JPCC : Java Glossary

• Accidentally using the same name for a local variable as an instance or static variable. Often when you do this, you really meant to access the instance or static variable.
• Functions with the same name as the class (and thus probably intended as constructors), but that are returning a value.
• Cases (including default) that drop through without break.
• Variable assignments of the form xxx = xxx or this.xxx = xxx, where the assignment may have no effect or may be confusing a local variable with a class / instance variable (i.e., xxx is the same name both sides of the equals).

IDE (Integrated Development Environment) Inspectors now do this checks and the compilers themselves now do many of them.