Argparse4j

argparse4j 是 Python argparse 命令行解析器的 Java 语言移植版。这个要比spring AspectJ 更简单，更方便实现。

<dependency>
  <groupId>net.sourceforge.argparse4j</groupId>
  <artifactId>argparse4j</artifactId>
  <version>0.3.0</version>
</dependency>

 package Argparse4j;

 import net.sourceforge.argparse4j.ArgumentParsers;
 import net.sourceforge.argparse4j.impl.Arguments;
 import net.sourceforge.argparse4j.inf.ArgumentParser;
 import net.sourceforge.argparse4j.inf.ArgumentParserException;
 import net.sourceforge.argparse4j.inf.Namespace;

 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;

 /**
  * Hello world!
  *
  */
 public class App
 {
     private static interface Accumulate {
         int accumulate(Collection<Integer> ints);
     }

     private static class Sum implements Accumulate {
         @Override
         public int accumulate(Collection<Integer> ints) {
             int sum = 0;
             for (Integer i : ints) {
                 sum += i;
             }
             return sum;
         }

         @Override
         public String toString() {
             return getClass().getSimpleName();
         }
     }

     private static class Max implements Accumulate {
         @Override
         public int accumulate(Collection<Integer> ints) {
             return Collections.max(ints);
         }

         @Override
         public String toString() {
             return getClass().getSimpleName();
         }
     }

     public static void main(String[] args) {
         ArgumentParser parser = ArgumentParsers.newArgumentParser("app")
                 .description("Process some integers.");
         parser.addArgument("integers")
                 .metavar("N")
                 .type(Integer.class)
                 .nargs("+")
                 .help("an integer for the accumulator");
         parser.addArgument("--sum")
                 .dest("accumulate")
                 .action(Arguments.storeConst())
                 .setConst(new Sum())
                 .setDefault(new Max())
                 .help("sum the integers (default: find the max)");
         try {
             Namespace res = parser.parseArgs(args);

             System.out.println(res);
             System.out.print("----");
             System.out.println(((Accumulate) res.get("accumulate"))
                     .accumulate((List<Integer>) res.get("integers")));
             System.out.println(res.get("accumulate"));
             System.out.println(res.get("integers"));
         } catch (ArgumentParserException e) {
             parser.handleError(e);
         }
     }

 }

java -jar  com.Argparse4j-1.0-SNAPSHOT.jar 1 X 4 --sum

Namespace(integers=[1, 2, 4], accumulate=Sum)
----7
Sum
[1, 2, 4]

java -jar  com.Argparse4j-1.0-SNAPSHOT.jar 1 3 4

Namespace(integers=[1, 3, 4], accumulate=Max)
----4
Max
[1, 3, 4]