonObj = null;
private HashMap<String,Object> options = new HashMap<String,Object>();
private ArrayList<String> arguments = new ArrayList<String>();
//****************************************************************************
public static MianCLIOptions getopts()
{
if (singletonObj == null) {
throw new IllegalStateException("[MianCLIOptions] Command line not yet initialized.");
}
return singletonObj;
}
//****************************************************************************
public static synchronized void initialize(Options optsdef, String[] args)
throws MianCLIOptionsException, UnrecognizedOptionException, MissingArgumentException,
MissingOptionException, AlreadySelectedException, ParseException
{
if (singletonObj == null) {
singletonObj = new MianCLIOptions(optsdef, args);
}
else {
throw new IllegalStateException("[MianCLIOptions] Command line already initialized.");
}
}
//****************************************************************************
//----- prevent cloning -----
public Object clone() throws CloneNotSupportedException
{
throw new CloneNotSupportedException();
}
//****************************************************************************
public boolean isset(String opt)
{
return options.containsKey(opt);
}
//****************************************************************************
public Object getopt(String opt)
{
Object rc = null;
if (options.containsKey(opt)) {
rc = options.get(opt);
}
return rc;
}
//****************************************************************************
//***** finally parse the command line
//****************************************************************************
private MianCLIOptions(Options optsdef, String[] args)
throws UnrecognizedOptionException, MissingArgumentException,
MissingOptionException, AlreadySelectedException, ParseException
{
//***** (blindly) parse the command line *****
CommandLineParser parser = new GnuParser();
CommandLine cmdline = parser.parse(optsdef, args);
//***** store options and arguments *****
//----- options -----
for (Option opt : cmdline.getOptions()) {
String key = opt.getOpt();
if (opt.hasArgs()) {
options.put(key, opt.getValuesList());
}
else {
options.put(key, opt.getValue());
}
}
//----- arguments -----
for (String str : cmdline.getArgs()) {
//----- account for ant/build.xml/generic -----
if (str.length() > 0) {
arguments.add(str);
}
}
}
}
//****************************************************************************
//***** EOF ***** EOF ***** EOF ***** EOF ***** EOF ***** EOF **********
In your main, you can then call it like so:
//***** build up options *****
Options options = new Options();
// ... .... ...
//***** process command line *****
try {
MianCLIOptions.initialize(options, args);
}
catch (UnrecognizedOptionException ex) {
// do something
}
And finally, in some other class you can call it like so:
MianCLIOptions opts = MianCLIOptions.getopts();
if (opts.isset("someopt")) {
// do something exciting
}
Hope that helps!