在Java中解析命令行参数的好方法是什么?


当前回答

For Spring users, we should mention also https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/core/env/SimpleCommandLinePropertySource.html and his twin brother https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/core/env/JOptCommandLinePropertySource.html (JOpt implementation of the same functionality). The advantage in Spring is that you can directly bind the command line arguments to attributes, there is an example here https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/core/env/CommandLinePropertySource.html

其他回答

如果您想要一些轻量级的(jar大小~ 20 kb)并且使用简单的东西,您可以尝试参数解析器。它可以在大多数用例中使用,支持在参数中指定数组,并且不依赖于任何其他库。它适用于Java 1.5或更高版本。下面摘录了一个如何使用它的例子:

public static void main(String[] args) {
    String usage = "--day|-d day --mon|-m month [--year|-y year][--dir|-ds directoriesToSearch]";
    ArgumentParser argParser = new ArgumentParser(usage, InputData.class);
    InputData inputData = (InputData) argParser.parse(args);
    showData(inputData);

    new StatsGenerator().generateStats(inputData);
}

更多的例子可以在这里找到

Argparse4j是我发现的最好的。它模仿Python的argparse库,非常方便和强大。

看看这些:

http://commons.apache.org/cli/ http://www.martiansoftware.com/jsap/

或者自己卷:

http://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html


例如,这是你如何使用common -cli来解析2个字符串参数:

import org.apache.commons.cli.*;

public class Main {


    public static void main(String[] args) throws Exception {

        Options options = new Options();

        Option input = new Option("i", "input", true, "input file path");
        input.setRequired(true);
        options.addOption(input);

        Option output = new Option("o", "output", true, "output file");
        output.setRequired(true);
        options.addOption(output);

        CommandLineParser parser = new DefaultParser();
        HelpFormatter formatter = new HelpFormatter();
        CommandLine cmd = null;//not a good practice, it serves it purpose 

        try {
            cmd = parser.parse(options, args);
        } catch (ParseException e) {
            System.out.println(e.getMessage());
            formatter.printHelp("utility-name", options);

            System.exit(1);
        }

        String inputFilePath = cmd.getOptionValue("input");
        String outputFilePath = cmd.getOptionValue("output");

        System.out.println(inputFilePath);
        System.out.println(outputFilePath);

    }

}

命令行用法:

$> java -jar target/my-utility.jar -i asd                                                                                       
Missing required option: o

usage: utility-name
 -i,--input <arg>    input file path
 -o,--output <arg>   output file

For Spring users, we should mention also https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/core/env/SimpleCommandLinePropertySource.html and his twin brother https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/core/env/JOptCommandLinePropertySource.html (JOpt implementation of the same functionality). The advantage in Spring is that you can directly bind the command line arguments to attributes, there is an example here https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/core/env/CommandLinePropertySource.html

我想向您展示我的实现:ReadyCLI

优点:

for lazy programmers: a very small number of classes to learn, just see the two small examples on the README in the repository and you are already at 90% of learning; just start coding your CLI/Parser without any other knowledge; ReadyCLI allows coding CLIs in the most natural way; it is designed with Developer Experience in mind; it largely uses the Builder design pattern and functional interfaces for Lambda Expressions, to allow a very quick coding; it supports Options, Flags and Sub-Commands; it allows to parse arguments from command-line and to build more complex and interactive CLIs; a CLI can be started on Standard I/O just as easily as on any other I/O interface, such as sockets; it gives great support for documentation of commands.

我开发这个项目是因为我需要新的功能(选项,标志,子命令),并且可以在我的项目中以最简单的方式使用。