inner-classes

I have the nub of the code like this: public class OuterClass { public static InnerClass GetInnerClass() { return new InnerClass() { MyProperty = 1 }; } public class InnerClass { public int MyProperty { get; set; } } } what is the solution to property named MyProperty just be settable from the InnerClass and the OuterClass , and out of these scopes, MyProperty just be readonly There is no protection level for that. internal is the tightest you can use, which is limited to files in the same assembly. If you cannot make it a constructor parameter as has been proposed, you could use an interface:

It might sound like a dumb question, but all anonymous classes must be defined and instantiated within an existing class; therefore, they must be inner classes at the same time. This is quite true. Your anonymus class could not be implemented outside of other classes, as a seperate class, because as it is anonymus you would not be even able to refer to it in any way. Additional information: From JLS: An anonymous class is always an inner class (§8.1.3); it is never static (§8.1.1, §8.5.1). Anonymous classes are types of inner classes. See http://docs.oracle.com/javase/tutorial/java/javaOO

How do you create an inner class object with reflection? Both Inner and Outer classes have default constructors that take no parameters Outer class { Inner class{ } public void createO() { Outer.Inner ob = new Inner ();//that works Inner.class.newInstance(); //<--why does this not compile? } } "If the constructor's declaring class is an inner class in a non-static context, the first argument to the constructor needs to be the enclosing instance; see section 15.9.3 of The Java™ Language Specification ." That means you can never construct an inner class using Class.newInstance ; instead, you

I need to implement custom Enum. It should some class which implements Enum methods like valueOf, values and ordinal without directly extending java.lang.Enum. I have been thinking about creating it in such a way where instead of the String should be some generic type T: public class CustomEnum { private static int size; private static final InnerEnum enumValues; public CustomEnum(){ } public String valueOf(String innerEnum, String name){ if(name.equals(innerEnum)){ return innerEnum; } return null; } public InnerEnum values(){ return enumValues; } public int ordinal(){} public static class

If I do this: object Parent { class Inner extends Testable { type Self <: Inner } def inner = new Inner() } object Child { class Inner extends Parent.Inner { type Self <: Inner } def inner = new Inner() } trait Testable { type Self def test[T <: Self] = {} } object Main { // this works val p: Parent.Inner = Child.inner // this doesn't val h = Parent.inner h.test[Child.Inner] } I get this error: error: type arguments [Child.Inner] do not conform to method test's type parameter bounds [T <: Main.h.Self] h.test[Child.Inner] Why does this error when I my Self type is Parent.Inner and Child.Inner <

Consider the following code class OuterClass{ class InnerClass{ int x; int y; void calculateX(){ x = y+z;//I want to access the y field of the outer class } void printX(){ print(); } } int y; int z; InnerClass instance; OuterClass(int y,int z){ this.y = y; this.z = z; instance = new InnerClass(); instance.y = 10; instance.calculateX(); instance.printX(); } void print(){ System.out.println("X:"+instance.x+"\nY:"+y+"\nZ:"+z+"\n"); } } How to access field of the outer class if there is any overlap in name? I have tried the following: x=super.y; x=OuterClass.y; and received compilation error. Will

I have an inner class (non-static) which is using a reference to an enclosing class in its initialization. Will the inner class keep a reference to the enclosing class now? class Enclosing { class Inner { private final ABC innerField = outerField.computeSomething(); } private final XYZ outerField = something(); } UPDATE I am very much aware that one can reference the outer class with Enclosing.this . But, if the class doesn't use the reference, must the reference be there after compilation? Is it necessary even if the reference is only used in the initialization? Where does it say that an

App runs but the TextView doesn't get update here is the relevant code. activity_picker_dashboard.xml <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent"> <!-- Top header --> <include layout="@layout/layout_header" /> This layout has databinding <!-- DrawerLayout --> <android.support.v4.widget.DrawerLayout android:id="@+id/drawer_layout" android:layout_width="0dp" android:layout_height="0dp" android:background="@color

I'm using Eclipse and I've written a Java application using SWT. When Eclipse compiles my program, it renames my main file into 4 different files like this: MainFile.class MainFile$1.class MainFile$2.class MainFile$3.class When I go to run this program from command line, I get Could not find the main class: MainFile.class. Program will exit. I really don't understand why this is happening. Louis Wasserman The $ classes are for anonymous inner classes and perfectly normal. Could we see the command line you ran? You probably need to write java MainFile instead of java MainFile.class . 来源： https: