添加maven plugin依赖
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-checkstyle-plugin</artifactId>
<version>3.1.2</version>
<configuration>
<configLocation>config/checkstyle.xml</configLocation>
<suppressionsLocation>config/suppressions.xml</suppressionsLocation>
<includeTestSourceDirectory>true</includeTestSourceDirectory>
<encoding>UTF-8</encoding>
<excludes>**/proto/*</excludes>
</configuration>
</plugin>
- configLocation 存放checkstyle的规则配置文件,附录有样例内容
- SuppressionsLocation 存放屏蔽规则配置文件,附录有样例内容
- includeTestSourceDirectory 是否检测测试文件夹,建议配置为true
结束
最后就可以通过mvn checkstyle:check
来检查您的工程啦。如果有违反了checkstyle的地方,命令行会提示出错的地方和违反的规则,如下图所示
附录
规则配置文件举例
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE module PUBLIC
"-//Puppy Crawl//DTD Check Configuration 1.3//EN"
"https://checkstyle.org/dtds/configuration_1_3.dtd">
<!-- This is a checkstyle configuration file. For descriptions of
what the following rules do, please see the checkstyle configuration
page at http://checkstyle.sourceforge.net/config.html -->
<module name="Checker">
<module name="FileTabCharacter">
<!-- Checks that there are no tab characters in the file. -->
</module>
<!-- All Java AST specific tests live under TreeWalker module. -->
<module name="TreeWalker">
<module name="SuppressionCommentFilter">
<property name="offCommentFormat" value="CHECKSTYLE.OFF\: ([\w\|]+)"/>
<property name="onCommentFormat" value="CHECKSTYLE.ON\: ([\w\|]+)"/>
<property name="checkFormat" value="$1"/>
</module>
<module name="SuppressWarningsHolder" />
<!--
IMPORT CHECKS
-->
<module name="RedundantImport">
<!-- Checks for redundant import statements. -->
<property name="severity" value="error"/>
<message key="import.redundancy"
value="Redundant import {0}."/>
</module>
<module name="AvoidStarImport">
<property name="severity" value="error"/>
</module>
<module name="RedundantModifier">
<!-- Checks for redundant modifiers on various symbol definitions.
See: http://checkstyle.sourceforge.net/config_modifier.html#RedundantModifier
-->
<property name="tokens" value="METHOD_DEF, VARIABLE_DEF, ANNOTATION_FIELD_DEF, INTERFACE_DEF, CLASS_DEF, ENUM_DEF"/>
</module>
<!--
IllegalImport cannot blacklist classes, and c.g.api.client.util is used for some shaded
code and some useful code. So we need to fall back to Regexp.
-->
<module name="RegexpSinglelineJava">
<property name="format" value="com\.google\.api\.client\.util\.(ByteStreams|Charsets|Collections2|Joiner|Lists|Maps|Objects|Preconditions|Sets|Strings|Throwables)"/>
</module>
<!--
Require static importing from Preconditions.
-->
<module name="RegexpSinglelineJava">
<property name="format" value="^import com.google.common.base.Preconditions;$"/>
<property name="message" value="Static import functions from Guava Preconditions"/>
</module>
<module name="UnusedImports">
<property name="severity" value="error"/>
<property name="processJavadoc" value="true"/>
<message key="import.unused"
value="Unused import: {0}."/>
</module>
<!--
JAVADOC CHECKS
-->
<!-- Checks for Javadoc comments. -->
<!-- See http://checkstyle.sf.net/config_javadoc.html -->
<module name="JavadocMethod">
<property name="scope" value="protected"/>
<property name="severity" value="error"/>
<property name="allowMissingParamTags" value="true"/>
<property name="allowMissingReturnTag" value="true"/>
</module>
<!-- Check that paragraph tags are used correctly in Javadoc. -->
<!-- <module name="JavadocParagraph"/>-->
<module name="JavadocType">
<property name="scope" value="protected"/>
<property name="severity" value="error"/>
<property name="allowMissingParamTags" value="true"/>
</module>
<module name="JavadocStyle">
<property name="severity" value="error"/>
<property name="checkHtml" value="true"/>
</module>
<!--
NAMING CHECKS
-->
<!-- Item 38 - Adhere to generally accepted naming conventions -->
<module name="PackageName">
<!-- Validates identifiers for package names against the
supplied expression. -->
<!-- Here the default checkstyle rule restricts package name parts to
seven characters, this is not in line with common practice at Google.
