- Checkstyle provides many checks that you can apply to your - source code. Below is an alphabetical reference, the site - navigation menu provides a reference organized by functionality. -
-| AbbreviationAsWordInName | -The Check validate abbreviations(consecutive capital letters) - length in identifier name, it also allow in enforce camel case naming. | -
| AbstractClassName | -- Ensures that the names of abstract classes conforming to some - regular expression. - | -
| AnnotationLocation | -Check location of annotation on language elements. | -
| AnnotationUseStyle | -This check controls the style with the usage of annotations. | -
| AnonInnerLength | -Checks for long anonymous inner classes. | -
| ArrayTrailingComma | -Checks if array initialization contains optional trailing comma. | -
| ArrayTypeStyle | -Checks the style of array type definitions. | -
| AtclauseOrder | -Checks the order of at-clauses. | -
| AvoidEscapedUnicodeCharacters | -Restrict using Unicode escapes. | -
| AvoidInlineConditionals | -Detects inline conditionals. | -
| AvoidNestedBlocks | -Finds nested blocks. | -
| AvoidStarImport | -Check that finds import statements that use the * notation. | -
| AvoidStaticImport | -Check that finds static imports. | -
| BooleanExpressionComplexity | -- Restricts nested boolean operators (&&, ||, &, | - and ^) to a specified depth (default = 3). - | -
| ClassDataAbstractionCoupling | -This metric measures the number of instantiations of other classes within the given class. | -
| ClassFanOutComplexity | -The number of other classes a given class relies on. | -
| ClassTypeParameterName | -- Checks that class type parameter names conform to a format - specified by the format property. - | -
| ConstantName | -Checks that constant names conform to a format specified by the format property. | -
| CovariantEquals | -- Checks that if a class defines a covariant method equals, then - it defines method equals(java.lang.Object). - | -
| CustomImportOrder | -- Checks that the groups of import declarations appear in the order specified - by the user. - | -
| CyclomaticComplexity | -Checks cyclomatic complexity against a specified limit. | -
| DeclarationOrder | -- Checks that the parts of a class or interface declaration - appear in the order suggested by the Code Conventions for the Java Programming Language. - | -
| DefaultComesLast | -
- Check that the default is after all the
- cases in a switch statement.
- |
-
| DescendantToken | -Checks for restricted tokens beneath other tokens. | -
| DesignForExtension | -Checks that classes are designed for inheritance. | -
| EmptyBlock | -Checks for empty blocks. | -
| EmptyCatchBlock | -Checks for empty catch blocks with few options to skip violation. | -
| EmptyForInitializerPad | -Checks the padding of an empty for initializer; that is whether a - space is required at an empty for initializer, or such spaces are - forbidden. | -
| EmptyForIteratorPad | -Checks the padding of an empty for iterator; that is whether a - space is required at an empty for iterator, or such spaces are - forbidden. | -
| EmptyLineSeparator | -Checks for blank line separators. | -
| EmptyStatement | -- Detects empty statements (standalone ';'). | -
| EqualsAvoidNull | -- Checks that any combination of String literals with optional - assignment is on the left side of an equals() comparison. | -
| EqualsHashCode | -- Checks that classes that override equals() also override hashCode(). | -
| ExecutableStatementCount | -- Restricts the number of executable statements to a specified - limit (default = 30). - | -
| ExplicitInitialization | -
- Checks if any class or object member explicitly initialized
- to default for its type value (null for object
- references, zero for numeric types and char
- and false for boolean.
