面试官：来说说Tomcat的启动过程是什么样子的

  public static void main(String[] args) {
//对象初始化
if (daemon == null) {
Bootstrap bootstrap = new Bootstrap();
try {
bootstrap.init();
} catch (Throwable var3) {
handleThrowable(var3);
var3.printStackTrace();
return;
}
daemon = bootstrap;
} else {
Thread.currentThread().setContextClassLoader(daemon.catalinaLoader);
}
try {
String command = "start";
if (args.length > 0) {
command = args[args.length - 1];
}
if (command.equals("startd")) {
args[args.length - 1] = "start";
//加载
daemon.load(args);
//启动
daemon.start();
} else if (command.equals("stopd")) {
args[args.length - 1] = "stop";
//停止
daemon.stop();
} else if (command.equals("start")) {
daemon.setAwait(true);
//加载并且启动
daemon.load(args);
daemon.start();
if (null == daemon.getServer()) {
System.exit(1);
}
} else if (command.equals("stop")) {
daemon.stopServer(args);
} else if (command.equals("configtest")) {
daemon.load(args);
if (null == daemon.getServer()) {
System.exit(1);
}
System.exit(0);
} else {
log.warn("Bootstrap: command \"" + command + "\" does not exist.");
}
} catch (Throwable var4) {
Throwable t = var4;
if (var4 instanceof InvocationTargetException && var4.getCause() != null) {
t = var4.getCause();
}
handleThrowable(t);
t.printStackTrace();
System.exit(1);
}
}

  Bootstrap bootstrap = new Bootstrap();
try {
bootstrap.init();
} catch (Throwable var3) {

 public void start() throws Exception {
if (this.catalinaDaemon == null) {
this.init();
}
Method method = this.catalinaDaemon.getClass().getMethod("start", (Class[])null);
method.invoke(this.catalinaDaemon, (Object[])null);
}

if (!this.loaded) {
this.loaded = true;
long t1 = System.nanoTime();
try {
inputSource.setByteStream((InputStream)inputStream);
digester.push(this);
digester.parse(inputSource);
break label242;
} catch (SAXParseException var28) {
log.warn("Catalina.start using " + this.getConfigFile() + ": " + var28.getMessage());
return;
} catch (Exception var29) {
log.warn("Catalina.start using " + this.getConfigFile() + ": ", var29);
}
} finally {
if (inputStream != null) {
try {
((InputStream)inputStream).close();
} catch (IOException var23) {
;
}
}
}
return;
}
try {
//此处同样调用的Server的init方法，
this.getServer().init();
} catch (LifecycleException var24) {
if (Boolean.getBoolean("org.apache.catalina.startup.EXIT_ON_INIT_FAILURE")) {
throw new Error(var24);
}
log.error("Catalina.start", var24);
}
long t2 = System.nanoTime();
if (log.isInfoEnabled()) {
log.info("Initialization processed in " + (t2 - t1) / 1000000L + " ms");
}
}

public abstract class LifecycleMBeanBase extends LifecycleBase implements JmxEnabled {

public abstract class LifecycleBase implements Lifecycle {

 protected void startInternal() throws LifecycleException {
this.fireLifecycleEvent("configure_start", (Object)null);
this.setState(LifecycleState.STARTING);
this.globalNamingResources.start();
Object var1 = this.servicesLock;
synchronized(this.servicesLock) {
for(int i = 0; i < this.services.length; ++i) {
this.services[i].start();
}
}
}

public void addService(Service service) {
service.setServer(this);
Object var2 = this.servicesLock;
synchronized(this.servicesLock) {
Service[] results = new Service[this.services.length + 1];
System.arraycopy(this.services, 0, results, 0, this.services.length);
results[this.services.length] = service;
this.services = results;
if (this.getState().isAvailable()) {
try {
service.start();
} catch (LifecycleException var6) {
;
}
}
this.support.firePropertyChange("service", (Object)null, service);
}
}

  protected void initInternal() throws LifecycleException {
super.initInternal();
if (this.engine != null) {
this.engine.init();
}
Executor[] arr$ = this.findExecutors();
int len$ = arr$.length;
int len$;
for(len$ = 0; len$ < len$; ++len$) {
Executor executor = arr$[len$];
if (executor instanceof JmxEnabled) {
((JmxEnabled)executor).setDomain(this.getDomain());
}
executor.init();
}
this.mapperListener.init();
Object var11 = this.connectorsLock;
synchronized(this.connectorsLock) {
Connector[] arr$ = this.connectors;
len$ = arr$.length;
for(int i$ = 0; i$ < len$; ++i$) {
Connector connector = arr$[i$];
try {
connector.init();
} catch (Exception var9) {
String message = sm.getString("standardService.connector.initFailed", new Object[]{connector});
log.error(message, var9);
if (Boolean.getBoolean("org.apache.catalina.startup.EXIT_ON_INIT_FAILURE")) {
throw new LifecycleException(message);
}
}
}
}
}