interface - Why are default methods not allowed in annotation types in Java 8? -


Today I saw a glimpse of the wonderful world of annotations, so I applied my code, but I do not want to compile it: / p> 

  public @interface some annotations {say public string 1 (default) "Hello World"; The default public string is called Halo 2 () {Return "Hello World"; }}   
 What do you see in  sayHello1 , how to specify the default logic for annotations. 
 What do I think, so,  is not allowed to say hello 2 , which is available after Java 8.  
 Is providing similar functionality to me, or am I missing something here?  
 By default, java 5 can have access to the default method bodies (albeit very simple ones), while the interface had to wait until Java 8?   
 
 
 this  
  say public string "halo 1" (default) "hello world";   
 The default value of annotation element is providing this, if you have not given it in annotation, then it will be of that value, which will be.  
 
 There can be law announcements in the body of an annotation type,  each of which has defined an element of annotation type.  There is no element other than words defined in an annotation type, it clearly declares the methods.   
 and  
 
 An element of an annotation type can have a default value, which is specified by following the list of element (empty) parameters Is the keyword  default  and a  ElementValue  (§ 9.7.1).   
 then  
  @ SomeNnotation // Say "Hello World" will be public square Foo {} in hello 1   
  @SomeAnnotation (sayHello1 = "Other value") // "Other value" in Halo 1 will be the value of the public category Foo {}   
 Then  
  some annotations n = ...; String value = NISAHL1 ();   
 If you do not value the  default , then you have to provide a price when you make a few comments.  
 This  
  is called the default public string Hello 2 () {Return to "Hello World"; }   
 There is a syntax for a  default  method in a  interface  since java. You can execute anything in this method.  This is not true for an annotation which provides only metadata, not behavior   
 
 Also, why did the annotations have default method bodies (though very simple ones) Java 5, while the interface had to wait up to 8 Java?   
  They did not. The above two things are completely different.

Comments

Post a Comment

Popular posts from this blog

Verilog Error: output or inout port "Q" must be connected to a structural net expression -

I get the error every time, I try to compile. I'm not sure why anyone can help is? I'm new to verilog. Module D_FF (clerk, d, reset_n, q); Input D, Clack, reset_en; Output Q; reg Q; lab4_gdl f1 (.lk (~ clk), d (d), .q.m (qm)); lab4_GDL f2 (.Clk (Clk), D (QM), .Q (Q)); Always start at @ (posedge clk, neggeous reset_n) (Reset_n == 0) Q & lt; = 0; Other questions & lt; = D; Edit End: The problem is what we are asking to do: In this section, you apply the memory / registration circuit on the AlterEdie 2 board. will do. The circuit has the following specifications: The present value of swift SW15-0 on the D2 board should be shown in four hexadecimal four sections of HEX3-0. This part of the circuit will be combination logic. To use an active-less asynchronous reset and KEY1 to use KEY0 as the clock input, you must store SW15-0in in a 16-bit register in the value The register should be enabled to have a 16-bit positive edge, which uses the embedded D flip-flo
Read more

jasper reports - How to center align barcode using jasperreports and barcode4j -

I use iReport 5.5.0 . How to align a barcode component to the center The relevant piece of my jrxml is below & Lt; JR: Code 128 xmlns: JR = "http://jasperreports.sourceforge.net/jasperreports/components" xsi: schemaLocation = "http://jasperreports.sourceforge.net/jasperreports/components http: //jasperreports.sourceforge Purge / xsd / components.xsd "textPosition =" bottom "& gt; & Lt; Jr: codeExpression & gt; & Lt; [CDATA [$ F {number}]] & gt; & Lt; / Jr: codeExpression & gt; & Lt; / Jr: Code 128 & gt; & Lt; / componentElement & gt; "Text" itemprop = "text"> Create a style after this, it is called "barcode", like: & lt; Style name = "barcode" fontName = "Helvetica" fONTSIZE = "10" hAlign = "center" valign = "center" /> and set the property of your barcode element to "barcode".
Read more

c# - ASP.NET MVC - Attaching an entity of type 'MODELNAME' failed because another entity of the same type already has the same primary key value -

In brief, the wrapper module is inserted during posting and the status of an entry is changed to 'modified' . Before changing the state, the state is set to 'separate', but calling attachments () causes the same error to be thrown away. I am using EF 6. Model / wrapper class public class avi model {public A is a {get; Set; } Public listing & lt; B & gt; B {received; Set; } Public cc {receipt; Set; }} Administrator edit public functioning (int? id) {if (id == null) {new HttpStatusCodeResult (HttpStatusCode.BadRequest); } If (! Conveyor Access (id.Value)) new HTTPTitus code result (HTTP status code. Forbidden); Var aViewModel = new AViewModel (); aViewModel.A = db.As.Find (id); If (aViewModel.Receipt == zero) {return HttpNotFound (); } aViewModel.b = db.Bs.Where (x => x.aid == id.Value) .Oolist (); AViewModel.Vendor = db.Cs.Where (x => x.cid == aViewModel.a.cID) .FirstOrDefault (); See Return (aViewModel); } [HTPFost] [Valid AntitiferousTeacon
Read more