CommandBase.java

package org.cryptocoinpartners.command;

import org.apache.commons.lang.StringUtils;
import org.cryptocoinpartners.module.Context;
import org.cryptocoinpartners.util.Injector;
import org.cryptocoinpartners.util.ReflectionUtil;
import org.reflections.Reflections;

import javax.inject.Inject;
import java.lang.reflect.Modifier;
import java.util.*;


/**
 * @author Tim Olson
 */
public abstract class CommandBase implements Command {

    @Override
    public String getUsageHelp() { return StringUtils.join(getCommandNames(getClass()),"|"); }

    @Override
    public void parse(String commandArguments) { }


    // these 2 are injected by ConsoleRunMode
    @Inject
    protected Context context;
    @Inject
    protected ConsoleWriter out;
    @Inject
    protected Injector injector;


    public static List<String> allCommandNames() {
        ArrayList<String> names = new ArrayList<>(commandClassesByName.keySet());
        Collections.sort(names);
        return names;
    }


    public static Command commandForName( String name, Context context ) {
        Class<? extends Command> commandClass = commandClassesByName.get(name.toLowerCase());
        if( commandClass == null )
            return null;
        return context.attach(commandClass);
    }


    private static Map<String,Class<? extends Command>> commandClassesByName;


    static {
        commandClassesByName = new HashMap<>();
        Reflections reflections = ReflectionUtil.getCommandReflections();
        Set<Class<? extends Command>> commandClasses = reflections.getSubTypesOf(Command.class);
        for( Class<? extends Command> commandClass : commandClasses ) {
            int modifiers = commandClass.getModifiers();
            if( Modifier.isAbstract(modifiers) || Modifier.isInterface(modifiers) )
                continue;
            for( String commandName : getCommandNames(commandClass) )
                commandClassesByName.put(commandName.toLowerCase(),commandClass);
        }
    }


    private static String[] getCommandNames(Class<? extends Command> commandClass) {
        String[] commandNames;
        String className;
        CommandName commandNameAnn = commandClass.getAnnotation(CommandName.class);
        if( commandNameAnn != null ) {
            commandNames = commandNameAnn.value();
        }
        else {
            className = commandClass.getSimpleName();
            if( !className.endsWith("Command") ) {
                throw new Error("If the name of your subclass of CommandBase doesn't end with \"Command\" then you need to use the @CommandName(name) annotation to declare the name of your command");
            }
            commandNames = new String[]{className.substring(0,className.length() - "Command".length()).toLowerCase()};
        }
        return commandNames;
    }
}