- |
-
| FallThrough | -Checks for fall through in switch statements - Finds locations where a case contains Java code - - but lacks a break, return, throw or continue statement. | -
| FileLength | -- Checks for long source files. | -
| FileTabCharacter | -Checks to see if a file contains a tab character. | -
| FinalClass | -- Checks that class which has only private ctors - is declared as final. | -
| FinalLocalVariable | -- Ensures that local variables that never get their values changed, - must be declared final. | -
| FinalParameters | -Check that method/constructor/catch/foreach parameters are final. | -
| GenericWhitespace | -Checks that the whitespace around the Generic tokens < and > are - correct to the typical convention. | -
| Header | -Checks the header of the source against a fixed header file. | -
| HiddenField | -Checks that a local variable or a parameter does not shadow - a field that is defined in the same class. | -
| HideUtilityClassConstructor | -Make sure that utility classes (classes that contain only static methods) - do not have a public constructor. | -
| IllegalCatch | -Catching java.lang.Exception, java.lang.Error or java.lang.RuntimeException - is almost never acceptable. | -
| IllegalImport | -- Checks for imports from a set of illegal packages. | -
| IllegalInstantiation | -- Checks for illegal instantiations where a factory method is preferred. | -
| IllegalThrows | -Throwing java.lang.Error or java.lang.RuntimeException - is almost never acceptable. | -
| IllegalToken | -- Checks for illegal tokens. | -
| IllegalTokenText | -- Checks for illegal token text. | -
| IllegalType | -- Checks that particular class are never used as types in variable - declarations, return values or parameters. | -
| ImportControl | -Check that controls what packages can be imported in each package. | -
| ImportOrder | -Ensures that groups of imports come in a specific order. | -
| Indentation | -Checks correct indentation of Java Code. | -
| InnerAssignment | -
- Checks for assignments in subexpressions, such as in
- String s = Integer.toString(i = 2);. |
-
| InnerTypeLast | -- Check nested (internal) classes/interfaces are declared at the bottom of the - class after all method and field declarations. | -
| InterfaceIsType | -Implements Bloch, Effective Java, Item 17 - - Use Interfaces only to define types. | -
| InterfaceTypeParameterName | -- Checks that interface type parameter names conform to a format specified - by the format property. | -
| JavaNCSS | -This check calculates the Non Commenting Source Statements (NCSS) metric for - Java source files and methods. | -
| JavadocMethod | -Checks the Javadoc of a method or constructor. | -
| JavadocPackage | -Checks that all packages have a package documentation. | -
| JavadocTagContinuationIndentation | -Checks the indentation of the continuation lines in at-clauses. | -
| JavadocParagraph | -Checks Javadoc paragraphs. | -
| JavadocStyle | -Custom Checkstyle Check to validate Javadoc. | -
| JavadocType | -Checks the Javadoc of a type. | -
| JavadocVariable | -Checks that a variable has Javadoc comment. | -
| LeftCurly | -- Checks the placement of left curly braces on types, methods and - other blocks: - | -
| LineLength | -Checks for long lines. | -
| LocalFinalVariableName | -- Checks that local final variable names conform to a format specified - by the format property. | -
| LocalVariableName | -- Checks that local, non-final variable names conform to a format specified - by the format property. | -
| MagicNumber | -- Checks for magic numbers. | -
| MemberName | -- Checks that instance variable names conform to a format specified - by the format property. | -
| MethodCount | -Checks the number of methods declared in each type. | -
| MethodLength | -- Checks for long methods. | -
| MethodName | -- Checks that method names conform to a format specified - by the format property. | -
| MethodParamPad | -- Checks the padding between the identifier of a method definition, - constructor definition, method call, or constructor invocation; - and the left parenthesis of the parameter list. | -
| MethodTypeParameterName | -- Checks that class type parameter names conform to a format specified - by the format property. | -
| MissingCtor | -- Checks that classes (except abstract one) define a ctor and don't rely - on the default one. | -
| MissingDeprecated | -- This class is used to verify that both the - | -
| MissingOverride | -- This class is used to verify that the | -
| MissingSwitchDefault | -- Checks that switch statement has "default" clause. | -
| ModifiedControlVariable | -Check for ensuring that for loop control variables are not modified - inside the for block. | -
| ModifierOrder | -- Checks that the order of modifiers conforms to the suggestions in the - - Java Language specification, sections 8.1.1, 8.3.1 and 8.4.3. | -
| MultipleStringLiterals | -Checks for multiple occurrences of the same string literal within a - single file. | -
| MultipleVariableDeclarations | -- Checks that each variable declaration is in its own statement - and on its own line. | -
| MutableException | -Ensures that exceptions (defined as any class name conforming - to some regular expression) are immutable. | -
| NPathComplexity | -Checks the npath complexity against a specified limit (default = 200). | -
| NeedBraces | -- Checks for braces around code blocks. | -
| NestedForDepth | -Restricts nested for blocks to a specified depth (default = 1). |
-
| NestedIfDepth | -Restricts nested if-else blocks to a specified depth (default = 1). | -