-->
<property name="format" value="^[a-z]+(\.[a-z][a-z0-9]{1,})*$"/>
<property name="severity" value="error"/>
</module>
<module name="TypeNameCheck">
<!-- Validates static, final fields against the
expression "^[A-Z][a-zA-Z0-9]*$". -->
<metadata name="altname" value="TypeName"/>
<property name="severity" value="error"/>
</module>
<module name="ConstantNameCheck">
<!-- Validates non-private, static, final fields against the supplied
public/package final fields "^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$". -->
<metadata name="altname" value="ConstantName"/>
<property name="applyToPublic" value="true"/>
<property name="applyToProtected" value="true"/>
<property name="applyToPackage" value="true"/>
<property name="applyToPrivate" value="false"/>
<property name="format" value="^([A-Z][A-Za-z0-9_]*|FLAG_.*)$"/>
<message key="name.invalidPattern"
value="Variable ''{0}'' should be in ALL_CAPS (if it is a constant) or be private (otherwise)."/>
<property name="severity" value="error"/>
</module>
<module name="StaticVariableNameCheck">
<!-- Validates static, non-final fields against the supplied
expression "^[a-z][a-zA-Z0-9]*_?$". -->
<metadata name="altname" value="StaticVariableName"/>
<property name="applyToPublic" value="true"/>
<property name="applyToProtected" value="true"/>
<property name="applyToPackage" value="true"/>
<property name="applyToPrivate" value="true"/>
<property name="format" value="^[a-z][a-zA-Z0-9]*_?$"/>
<property name="severity" value="error"/>
</module>
<module name="MemberNameCheck">
<!-- Validates non-static members against the supplied expression. -->
<metadata name="altname" value="MemberName"/>
<property name="applyToPublic" value="true"/>
<property name="applyToProtected" value="true"/>
<property name="applyToPackage" value="true"/>
<property name="applyToPrivate" value="true"/>
<property name="format" value="^[a-z][a-zA-Z0-9]*$"/>
<property name="severity" value="error"/>
</module>
<module name="MethodNameCheck">
<!-- Validates identifiers for method names. -->
<metadata name="altname" value="MethodName"/>
<property name="format" value="(^[a-z][a-zA-Z0-9]*(_[a-zA-Z0-9]+)*$|Void)"/>
<property name="severity" value="error"/>
</module>
<module name="ParameterName">
<!-- Validates identifiers for method parameters against the
expression "^[a-z][a-zA-Z0-9]*$". -->
<property name="severity" value="error"/>
</module>
<module name="LocalFinalVariableName">
<!-- Validates identifiers for local final variables against the
expression "^[a-z][a-zA-Z0-9]*$". -->
<property name="severity" value="error"/>
</module>
<module name="LocalVariableName">
<!-- Validates identifiers for local variables against the
expression "^[a-z][a-zA-Z0-9]*$". -->
<property name="severity" value="error"/>
</module>
<!-- Type parameters must be either one of the four blessed letters
T, K, V, W, X or else be capital-case terminated with a T,
such as MyGenericParameterT -->
<module name="ClassTypeParameterName">
<property name="format" value="^(((T|K|V|W|X|R)[0-9]*)|([A-Z][a-z][a-zA-Z]*))$"/>
<property name="severity" value="error"/>
</module>
<module name="MethodTypeParameterName">
<property name="format" value="^(((T|K|V|W|X|R)[0-9]*)|([A-Z][a-z][a-zA-Z]*T))$"/>
<property name="severity" value="error"/>
</module>
<module name="InterfaceTypeParameterName">
<property name="format" value="^(((T|K|V|W|X|R)[0-9]*)|([A-Z][a-z][a-zA-Z]*T))$"/>
<property name="severity" value="error"/>
</module>
<module name="LeftCurly">
<!-- Checks for placement of the left curly brace ('{'). -->
<property name="severity" value="error"/>
</module>
<module name="RightCurly">
<!-- Checks right curlies on CATCH, ELSE, and TRY blocks are on
the same line. e.g., the following example is fine:
<pre>
if {
...
} else
</pre>
-->
<!-- This next example is not fine:
<pre>
if {
...
