What is the default access specifier in Java

Question

I just started reading a Java book and wondered  which access specifier is the default one  if none is specified

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See here for more details  The default is none of private public protected  but a completely different access specification  It s not widely used  and I prefer to be much more specific in my access definitions

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It depends on what the thing is    Top-level types  that is  classes  enums  interfaces  and annotation types not declared inside another type  are package-private by default   JLS   6 6 1  In classes  all members  that means fields  methods  and nested type declarations  and constructors are package-private by default   JLS   6 6 1    When a class has no explicitly declared constructor  the compiler inserts a default zero-argument constructor which has the same access specifier as the class   JLS   8 8 9  The default constructor is commonly misstated as always being public  but in rare cases that s not equivalent   In enums  constructors are private by default  Indeed  enum contructors must be private  and it is an error to specify them as public or protected  Enum constants are always public  and do not permit any access specifier  Other members of enums are package-private by default   JLS   8 9  In interfaces and annotation types  all members  again  that means fields  methods  and nested type declarations  are public by default  Indeed  members of interfaces and annotation types must be public  and it is an error to specify them as private or protected   JLS   9 3 to 9 5  Local classes are named classes declared inside a method  constructor  or initializer block  They are scoped to the      block in which they are declared and do not permit any access specifier   JLS   14 3  Using reflection  you can instantiate local classes from elsewhere  and they are package-private  although I m not sure if that detail is in the JLS  Anonymous classes are custom classes created with new which specify a class body directly in the expression   JLS   15 9 5  Their syntax does not permit any access specifier  Using reflection  you can instantiate anonymous classes from elsewhere  and both they and their generated constructors are are package-private  although I m not sure if that detail is in the JLS  Instance and static initializer blocks do not have access specifiers at the language level  JLS   8 6  amp  8 7   but static initializer blocks are implemented as a method named  lt clinit gt   JVMS   2 9   so the method must  internally  have some access specifier  I examined classes compiled by javac and by Eclipse s compiler using a hex editor and found that both generate the method as package-private  However  you can t call  lt clinit gt    within the language because the  lt  and  gt  characters are invalid in a method name  and the reflection methods are hardwired to deny its existence  so effectively its access specifier is no access  The method can only be called by the VM  during class initialization  Instance initializer blocks are not compiled as separate methods  their code is copied into each constructor  so they can t be accessed individually  even by reflection

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Update Java 8 usage of default keyword  As many others have noted The default visibility  no keyword      the field will be accessible from inside the same package to which the   class belongs    Not to be confused with the new Java 8 feature  Default Methods  that allows an interface to provide an implementation when its labeled with the default keyword   See  Access modifiers

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The default specifier depends upon context    For classes  and interface declarations  the default is package private  This falls between protected and private  allowing only classes in the same package access   protected is like this  but also allowing access to subclasses outside of the package    class MyClass      package private      int field        package private field     void calc         package private method           For interface members  fields and methods   the default access is public  But note that the interface declaration itself defaults to package private   interface MyInterface     package private      int field1             static final public     void method1           public abstract     If we then have the declaration  public interface MyInterface2 extends MyInterface        Classes using MyInterface2 can then see field1 and method1 from the super interface  because they are public  even though they cannot see the declaration of MyInterface itself

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If no access specifier is given  it s package-level access  there is no explicit specifier for this  for classes and class members  Interface methods are implicitly public

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Here is a quote about package level visibility from an interview with James Gosling  the creator of Java      Bill Venners  Java has four access levels  The default is package  I   have always wondered if making package access default was convenient   because the three keywords that people from C   already knew about   were private  protected  and public  Or if you had some particular   reason that you felt package access should be the default       James Gosling  A package is generally a set of things that are kind of   written together  So generically I could have done one of two things    One was force you always to put in a keyword that gives you the   domain  Or I could have had a default value  And then the question is    what makes a sensible default  And I tend to go for what is the least   dangerous thing       So public would have been a really bad thing to make the default    Private would probably have been a bad thing to make a default  if   only because people actually don t write private methods that often    And same thing with protected  And in looking at a bunch of code that   I had  I decided that the most common thing that was reasonably safe   was in the package  And C   didn t have a keyword for that  because   they didn t have a notion of packages       But I liked it rather than the friends notion  because with friends   you kind of have to enumerate who all of your friends are  and so if   you add a new class to a package  then you generally end up having to   go to all of the classes in that package and update their friends    which I had always found to be a complete pain in the butt       But the friends list itself causes sort of a versioning problem  And   so there was this notion of a friendly class  And the nice thing that   I was making that the default -- I ll solve the problem so what should   the keyword be       For a while there actually was a friendly keyword  But because all the   others start with  P   it was  phriendly  with a  PH   But that was   only in there for maybe a day    http   www artima com intv gosling2P html

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default is a keyword that is used as an access modifier for methods and variables   Using this access modifier will make your class  variable  method or constructor acessible from own class or package  it will be also is set if no access modifier is present     Access Levels     Modifier    Class   Package Subclass  EveryWhere     public        Y        Y       Y         Y     protected     Y        Y       Y         N     default       Y        Y       N         N     private       Y        N       N         N   if you use a default in a interface you will be able to implement a method there like this exemple  public interface Computer           default void Start             throw new UnsupportedOperationException  Error                  However it will only works from the 8 Java version  Official Documentation  Access Modifiers in Java

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There is an access modifier called  default  in JAVA  which allows direct instance creation of that entity only within that package   Here is a useful link   Java Access Modifiers Specifiers

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The default visibility is known as    package-private     though you can t use this explicitly   which means the field will be accessible from inside the same package to which the class belongs   As mdma pointed out  it isn t true for interface members though  for which the default is  public    See Java s Access Specifiers

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First of all let me say one thing  there is no such term as  Access specifier  in java  We should  call everything as  Modifiers    As we know that final  static  synchronised  volatile      are called as modifiers  even Public  private  protected  default  abstract should  also be called as modifiers    Default  is such a modifiers where physical existence is not there but no modifiers  is placed then it should  be treated  as default  modifiers   To justify  this take one example   public class  Simple              public  static  void  main String  args                   System out println  Hello  Java                              Output will be   Hello Java  Now change public to private and see what compiler error you get    It says  Modifier private is not allowed here     What conclusion  is someone can be wrong or some tutorial can be wrong but compiler cannot be wrong  So  we can say there is no term access specifier in java everything  is modifiers

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The default visibility  no keyword  is package which means that it will be available to every class that is located in the same package   Interesting side note is that protected doesn t limit visibility to the subclasses but also to the other classes in the same package

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the default access specifier is package Classes can access the members of other classes in the same package but outside the package it appears as private

[java] What is the default access specifier in Java?

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