The definitions of two constant expressions should be related when, and only when, related exactly when the values they express are also related.
...
Noncompliant Code Example
In this noncompliant code example, OUT_STR_LEN must always be exactly two greater than IN_STR_LEN. These definitions fail to reflect this requirement:
| Code Block | ||
|---|---|---|
| ||
public static final int IN_STR_LEN = 18; public static final int OUT_STR_LEN = 1220; |
...
Compliant Solution
In this compliant solution, the relationship between the two values is represented in the definitions:
| Code Block | ||
|---|---|---|
| ||
public static final int IN_STR_LEN = 18;
public static final int OUT_STR_LEN = IN_STR_LEN + 2;
|
...
Noncompliant Code Example
In this noncompliant code example, there appears to be an underlying relationship between the two constants where none exists.:
| Code Block | ||
|---|---|---|
| ||
public static final int ADULTVOTING_AGE = 18; public static final int ALCOHOL_AGE = ADULTVOTING_AGE + 3; |
A programmer performing routine maintenance may modify the definition for ADULTVOTING_AGE but fail to recognize the resulting change in the definition for ALCOHOL_AGE.
...
Compliant Solution
In this compliant solution, the definitions reflect the independence of the two constants.:
| Code Block | ||
|---|---|---|
| ||
public static final int ADULTVOTING_AGE = 18; public static final int ALCOHOL_AGE = 21; |
4.5 Risk Assessment
Failure to properly encode relationships in constant declarations can lead to unexpected values and can complicate maintenance.
...
...
Severity
...
Likelihood
...
Remediation Cost
...
Priority
...
Level
...
DCL03-J
...
low
...
unlikely
...
high
...
P1
...
L3
4.6 Automated Detection
Automated detection is not currently feasible.
4.7 Related Guidelines
C Secure Coding Standard: DCL08-C. Properly encode relationships in constant definitions
C++ Secure Coding Standard: DCL08-CPP. Properly encode relationships in constant definitions
...
Bibliography
...
...
| [JLS |
...
...
...
...
}} Variables"|http://java.sun.com/docs/books/jls/third_edition/html/typesValues.html#4.12.4]3 DCL02-J. Use meaningful symbolic constants to represent literal values in program logic 01. Declarations and Initialization (DCL) 5 DCL04-J. Do not apply public final to constants whose value might change