Oracle Java Day 2017

Java 9

Latest Java Information Bureau

Compatibility

Underscore-only variables are not supported
The deprecated method may become unusable Reflection relation
Java Plug-in Applet abolished
Windows x86 Client VM is no longer available
Java DB obsolete
Visual VM obsolete
hprof, jhat discontinued

Change directory structure

  jre-9-+-bin
        +-conf
        +-lib

rt.jar, tool.jar, lib / ext obsolete
deprecated CMS

New

Reactive Streams reactive-streams.org
Publisher-Subscriber Model

Flow

Incubator Modules

Non-Final APIs Finalize or Remove in Feature Release HTTP/2 Client

Update

@SafeVarargs

try-with-resources If it is final, you do not have to replace variables in try

    final Reader reader=
    try (reader){

    }catch (Exception e){

    }

Diamond Operator <> Can be used in anonymous classes-> Lambda expressions can be used, so there is not much use
```
    Function<String, String> func = new Function<>(){
        public String apply(String s){}
    }
```
Private Method in Interface

Stream

   ofNullable( t)
   iterate(seed, hasNext, next)
   take/dropWhile
   Collectors.flatMapping
   stream()
   ifPresentOrElse(action, elseAction)
   or(supplier)
   opt=opt1.or(()->opt2);

Collection

   of()

   List<Integer> l = List.of(0,1,2,);
   Map<Integer, String> m = Map.of(0,"a",1,"b");
   Immutable Collection!

String

   char[]->byte[]
   Concatenation
   invokeDynamic

Deprecated