| NestedTryDepth | -Restricts nested try-catch-finally blocks to a specified depth (default = 1). | -
| NewlineAtEndOfFile | -- Checks that there is a newline at the end of each file. | -
| NoClone | -- Checks that the clone method is not overridden from the - Object class. | -
| NoFinalizer | -Checks that no method having zero parameters is defined - using the name finalize. | -
| NonEmptyAtclauseDescription | -- Checks that the at-clause tag is followed by description . | -
| NoLineWrap | -- Checks that chosen statements are not line-wrapped. | -
| NoWhitespaceAfter | -- Checks that there is no whitespace after a token. | -
| NoWhitespaceBefore | -- Checks that there is no whitespace before a token. | -
| OneStatementPerLine | -Checks there is only one statement per line. | -
| OneTopLevelClass | -Checks that each top-level class, interfaces or enum resides in a source file of its own. | -
| OperatorWrap | -- Checks line wrapping for operators. | -
| OuterTypeFilename | -Checks that the outer type name and the file name match. | -
| OuterTypeNumber | -Checks for the number of defined types at the "outer" level. | -
| OverloadMethodsDeclarationOrder | -Checks that overload methods are grouped together. | -
| PackageAnnotation | -This check makes sure that all package annotations are in the - package-info.java file. | -
| PackageDeclaration | -Ensures there is a package declaration and (optionally) in the correct directory. | -
| PackageName | -- Checks that package names conform to a format specified - by the format property. | -
| ParameterAssignment | -- Disallow assignment of parameters. | -
| ParameterName | -- Checks that parameter names conform to a format specified - by the format property. | -
| ParameterNumber | -- Checks the number of parameters that a method or constructor has. | -
| ParenPad | -Checks the padding of parentheses; that is whether a space is required - after a left parenthesis and before a right parenthesis, or such spaces are - forbidden, with the exception that it does - not check for padding of the right parenthesis at an empty for iterator. | -
| RedundantImport | -- Checks for imports that are redundant. | -
| RedundantModifier | -Checks for redundant modifiers in interface and annotation definitions. | -
| Regexp | -- A check that makes sure that a specified pattern exists (or not) in the file. | -
| RegexpHeader | -Checks the header of the source against a header file that contains a - | -
| RegexpMultiline | -Implementation of a check that looks that matches across multiple lines in - any file type. | -
| RegexpSingleline | -Implementation of a check that looks for a single line in any file type. | -
| RegexpSinglelineJava | -Implementation of a check that looks for a single line in Java files. | -
| RequireThis | -Checks that code doesn't rely on the "this" default. | -
| ReturnCount | -- Restricts return statements to a specified count (default = 2). | -
| RightCurly | -- Checks the placement of right curly braces. | -
| SeparatorWrap | -- Checks line wrapping with separators. | -
| SingleLineJavadoc | -- Checks that a JavaDoc block which can fit on a single line and doesn't contain at-clauses | -
| SimplifyBooleanExpression | -- Checks for overly complicated boolean expressions. | -
| SimplifyBooleanReturn | -- Checks for overly complicated boolean return statements. | -
| StaticVariableName | -- Checks that static, non-final variable names conform to a format specified - by the format property. | -
| StringLiteralEquality | -Checks that string literals are not used with
- == or !=. |
-
| SummaryJavadoc | -- Checks that Javadoc summary sentence does not contain phrases that are not recommended to use. | -
| SuperClone | -- Checks that an overriding clone() method invokes super.clone(). | -
| SuperFinalize | -- Checks that an overriding finalize() method invokes super.finalize(). | -
| SuppressWarnings | -- This check allows you to specify what warnings that - | -
| SuppressWarningsHolder | -- This check allows for finding code that should not be reported by Checkstyle - | -
| ThrowsCount | -- Restricts throws statements to a specified count (default = 1). | -
| TodoComment | -- A check for TODO comments. | -
| TrailingComment | -- The check to ensure that requires that comments be the only thing on a line. | -
| Translation | -- The TranslationCheck class helps to ensure the correct translation of code by - checking property files for consistency regarding their keys. | -
| TypeName | -- Checks that type names conform to a format specified - by the format property. | -
| TypecastParenPad | -Checks the padding of parentheses for typecasts. | -
| UncommentedMain | -Detects uncommented main methods. | -
| UniqueProperties | -Detects duplicated keys in properties files. | -
| UnnecessaryParentheses | -- Checks if unnecessary parentheses are used in a statement or expression. | -
| UnusedImports | -- Checks for unused import statements. | -
| UpperEll | -Checks that long constants are defined with an upper ell. | -
| VariableDeclarationUsageDistance | -Checks the distance between declaration of variable and its first usage. | -
| VisibilityModifier | -Checks visibility of class members. | -
| WhitespaceAfter | -- Checks that a token is followed by whitespace, with the exception that it - does not check for whitespace after the semicolon of an empty for iterator. | -
| WhitespaceAround | -- Checks that a token is surrounded by whitespace. | -
| WriteTag | -- Outputs a JavaDoc tag as information. | -