此令牌错误后预期的标识符

Question

Thread thread1 = new Thread() {
    public void run() {

    }
};

Thread thread2 = new Thread() {
    public void run() {

    }
};

thread1.start();
thread2.start();

How can I get rid out of this error? In the line thread1.start() and thread2.start() I get the same error -> Syntax Error on token start, Identifier expected after this token.

Answer 1

Syntax Error on token start, Identifier expected after this token.

means that you declared these statements:

thread1.start();
thread2.start();

as members of the class.
But these are not valid member declarations.

These don't create any issue as these are valid declarations :

Thread thread1 = new Thread() {
    public void run() {

    }
};

Thread thread2 = new Thread() {
    public void run() {

    }
};

As alternative, you could move the start() invocation statements in an initializer or a method.
Here is a example with an initializer :

public class Foo {

    Thread thread1 = new Thread() {
        public void run() {

        }
    };

    Thread thread2 = new Thread() {
        public void run() {

        }
    };

    {
      thread1.start();
      thread2.start();
    }

}

Or if it makes more sense, you can also change the fields into local variables and declare the whole statements in a method :

public class Foo {

    public void myMethod(){    

       Thread thread1 = new Thread() {
          public void run() {

          }
       };

       Thread thread2 = new Thread() {
         public void run() {

        }
       };

       thread1.start();
       thread2.start();
    }

}

Answer 2

Put it inside the main method. It will work properly if you put it inside

public static void main(String args[]){
   //your code
}