Kotlin 에서 협 변,역 변 과 변 하지 않 는 예제 에 대한 상세 한 설명

//out    Number  Int   ，          
val numberList:List<Number> = listOf<Int>(1,58)
 public interface List<out E> : Collection<E> {
 // Query Operations
 override val size: Int

 override fun isEmpty(): Boolean
 //         ，          
 override fun contains(element: @UnsafeVariance E): Boolean
 override fun iterator(): Iterator<E>

 // Bulk Operations
 override fun containsAll(elements: Collection<@UnsafeVariance E>): Boolean

 // Positional Access Operations
 /**
  * Returns the element at the specified index in the list.、
         E
  */
 public operator fun get(index: Int): E

 // Search Operations
 /**
  * Returns the index of the first occurrence of the specified element in the list, or -1 if the specified
  * element is not contained in the list.
  */
 public fun indexOf(element: @UnsafeVariance E): Int

 /**
  * Returns the index of the last occurrence of the specified element in the list, or -1 if the specified
  * element is not contained in the list.
  */
 public fun lastIndexOf(element: @UnsafeVariance E): Int

 // List Iterators
 /**
  * Returns a list iterator over the elements in this list (in proper sequence).
  */
 public fun listIterator(): ListIterator<E>

 /**
  * Returns a list iterator over the elements in this list (in proper sequence), starting at the specified [index].
  */
 public fun listIterator(index: Int): ListIterator<E>

 // View
 /**
  * Returns a view of the portion of this list between the specified [fromIndex] (inclusive) and [toIndex] (exclusive).
  * The returned list is backed by this list, so non-structural changes in the returned list are reflected in this list, and vice-versa.
  *
  * Structural changes in the base list make the behavior of the view undefined.
  */
 public fun subList(fromIndex: Int, toIndex: Int): List<E>
}

  //in    ，                       Any Int   
 val intComparable:Comparable<Int> = object :Comparable<Any>{
      override fun compareTo(other: Any): Int {
        return 0
      }
    }

public interface Comparable<in T> {
  public operator fun compareTo(other: T): Int
}

public interface MutableList<E> : List<E>, MutableCollection<E> {
  override fun add(element: E): Boolean
  override fun remove(element: E): Boolean
  override fun addAll(elements: Collection<E>): Boolean
  public fun addAll(index: Int, elements: Collection<E>): Boolean
  override fun removeAll(elements: Collection<E>): Boolean
  override fun retainAll(elements: Collection<E>): Boolean
  override fun clear(): Unit
  public operator fun set(index: Int, element: E): E
  public fun add(index: Int, element: E): Unit
  public fun removeAt(index: Int): E
  override fun listIterator(): MutableListIterator<E>
  override fun listIterator(index: Int): MutableListIterator<E>
  override fun subList(fromIndex: Int, toIndex: Int): MutableList<E>
}

 //out    Number  Int   ，          
    val numberList:List<*> = listOf<Int>(1,58)
    val any = numberList[1] //   ，    
    //in    ，                      
    val intComparable:Comparable<*> = object :Comparable<Any>{
      override fun compareTo(other: Any): Int {
        return 0
      }
    }
    //   ，     Nothing
    intComparable.compareTo()

fun <T> hello(){

}
open class Hello<T>{

}
//           
class Hello33<T>
//          
class Hello2:Hello<Hello<*>>()
class Hello332:Hello<Hello33<*>>()

    //          
 val raw:Raw<*> = Raw.getRaw()
public class Raw<T> {
  @Override
  public String toString() {
    return "   Raw";
  }
  public static Raw getRaw(){
    return new Raw();
  }
}

    //    ，         ，                
//    val list1:MutableList<Number> = mutableListOf<Int>(1,5,4)
    list1.add(BigDecimal(1244444444))
//    val list2:MutableList<Int> = mutableListOf<Number>(1,5,4)

    //           
//    val numberList11d:List<*> = listOf<*>(1,58)
//
//    hello<*>()
//
//    val hello: Any = Hello<*>()
fun <T> hello(){

}
open class Hello<T>{

}

package com.kotlin.demo.star_demo
import org.jetbrains.annotations.NotNull
import java.lang.reflect.ParameterizedType

/**
 * author： Created by shiming on 2018/4/14 15:08
 * mailbox：[email protected]
 */
//Mvp   V      
interface IView<out P:Ipresenter<IView<P>>>{
  val presenter:P
}
//P      
interface Ipresenter<out V:IView<Ipresenter<V>>>{
//  @NotNull
//  IView getView();
  val view:V
}

abstract class BaseView<out P:BasePresenter<BaseView<P>>>:IView<P>{
  override val presenter:P

  init {
    presenter= findPresenterClass().newInstance()
    presenter.view=this
  }

  /**
   *       Class   
   */
  private fun findPresenterClass():Class<P>{
    //   ，             Class thisClass = this.getClass();
    var thisClass:Class<*> = this.javaClass
//    while(true) {
//      Type var10000 = thisClass.getGenericSuperclass();
//      if(!(var10000 instanceof ParameterizedType)) {
//        var10000 = null;
//      }
//      ParameterizedType var5 = (ParameterizedType)var10000;
//      if(var5 != null) {
//        Type[] var6 = var5.getActualTypeArguments();
//        if(var6 != null) {
//          var10000 = (Type)ArraysKt.firstOrNull((Object[])var6);
//          if(var10000 != null) {
//            Type var2 = var10000;
//            if(var2 == null) {
//              throw new TypeCastException("null cannot be cast to non-null type java.lang.Class<P>");
//            }
//
//            return (Class)var2;
//          }
//        }
//      }
//    }
    //             
    while (true){
      (thisClass.genericSuperclass as? ParameterizedType)
          ?.actualTypeArguments
          ?.firstOrNull()
          ?.let {
            return it as Class<P>
          }?.run{
              thisClass=thisClass.superclass ?:throw IllegalAccessException()
            }
          }
    }

  }


abstract class BasePresenter<out V:IView<BasePresenter<V>>>:Ipresenter<V>{
  //lateinit      
  //@UnsafeVariance                
  override lateinit var view:@UnsafeVariance V
}

class MainView:BaseView<MainPresenter>()

class MainPresenter:BasePresenter<MainView>()

class Mvp{
  init {
    MainView().presenter.let(::println)
    //        
//    BasePresenter var1 = (new MainView()).getPresenter();
//    System.out.println(var1);
    MainView().presenter.let { println("shiming P="+it) }
    //        
//    var1 = (new MainView()).getPresenter();
//    MainPresenter it = (MainPresenter)var1;
//    String var3 = "shiming P=" + it;
//    System.out.println(var3);
//    (new MainPresenter()).getView();

  }
}