Java Code Quality Checklist and Eclipse Formatting Tips

After cleaning up an existing Java project, the author compiled a list of recurring code‑quality issues identified by tools like CheckStyle, FindBugs, and PMD, and shares them to help peers improve maintainability.

Eclipse shortcuts: Use Ctrl+Shift+F to format source code and Ctrl+Shift+O to organize imports; you can also enable automatic formatting and import management on save via Window → Preferences → Java → Editor → Save Actions .

Avoid multiple return statements: Ensure each method has a single exit point; multiple return statements are discouraged.

Simplify if‑else logic: Consolidate simple conditional checks into a single utility method that returns a value based on the condition.

Do not create new Boolean, Integer, or String instances: Prefer factory methods such as Boolean.valueOf(true) over new Boolean(true) to improve performance.

Always use braces around block statements: Enclose the bodies of if , for , while , etc., in braces to avoid ambiguity and potential bugs.

Declare method parameters as final when possible: This triggers compile‑time warnings on accidental modifications and can lead to bytecode optimizations.

Name public static final fields in uppercase: Use uppercase naming for constants to distinguish them from regular variables.

Combine multiple if statements into one when appropriate: Reduce redundant checks by merging conditions.

Always add a default clause to switch statements: Guarantees handling of unexpected values.

Avoid repeated string literals: Define a constant for a string that is used in multiple places.

These guidelines, originally sourced from the “java一日一条” series, aim to help developers write cleaner, more efficient Java code.