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]);
  }
}