package com.crawler.command; import java.util.List; public class HelpCommand extends BaseCommand { private List commands; public HelpCommand(List commands) { this.commands = commands; } @Override public String getName() { return "help"; } @Override public String getDescription() { return "显示所有可用指令"; } @Override public void execute() { System.out.println("可用指令:"); System.out.println("---------"); for (Command cmd : commands) { System.out.printf("%-8s : %s%n", cmd.getName(), cmd.getDescription()); } } }