Since Checkstyle 3.0
if (b == true), b || true, !false,
boolean a = q > 12 ? true : false,
etc.
Rationale: Complex boolean logic makes code hard to understand and maintain.
To configure the check:
<module name="Checker">
<module name="TreeWalker">
<module name="SimplifyBooleanExpression"/>
</module>
</module>
Example:
class Example1 {
void InvalidExample() {
boolean a=true;
boolean b=true;
Object c=null;
Object d=null;
Object e=null;
if (!false) {}; // violation, can be simplified to true
if (a == true) {}; // violation, can be simplified to a
if (a == b) {};
if (a == false) {}; // violation, can be simplified to !a
if (!(a != true)) {}; // violation, can be simplified to a
e = (a || b) ? c : d;
e = (a || false) ? c : d; // violation, can be simplified to a
e = (a && b) ? c : d;
int s = 12;
boolean m = s > 1 ? true : false; // violation, can be simplified to s > 1
boolean f = c == null ? false : c.equals(d);
}
}
All messages can be customized if the default message doesn't suit you. Please see the documentation to learn how to.
com.puppycrawl.tools.checkstyle.checks.coding