JDK10新特性之var泛型和多个接口实现方法

public class ArrayList<E> extends AbstractList<E>
 implements List<E>, RandomAccess, Cloneable, java.io.Serializable
public class CopyOnWriteArrayList<E>
 implements List<E>, RandomAccess, Cloneable, java.io.Serializable 

 public Object createList(boolean flag){
 if(flag){
  return new ArrayList<>();
 }else{
  return new CopyOnWriteArrayList<>();
 }
 }

public interface ListInterface<E> 
extends List<E>, RandomAccess, Cloneable, 
java.io.Serializable 
{
}

public <E> ListInterface<E> createListWithInterface(boolean flag)
{
 if(flag){
  return (ListInterface<E>) new ArrayList<E>();
 }else{
  return (ListInterface<E>) new CopyOnWriteArrayList<E>();
 }
 }

public <T extends List<E> & RandomAccess & Cloneable & java.io.Serializable, E> 
T createListWithInterfaceT(boolean flag){
 if(flag){
  return (T) new ArrayList<E>();
 }else{
  return (T) new CopyOnWriteArrayList<E>();
 }
 }

public <T extends List<E> & RandomAccess & Cloneable & java.io.Serializable, E>
 void useGenericityType(){
 VarGenericity varGenericity=new VarGenericity();
 T list=varGenericity.createListWithInterfaceT(true);
 }

public void useVarInGenericityType(){
 VarGenericity varGenericity=new VarGenericity();
 var list=varGenericity.createListWithInterfaceT(true);
 }