Java Reference
In-Depth Information
Noncompliant Code Example
This noncompliant code example consists of class
Mutable
, which allows the internal ar-
ray object to be modified:
class Mutable {
private int[] array = new int[10];
public int[] getArray() {
return array;
}
public void setArray(int[] i) {
array = i;
}
}
//...
private Mutable mutable = new Mutable();
public Mutable getMutable() {return mutable;}
An untrusted invoker may call the mutator method
setArray(),
and violate the ob-
ject'simmutabilityproperty.Invokingthegettermethod
getArray()
alsoallowsmodific-
ationoftheprivateinternalstateoftheclass.Thisclassalsoviolates
The CERT
®
Oracle
®
Secure Coding Standard for Java
™
[Long 2012], “OBJ05-J. Defensively copy private
mutable class members before returning their references.”
Noncompliant Code Example
This noncompliant code example extends the
Mutable
class with a
MutableProtector
subclass:
class MutableProtector extends Mutable {
@Override
public int[] getArray() {
return super.getArray().clone();
}
}
// ...
private Mutable mutable = new MutableProtector();
