Access modifiers in Java

Compared to C + + in public,proctected, private three access control, Java more than the default access control.
Four types of access control permissions in Java are described briefly as four sentences:
1) Private only this class is visible (same as C + +)
2) default to this package visible/in-package access (C + + not)
3) Protected is visible to this package and all subclasses (there is no concept of this package in C + +, more than the default access can be accessed by subclasses under other packages)
4) public visible to all classes (same as C + +)

1) 4) do a simple test with C + +, 2) 3)

3) protected the package is visible to the following tests:

package com.behavior;publicclass Parent {    protectedint3;}

package com.behavior; With parent under the same package, no inheritance relationship  public  class  Children {public  void  action         () {Parent parent = new  parent (); System.    out . Print (PARENT.I); }}

package com.stratege;import com.behavior.Children;publicclass ChildrenTest {        publicstaticvoidmain(String [] args) {            new Children();            children.action();        }}

Authentication: Protected permissions for in-package access

2) default for in-Package access testing
The variable i access permission in parent is modified as follows, children, childrentest unchanged

package com.behavior;publicclass Parent {    int3;}

Validation: Default permissions for in-package access

Access modifiers in Java