/*
* Copyright 2014 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.yarn.boot.cli.shell;
import java.io.IOException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import jline.console.ConsoleReader;
import jline.console.completer.CandidateListCompletionHandler;
import org.fusesource.jansi.AnsiRenderer.Code;
import org.springframework.boot.cli.command.Command;
import org.springframework.boot.cli.command.CommandRunner;
import org.springframework.boot.cli.command.core.HelpCommand;
import org.springframework.boot.loader.tools.SignalUtils;
import org.springframework.util.StringUtils;
/**
* A shell for Spring YARN Cli. Drops the user into an event loop (REPL) where command line
* completion and history are available without relying on OS shell features.
*
* @author Jon Brisbin
* @author Dave Syer
* @author Phillip Webb
* @author Janne Valkealahti
*/
public class Shell {
private final ShellCommandRunner commandRunner;
private final ConsoleReader consoleReader;
private final EscapeAwareWhiteSpaceArgumentDelimiter argumentDelimiter = new EscapeAwareWhiteSpaceArgumentDelimiter();
private final ShellPrompts prompts = new ShellPrompts();
/**
* Create a new {@link Shell} instance.
* @throws IOException
*/
public Shell(List<Command> commands) throws IOException {
attachSignalHandler();
this.consoleReader = new ConsoleReader();
this.commandRunner = createCommandRunner(commands);
initializeConsoleReader();
}
private ShellCommandRunner createCommandRunner(List<Command> commands) {
ShellCommandRunner runner = new ShellCommandRunner();
runner.addCommand(new HelpCommand(runner));
if (commands != null) {
runner.addCommands(commands);
}
runner.addCommand(new PromptCommand(this.prompts));
runner.addCommand(new ClearCommand(this.consoleReader));
runner.addCommand(new ExitCommand());
runner.addAliases("exit", "quit");
runner.addAliases("help", "?");
runner.addAliases("clear", "cls");
return runner;
}
private void initializeConsoleReader() {
this.consoleReader.setHistoryEnabled(true);
this.consoleReader.setBellEnabled(false);
this.consoleReader.setExpandEvents(false);
this.consoleReader.addCompleter(new CommandCompleter(this.consoleReader,
this.argumentDelimiter, this.commandRunner));
this.consoleReader.setCompletionHandler(new CandidateListCompletionHandler());
}
private void attachSignalHandler() {
SignalUtils.attachSignalHandler(new Runnable() {
@Override
public void run() {
handleSigInt();
}
});
}
/**
* Run the shell until the user exists.
* @throws Exception on error
*/
public void run() throws Exception {
printBanner();
try {
runInputLoop();
}
catch (Exception ex) {
if (!(ex instanceof ShellExitException)) {
throw ex;
}
}
}
private void printBanner() {
String version = getClass().getPackage().getImplementationVersion();
version = (version == null ? "" : " (v" + version + ")");
System.out.println(ansi("Spring YARN Cli", Code.BOLD).append(version, Code.FAINT));
System.out.println(ansi("Hit TAB to complete. Type 'help' and hit "
+ "RETURN for help, and 'exit' to quit."));
}
private void runInputLoop() throws Exception {
String line;
while ((line = this.consoleReader.readLine(getPrompt())) != null) {
while (line.endsWith("\\")) {
line = line.substring(0, line.length() - 1);
line += this.consoleReader.readLine("> ");
}
if (StringUtils.hasLength(line)) {
String[] args = this.argumentDelimiter.parseArguments(line);
this.commandRunner.runAndHandleErrors(args);
}
}
}
private String getPrompt() {
String prompt = this.prompts.getPrompt();
return ansi(prompt, Code.FG_BLUE).toString();
}
private AnsiString ansi(String text, Code... codes) {
return new AnsiString(this.consoleReader.getTerminal()).append(text, codes);
}
/**
* Final handle an interrup signal (CTRL-C)
*/
protected void handleSigInt() {
if (this.commandRunner.handleSigInt()) {
return;
}
System.out.println("\nThanks for using Spring Boot");
System.exit(1);
}
/**
* Extension of {@link CommandRunner} to deal with {@link RunProcessCommand}s and
* aliases.
*/
private class ShellCommandRunner extends CommandRunner {
private volatile Command lastCommand;
private final Map<String, String> aliases = new HashMap<String, String>();
public ShellCommandRunner() {
super(null);
}
public void addAliases(String command, String... aliases) {
for (String alias : aliases) {
this.aliases.put(alias, command);
}
}
@Override
public Command findCommand(String name) {
if (name.startsWith("!")) {
return new RunProcessCommand(name.substring(1));
}
if (this.aliases.containsKey(name)) {
name = this.aliases.get(name);
}
return super.findCommand(name);
}
@Override
protected void beforeRun(Command command) {
this.lastCommand = command;
}
@Override
protected void afterRun(Command command) {
}
public boolean handleSigInt() {
Command command = this.lastCommand;
if (command != null && command instanceof RunProcessCommand) {
return ((RunProcessCommand) command).handleSigInt();
}
return false;
}
}
}