使用Apache commons-cli包进行命令行参数解析的示例代码

<dependency>  <groupId>commons-cli</groupId>  <artifactId>commons-cli</artifactId>  <version>1.3.1</version></dependency>

import java.io.File;import java.io.IOException;import java.util.ArrayList;import java.util.Arrays;import java.util.HashSet;​import org.apache.commons.cli.CommandLine;import org.apache.commons.cli.CommandLineParser;import org.apache.commons.cli.DefaultParser;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 com.lwt.util.DirUtil;​public class CommandLineUtil {  private String[] args;  private Options opts = new Options();  private File keyFile;  private boolean encrypt;  private boolean create;  private boolean enName;  private File[] files;  private File[] dirs;  public File getKeyFile() {    return keyFile;  }  public boolean isEncrypt() {    return encrypt;  }  public boolean isEnName() {    return enName;  }  public boolean isCreate() {    return create;  }  public File[] getFiles() {    return files;  }  public File[] getDirs() {    return dirs;  }​  public CommandLineUtil(String[] args) {    this.args = args;    definedOptions();    parseOptions();    duplicate_removal();  }  // 定义命令行参数  private void definedOptions(){    Option opt_h = new Option("h", "Show this page.");    Option opt_e = new Option("e", "encrypt", false, "Encrypt file.");    Option opt_d = new Option("d", "decrypt", false, "Decrypt file.");    Option opt_c = new Option("c", "create", false, "Create new key file.");    Option opt_n = new Option("n", "name", false, "Encrypt file name.");    Option opt_k = Option.builder("k").hasArg().argName("keyFile")        .desc("Specify the key file").build();    Option opt_f = Option.builder("f").hasArgs().argName("file1,file2...")        .valueSeparator(',')        .desc("A files list with ',' separate to handle").build();    Option opt_r = Option        .builder("r")        .hasArgs()        .argName("dir1,dir1...")        .valueSeparator(',')        .desc("A directories list with ',' separate to handle its child files")        .build();    Option opt_R = Option        .builder("R")        .hasArgs()        .argName("dir1,dir1...")        .valueSeparator(',')        .desc("A directories list with ',' separate to recurse handle child files")        .build();    opts.addOption(opt_n);    opts.addOption(opt_c);    opts.addOption(opt_k);    opts.addOption(opt_h);    opts.addOption(opt_e);    opts.addOption(opt_d);    opts.addOption(opt_f);    opts.addOption(opt_r);    opts.addOption(opt_R);  }  // 解析处理命令行参数  private void parseOptions(){    CommandLineParser parser = new DefaultParser();    CommandLine line = null;    // 解析命令行参数    try {      line = parser.parse(opts, args);    } catch (ParseException e) {      System.err.println(e.getMessage());      System.exit(1);    }​    // 若指定h则显示帮助    if (args == null || args.length == 0 || line.hasOption("h")) {      HelpFormatter help = new HelpFormatter();      help.printHelp("encrypt", opts);    }​    // 选择加密或解密操作，默认是加密文件    if (line.hasOption("d")) {      if (line.hasOption("e")) {        System.err            .println("The -e and -d option can't specify at the same time.");        System.exit(1);      }      encrypt = false;    } else {      encrypt = true;      if(line.hasOption("n")){        enName = true;      }    }    if (line.hasOption("k")) {      String k = line.getOptionValue("k");      File file = new File(k);      if (line.hasOption("c")) {        keyFile = file;        create = true;      }else {        if(file.isFile()){          keyFile = file;        } else{          System.err.println(file + " is not a available key file");          System.exit(1);        }      }    }​    ArrayList<File> files = new ArrayList<File>();    ArrayList<File> dirs = new ArrayList<File>();    if (line.hasOption("f")) {      String[] fs = line.getOptionValues("f");      for(String f : fs){        File file = new File(f);        if(file.isFile()){          files.add(file);        }else{          System.err.println(file + " is not a file");          System.exit(1);        }      }    }​    if (line.hasOption("r")) {      String[] rs = line.getOptionValues("r");      for(String r : rs){        File dir = new File(r);        if(dir.isDirectory()){          dirs.add(dir);          DirUtil dirUtil = new DirUtil(dir);          files.addAll(Arrays.asList(dirUtil.getFiles()));          dirs.addAll(Arrays.asList(dirUtil.getDirs()));        }else{          System.err.println(dir + " is not a directory");          System.exit(1);        }      }    }​    if (line.hasOption("R")) {      String[] Rs = line.getOptionValues("R");      for(String R : Rs){        File dir = new File(R);        if(dir.isDirectory()){          dirs.add(dir);          DirUtil dirUtil = new DirUtil(dir);          files.addAll(Arrays.asList(dirUtil.getAllFiles()));          dirs.addAll(Arrays.asList(dirUtil.getAllDirs()));        }else{          System.err.println(dir + " is not a directory");          System.exit(1);        }      }    }    this.files = files.toArray(new File[0]);    this.dirs = dirs.toArray(new File[0]);  }  public void duplicate_removal (){    HashSet<File> fileSet = new HashSet<File>();    for(File file : files){      try {        fileSet.add(file.getCanonicalFile());      } catch (IOException e) {        System.err.println(e.getMessage());        System.exit(1);      }    }    files = fileSet.toArray(new File[0]);    fileSet = new HashSet<File>();    for(File dir : dirs){      try {        fileSet.add(dir.getCanonicalFile());      } catch (IOException e) {        System.err.println(e.getMessage());        System.exit(1);      }    }    dirs = fileSet.toArray(new File[0]);  }}