| Wiki Markup |
|---|
Immutability helps to supporting security reasoning. It is safe to share immutable objects, without risk that the recipient can modify something that we are relying upon \[[Mettler 2010B|AA. Bibliography#Mettler 2010B]\]. |
| Wiki Markup |
|---|
Programmers could incorrectly expect that declaring a field or variable {{final}} makes the referenced object immutable. Declaring variables that have a primitive type to be {{final}} does prevent changes to their values after initialization (unless the unsupported {{sun.misc.Unsafe}} class is used). However, when the variable has a reference type, the presence of a {{final}} clause in the declaration only makes _the reference itself_ immutable. The {{final}} clause has no effect on the referenced object. Consequently, the fields of the referenced object can be mutable. For example, according to the _Java Language Specification_ \[[JLS 2005|AA. Bibliography#JLS 05]\], [§4.12.4|http://java.sun.com/docs/books/jls/third_edition/html/typesValues.html#4.12.4], "{{final}} Variables," |
...
| Wiki Markup |
|---|
\[[Bloch 2008|AA. Bibliography#Bloch 08]\] Item 13: Minimize the accessibility of classes and members
\[[Core Java 2004|AA. Bibliography#Core Java 04]\] Chapter 6
\[[JLS 2005|AA. Bibliography#JLS 05]\] [§4.12.4 "final Variables"|http://java.sun.com/docs/books/jls/third_edition/html/typesValues.html#4.12.4] and [§6.6 "Access Control"|http://java.sun.com/docs/books/jls/third_edition/html/names.html#6.6]
\[[Mettler 2010B|AA. Bibliography#Mettler 2010B]\] |
...
OBJ01-J. Declare data members as private and provide accessible wrapper methods 04. Object Orientation (OBJ) OBJ03-J. Sensitive classes must not let themselves be copied