Inject services to src/groovy in Grails 3.0.9 - grails

Question

I am trying to create an EndPoint file. So I created a file with name ServerEndPointDemo.groovy
package com.akiong
import grails.util.Environment
import grails.util.Holders
import javax.servlet.ServletContext
import javax.servlet.ServletContextEvent
import javax.servlet.ServletContextListener
import javax.servlet.annotation.WebListener
import javax.websocket.EndpointConfig
import javax.websocket.OnClose
import javax.websocket.OnError
import javax.websocket.OnMessage
import javax.websocket.OnOpen
import javax.websocket.Session
import javax.websocket.server.PathParam
import javax.websocket.server.ServerContainer
import javax.websocket.server.ServerEndpoint
import javax.websocket.EncodeException
import javax.servlet.annotation.WebListener
import java.util.concurrent.CopyOnWriteArraySet
#WebListener
#ServerEndpoint(value="/chat/test/{username}")
public class ServerEndPointDemo implements ServletContextListener {
private static HashMap<String, String> usersMap = new HashMap<String, String>();
private static final Set<ServerEndPointDemo> connections = new CopyOnWriteArraySet<>();
private String username
private Session session
#OnOpen
public void handleOpen(Session session,#PathParam("username") String user){
System.out.println("-------------------------------------");
System.out.println(session.getId() + " has opened a connection");
println "user = "+user
connections.add(this);
this.username = user
this.session = session
addUserToMap(username,session.getId())
try{
def ctx = Holders.applicationContext
chatService = ctx.chatService
}
catch (Exception e){
println "e = "+e
}
}
#OnClose
public void handleClose(Session session){
System.out.println("Session " +session.getId()+" has ended");
}
#OnMessage
public String handleMessage(String message,Session session){
chatService.saveSessionAdminJava(session.getId())
}
#OnError
public void handleError(Throwable t){
println "error ~"
}
private void sendMessageToAll(String message){
println "session.size() = "+sessions.size()
for(Session s : sessions){
try {
s.getBasicRemote().sendText(message);
println "sent to session = "+s.getId()
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
}
`
I tried to use this code for calling a method from service:
try {
def ctx = Holders.applicationContext
chatService = ctx.chatService
} catch (Exception e) {
println "e = " + e
}
This is my service:
package com.akiong.services
import com.akiong.maintenance.Chat
class ChatService {
def serviceMethod() {
}
def saveSessionAdminJava(def sessionJava) {
println "jaln!!!"
def chatInstance = Chat.findByIsAdmin("1")
chatInstance.sessionJava = sessionJava
chatInstance.save(failOnError: true)
}
}
But after I tried to run this code, I'm getting this error:
Error : groovy.lang.MissingPropertyException: No such property: chatService for
class: com.akiong.ServerEndPointDemo
Anyone know how to call a method from service to file in src/groovy?

Answer 1

So here is the problem. The code you written is correct for injecting service:
try {
def ctx = Holders.applicationContext
chatService = ctx.chatService
} catch (Exception e) {
println "e = "+e
}
But the chatService is not defined anywhere in your class. So even if your handleOpen method is invoked there must be MissingPropertyException being thrown but since you have handled the top level Exception class (which should never be encouraged) that exception from your handleOpen method got suppressed.
Now, later in your handleMessage method, the same problem is occurring again of chatService being undefined and hence you are getting the exception you posted in your question.
So, you know the answer now :-) Simply define the chatService in your ServerEndPointDemo class.
Update:
public class ServerEndPointDemo implements ServletContextListener {
private static HashMap<String, String> usersMap = new HashMap<String, String>();
private static final Set<ServerEndPointDemo> connections = new CopyOnWriteArraySet<>();
private String username
private Session session
def chartService // Initialize here
// rest of your code
}

Answer 2

import org.apache.commons.logging.LogFactory;
import org.codehaus.groovy.grails.commons.ApplicationHolder as AH
class MyClass{
private static final log = LogFactory.getLog(this)
def ctx = AH.application.mainContext
def authService=ctx.authService
def method(){
log.debug "into MyClass method"
}
}