CODEWITHSUNDEEP
springspring-mvc
Alex
Alex

Reputation: 2125

Is @Autowired referred to only one object?

In Spring is the @Autowired annotation referred to only one object?

@Autowired
A object_a;

@Autowired
B object_b;

@Autowired
C object_c;

and

@Autowired
A object_a;
B object_b;
C object_c;

Are they the same thing?Thanks

Upvotes: 2

Views: 955

Answers (3)

merours
merours

Reputation: 4106

@Autowire (like any annotation) is specific to the next statement. As a consequence, your examples are not the same.

The Autowired interface may be applied to a constructor, a field or a method :

@Target(value={CONSTRUCTOR,FIELD,METHOD})

Regarding the example you gave in comment :

@Autowired A a, B b, C c;

If a, b and c are fields, it won't compile, since you only have one field declaration per statement.

If they are not, it won't work either since they won't belong to the authorized types.

Upvotes: 2

Anders R. Bystrup
Anders R. Bystrup

Reputation: 16060

No they're not the same. The FieldDeclaration is terminated with the semicolon, as per JLS section 8.3. You could write

@AutoWired A a, b, c;

and have autowiring apply to all three, but that would probably not make much sense, since you can have only on type per field declaration...

Cheers,

Upvotes: 0

Master Slave
Master Slave

Reputation: 28569

In the context of your question the @Autowired refers to only one object. Your later statement will only autowire object_a;

Marks a constructor, field, setter method or config method as to be autowired by Spring's dependency injection facilities.

Used in the way you explained, its a field-level annotation, applying to one field only

Note that if you use the @Autowire on a constructor in spring, you can inject multiple dependencies, as an example

@Autowired
public YourClass(A object_a, B object_b, C object_c) {
  this.object_a = object_a;
  this.object_b = object_b;
  this.object_c = object_c;
}

Upvotes: 4

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