Question

Anyway so im trying to make something like a chat program and someone told me to use this code to check for new messages while allowing the user to submit a message:

timer.schedule(new TimerTask() {

  @Override
  public void run() {
     read.readChat(line);
  }
 }, 0, 1000);

 //Wait for user input
 while(true) {
     String bar = scan.next();
 }

Where the read.readChat(line); is the method which displays the messages from another file. Java tells me that read and line both have to be declared as final… I dont understand why especially for the “line” because that’s a variable and I need it to change.

Additionally after I declare them as final I get this error:

unreported exception java.lang.Exception; must be caught or declared to be thrown
                            read.readChat(salt);

What am I doing wrong?

Answer 1

Second error tells you that the method read.readChat(line); throws a checked exception so you have to catch.

You cannot use local variables declared at outer class in the Anonymous inner classes. Make them final or declare them as fields (instance variables).

EDIT:

@Override
public void run() {
  try
   {
    read.readChat(line);
   }catch(Exception ex)
   {
     ex.printStackTrace();
   }
}