可见性

Kotlin 的可见性与Java的可见性的映射关系如下表所示：

例如下面的Kotlin代码：

class ProgrammingBook {
    private var isbn: String = "978-7-111-44250-9"
    protected var author: String = "Cay"
    public var name: String = "Core Java"
    internal var pages: Int = 300
    private fun findISBN(): String = "978-7-111-44250-9"
    protected fun findAuthor(): String = "Cay"
    public fun findName(): String = "Core Java"
    internal fun findPages(): Int = 300
}

对应的Java的代码是：

public final class ProgrammingBook {
   private String isbn = "978-7-111-44250-9";
   @NotNull
   private String author = "Cay";
   @NotNull
   private String name = "Core Java";
   private int pages = 300;
   @NotNull
   protected final String getAuthor() {
      return this.author;
   }
   protected final void setAuthor(@NotNull String var1) {
      Intrinsics.checkParameterIsNotNull(var1, "<set-?>");
      this.author = var1;
   }
   @NotNull
   public final String getName() {
      return this.name;
   }
   public final void setName(@NotNull String var1) {
      Intrinsics.checkParameterIsNotNull(var1, "<set-?>");
      this.name = var1;
   }
   public final int getPages$production_sources_for_module_chapter10_interoperability_main() {
      return this.pages;
   }
   public final void setPages$production_sources_for_module_chapter10_interoperability_main(int var1) {
      this.pages = var1;
   }
   private final String findISBN() {
      return "978-7-111-44250-9";
   }
   @NotNull
   protected final String findAuthor() {
      return "Cay";
   }
   @NotNull
   public final String findName() {
      return "Core Java";
   }
   public final int findPages$production_sources_for_module_chapter10_interoperability_main() {
      return 300;
   }
}

我们可以看到Kotlin中的可见性跟Java中的基本相同。