我必须将专有的Java API包装成更有用的东西。中央类是"客户端"对象签名就是这样:
public class ProprietaryClient {
private final IEvents eventHandler;
private Object one;
private Object two;
public ProprietaryClient(ProprietaryClient.IEvents eventHandler){
this.eventHandler = eventHandler;
}
//returns immediately
public void connect(String url){
//doing nasty stuff that triigers
//on success
//will be called from somewhere at anytime
// eventHandler.onStateChange( State.CONNECTED );
}
//returns immediately
public void login(String user, String password){
//doing nasty stuff that sets fields one and two
//will be called from somewhere at anytime
//eventHandler.onStateChange( State.LOGGED_IN );
//eventHandler.onLogin( one, two );
}
public interface IEvents {
void onStateChange(State state);
void onLogin(Object one, Object two);
}
public enum State{
CONNECTED,
LOGGED_IN,
UNKNOWN;
}
}
此对象仅在状态" logged_in"中有用,但是该字段没有得到的。知道对象是否可用的唯一方法是:
- 呼叫连接
- 等待状态更改连接
- 致电登录
- 等待状态更改为logged_in(或Onlogin的呼吁(
我想将其包装成一个类,该类可在构造函数中连接和登录,并告诉用户是否准备就绪。我的想法是拥有一种返回完整未来或将来的方法:这就是我到目前为止的。事件的内容正在以这种方式工作。IEVENT的实现将所有EVANT都包含在用户识别的消息中(此部分正在起作用(。但是如何根据到达事件(带有///的零件???(创建和维护完整的未图有没有办法创建我自己的未来,如果事件到达或满足正确的条件,可以做好准备?
public class MyClient implements Client, MessageHandler {
private final String password;
private final IEvents eventHandler;
private final SubscribableChannel eventBus;
private final String user;
private final ProprietaryClient propClient;
public SikomClient( String user, String password, IEvents eventHandler, SubscribableChannel eventBus) {
this.eventHandler = checkNotNull( eventHandler );
this.eventBus = checkNotNull( eventBus );
eventBus.subscribe( this );
this.password = password;
this.user = user;
propClient = new ProprietaryClient(eventHandler);
///????
propClient.connect("url");
//have to wait until message received and state is "CONNECT"
propClient.login(user, password);
}
public CompletableFuture<Boolean> amIready(){
//???
}
@Override
public void handleMessage( Message<?> message ) throws MessagingException {
if( message instanceof OnClientStateMessage && belongsToMe( message )){
// ????
} else if( message instanceof OnLoginMessage && belongsToMe( message )) {
// ????
//complete CompletableFuture with true
}
}
private boolean belongsToMe(Message<?> message){
return ((AbstractStringJsonMessage) message).getUserId().equals( user );
}
}
或者有更好的方法可以在没有"未来"的情况下解决这个问题。我想给呼叫者责任等待多长时间,但我的班级应该维护状态并了解它。
解决方案很简单。现在我更好地了解"完整的未来"。
我添加了一个登录方法,一个具有可完整的未来的字段a Getter:
private CompletableFuture<ReturnCode> loggedIn = new CompletableFuture<>();
...
private void login() {
//as per sikom settings each user gets a fixed workplace identified by user name
if( loggedIn.isDone() ) {
loggedIn = new CompletableFuture<>();
}
propClient.login( user, user, password, 0 );
}
public CompletableFuture<ReturnCode> loggedIn() {
return loggedIn;
}
我的处理方法是这样做的:
public void handleMessage( Message<?> message ) throws MessagingException {
if( message instanceof OnClientStateMessage && belongsToMe( message ) ) {
state = ( (OnClientStateMessage) message ).getState();
if( state.equals( ClientState.CONNECT ) ) {
login();
}
} else if( message instanceof OnLoginMessage && belongsToMe( message ) ) {
ReturnCode rc = ( (OnLoginMessage) message ).getRc();
loggedIn.complete( rc );
}
}
我只是手动手动完成未来(由于没有任何任务附件,因此永远不会返回(。
该类的用户将实例化,并可以立即致电loggedin。Calle可以决定等待多长时间才能loggedin.get((。
不知道这是一个好主意:班级它可以扩展完整的future并可以完成自己?!