[FIXED] Autowire Enum in Spring Bean

Issue

Iam trying to autowire an enum inside a spring Bean.I have not tried this before and not sure what is missing but when i do that i am getting parameter 0 of constructor in required a bean of type java.lang.string error. Please find below the code i have created.

public interface TokenGenerator{
 String generateToken();
}

@Service
public enum  TokenGeneratorImpl implements TokenGenerator{

INSTANCE;

private string token;

public string  generateToken(){
    if(token == null){
      token="new token";
    }

    return token;
   }
}


@Service
public class ConnectionService {

 @Autowired
 private TokenGenerator generator

 public void getConnection(){
   for(int i =0; i< 1000; i++){
         Thread t = new Thread(() -> generator.generateToken());
          t.start();
      }
   }
 }

There are two issues: 1) Autowiring is not working and I am getting

parameter 0 of constructor in required a bean of type java.lang.string error

2) If i call directly the Enum and generate the token then i found that this code is not thread safe and want to understand how I can make it thread safe

Solution

By autowiring the TokenGeneratorImpl, you are trying to instantiate an ENUM which is not possible

https://stackoverflow.com/a/36710397/5001937

For 2nd Point https://stackoverflow.com/a/2531998/5001937

Answered By - Suraj
Answer Checked By - Robin (JavaFixing Admin)