Java命令行参数类 Commons CLI使用

一、介绍

Commons CLI库是apache的一个子项目，比较起来，其使用方法相对规范。
http://commons.apache.org/proper/commons-cli/

Commons CLI supports different types of options:POSIX like options (ie. tar -zxvf foo.tar.gz)GNU like long options (ie. du --human-readable --max-depth=1)Java like properties (ie. java -Djava.awt.headless=true -Djava.net.useSystemProxies=true Foo)Short options with value attached (ie. gcc -O2 foo.c)long options with single hyphen (ie. ant -projecthelp)A typical help message displayed by Commons CLI looks like this:usage: ls -A,--almost-all          do not list implied . and .. -a,--all                 do not hide entries starting with . -B,--ignore-backups      do not list implied entried ending with ~ -b,--escape              print octal escapes for nongraphic characters    --block-size <SIZE>   use SIZE-byte blocks -c                       with -lt: sort by, and show, ctime (time of last                          modification of file status information) with                          -l:show ctime and sort by name otherwise: sort                          by ctime -C                       list entries by columns

二、例子

package Test;import org.apache.commons.cli.BasicParser;import org.apache.commons.cli.CommandLine;import org.apache.commons.cli.CommandLineParser;import org.apache.commons.cli.GnuParser;import org.apache.commons.cli.HelpFormatter;import org.apache.commons.cli.Option;import org.apache.commons.cli.Options;import org.apache.commons.cli.ParseException;import org.apache.commons.cli.PosixParser;public class CLITest {    public static void main(String[] args) throws ParseException {          Options options = new Options();          //短选项，长选项，选项后是否有参数，描述          Option option = new Option("n", "name", true, "the name of this agent");          option.setRequired(true);//必须设置          options.addOption(option);          option = new Option("f", "conf-file", true,              "specify a config file (required if -z missing)");          option.setRequired(false);          options.addOption(option);          option = new Option("h", "help", false, "display help text");          options.addOption(option);          //CommandLineParser parser = new PosixParser();//Posix风格          CommandLineParser parser = new GnuParser();//gun风格          CommandLine commandLine = parser.parse(options, args);         //判断          if (commandLine.hasOption('h')) {            //格式化输出            new HelpFormatter().printHelp("flume-ng agent", options, true);            return;          }          if (commandLine.hasOption('f')) {          //获取参数          String file = commandLine.getOptionValue('f');          }    }}