1 /* 2 * Copyright (C) 2019 The Dagger Authors. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package dagger.example.atm; 18 19 import dagger.example.atm.Command.Result; 20 import dagger.example.atm.Command.Status; 21 import java.util.Arrays; 22 import java.util.List; 23 import java.util.Map; 24 import javax.inject.Inject; 25 26 /** Routes individual text commands to the appropriate {@link Command}(s). */ 27 final class CommandRouter { 28 private final Map<String, Command> commands; 29 private final Outputter outputter; 30 31 @Inject CommandRouter(Map<String, Command> commands, Outputter outputter)32 CommandRouter(Map<String, Command> commands, Outputter outputter) { 33 this.commands = commands; 34 this.outputter = outputter; 35 } 36 37 /** 38 * Calls {@link Command#handleInput(String) command.handleInput(input)} on this router's 39 * {@linkplain #commands commands}. 40 */ route(String input)41 Result route(String input) { 42 List<String> splitInput = split(input); 43 if (splitInput.isEmpty()) { 44 return invalidCommand(input); 45 } 46 47 String commandKey = splitInput.get(0); 48 Command command = commands.get(commandKey); 49 if (command == null) { 50 return invalidCommand(input); 51 } 52 53 List<String> args = splitInput.subList(1, splitInput.size()); 54 Result result = command.handleInput(args); 55 return result.status().equals(Status.INVALID) ? invalidCommand(input) : result; 56 } 57 invalidCommand(String input)58 private Result invalidCommand(String input) { 59 outputter.output(String.format("couldn't understand \"%s\". please try again.", input)); 60 return Result.invalid(); 61 } 62 split(String input)63 private static List<String> split(String input) { 64 return Arrays.asList(input.trim().split("\\s+")); 65 } 66 } 67