Spring Boot- Autowiring interface implemented by different beans - spring

Question

I have multiple beans with #Component implementing a generic interface.
I have a class where I use methods from these beans. Instead of autowiring each bean separately, I was figuring out of autowiring the interface as a list.
But how do I call the methods of different beans when I just autowire the interface.
public interface Generic {
}
#Component
public class A implements Generic{
.....
public void test{
}
}
#Component
public class B implements Generic{
.....
public void read{}
}
#component class C {
#Autowired
List <Generic> mylist; // type of list is Generic
Now I need to access read from B and test from A

Answer 1

With your new question you CAN do it like this way but I think it's better to use 2 seperate lists instead of the instanceOf.
public interface Generic { }
public interface GenericTestable extends Generic {
void test()
}
public interface GenericReader extends Generic {
void read()
}
#Component
public class A implements GenericTestable {
public void test() { }
}
#Component
public class B implements GenericReader {
public void read() { }
}
#Component
public class C {
private final List<Generic> genericItems;
#Autowired
public C(List<Generic> genericItems) {
this.genericItems = genericItems;
}
public void callThem() {
this.genericItems.forEach(this::callMethodOnSpecificType);
}
private void callMethodOnSpecificType(Generic genericItem) {
if (genericItem instanceof GenericTestable) {
((GenericTestable) genericItem).test();
} else if (genericItem instanceof GenericReader) {
((GenericReader) genericItem).read();
}
}
}
But I think that something like this is a better approach. Cleaner and faster code. Remove the Generic interface and use only the 2 separate interfaces.
public class BetterC {
private final List<GenericTestable> genericTestables;
private final List<GenericReader> genericReaders;
#Autowired
public BetterC(List<GenericTestable> genericTestables, List<GenericReader> genericReaders) {
this.genericTestables = genericTestables;
this.genericReaders = genericReaders;
}
public void callTestables() {
this.genericTestables.forEach(GenericTestable::test);
}
public void callReaders() {
this.genericReaders.forEach(GenericReader::read);
}
}

Answer 2

How about using the Generic interface to route the call ?
From the java-doc api : Ordered
Ordered is an interface that can be implemented by objects that should
be orderable, for example in a Collection. The actual order can be
interpreted as prioritization, with the first object (with the lowest
order value) having the highest priority.
import org.springframework.core.Ordered;
public interface Generic extends Ordered {
void call();
}
----
#Component
public class A implements Generic {
#Override
public int getOrder() {
return 2;
}
#Override
public void call() {
test();
}
public void test() {
System.out.println("Call test()");
}
}
----
#Component
public class B implements Generic {
#Override
public int getOrder() {
return 1;
}
#Override
public void call() {
read();
}
public void read() {
System.out.println("call read()");
}
}
----
#Component
public class C {
List<Generic> list;
public C(List<Generic> list) {
this.list = list;
}
public void testMethod() {
for(Generic g: list) {
g.call();
}
}
}

Answer 3

try this in your implementation
#Component
#Qualifer("a")
public class A implements Generic{ ..... public void test(){ }}
#Component
#Qualifer("b")
public class B implements Generic{ ..... public void read(){ }}
#component
public class C {
#Autowired
Generic a;
#Autowired
Generic b;
... call respective methods
}