}
else
</pre>
-->
<property name="option" value="same"/>
<property name="severity" value="error"/>
</module>
<!-- Checks for braces around if and else blocks -->
<module name="NeedBraces">
<property name="severity" value="error"/>
<property name="tokens" value="LITERAL_IF, LITERAL_ELSE, LITERAL_FOR, LITERAL_WHILE, LITERAL_DO"/>
</module>
<module name="UpperEll">
<!-- Checks that long constants are defined with an upper ell.-->
<property name="severity" value="error"/>
</module>
<module name="FallThrough">
<!-- Warn about falling through to the next case statement. Similar to
javac -Xlint:fallthrough, but the check is suppressed if a single-line comment
on the last non-blank line preceding the fallen-into case contains 'fall through' (or
some other variants that we don't publicized to promote consistency).
-->
<property name="reliefPattern"
value="fall through|Fall through|fallthru|Fallthru|falls through|Falls through|fallthrough|Fallthrough|No break|NO break|no break|continue on"/>
<property name="severity" value="error"/>
</module>
<!-- Checks for over-complicated boolean expressions. -->
<module name="SimplifyBooleanExpression"/>
<!-- Detects empty statements (standalone ";" semicolon). -->
<module name="EmptyStatement"/>
<!--
WHITESPACE CHECKS
-->
<module name="WhitespaceAround">
<!-- Checks that various tokens are surrounded by whitespace.
This includes most binary operators and keywords followed
by regular or curly braces.
-->
<property name="tokens" value="ASSIGN, BAND, BAND_ASSIGN, BOR,
BOR_ASSIGN, BSR, BSR_ASSIGN, BXOR, BXOR_ASSIGN, COLON, DIV, DIV_ASSIGN,
EQUAL, GE, GT, LAND, LE, LITERAL_CATCH, LITERAL_DO, LITERAL_ELSE,
LITERAL_FINALLY, LITERAL_FOR, LITERAL_IF, LITERAL_RETURN,
LITERAL_SYNCHRONIZED, LITERAL_TRY, LITERAL_WHILE, LOR, LT, MINUS,
MINUS_ASSIGN, MOD, MOD_ASSIGN, NOT_EQUAL, PLUS, PLUS_ASSIGN, QUESTION,
SL, SL_ASSIGN, SR_ASSIGN, STAR, STAR_ASSIGN"/>
<property name="severity" value="error"/>
</module>
<module name="WhitespaceAfter">
<!-- Checks that commas, semicolons and typecasts are followed by
whitespace.
-->
<property name="tokens" value="COMMA, SEMI, TYPECAST"/>
</module>
<module name="NoWhitespaceAfter">
<!-- Checks that there is no whitespace after various unary operators.
Linebreaks are allowed.
-->
<property name="tokens" value="BNOT, DEC, DOT, INC, LNOT, UNARY_MINUS,
UNARY_PLUS"/>
<property name="allowLineBreaks" value="true"/>
<property name="severity" value="error"/>
</module>
<module name="NoWhitespaceBefore">
<!-- Checks that there is no whitespace before various unary operators.
Linebreaks are allowed.
-->
<property name="tokens" value="SEMI, DOT, POST_DEC, POST_INC"/>
<property name="allowLineBreaks" value="true"/>
<property name="severity" value="error"/>
</module>
<module name="OperatorWrap">
<!-- Checks that operators like + and ? appear at newlines rather than
at the end of the previous line.
-->
<property name="option" value="NL"/>
<property name="tokens" value="BAND, BOR, BSR, BXOR, DIV, EQUAL,
GE, GT, LAND, LE, LITERAL_INSTANCEOF, LOR, LT, MINUS, MOD,
NOT_EQUAL, PLUS, QUESTION, SL, SR, STAR "/>
</module>
<module name="OperatorWrap">
<!-- Checks that assignment operators are at the end of the line. -->
<property name="option" value="eol"/>
<property name="tokens" value="ASSIGN"/>
</module>
<module name="ParenPad">
<!-- Checks that there is no whitespace before close parens or after
open parens.
-->
<property name="severity" value="error"/>
</module>
<module name="ModifierOrder"/>
</module>
</module>
屏蔽规则配置文件举例
<?xml version="1.0"?>
<!DOCTYPE suppressions PUBLIC
"-//Puppy Crawl//DTD Suppressions 1.1//EN"
"https://checkstyle.org/dtds/configuration_1_3.dtd">
<suppressions>
<!-- suppress all checks in the generated directories -->
<suppress checks=".*" files=".+[\\/]generated[\\/].+\.java"/>
<suppress checks=".*" files=".+[\\/]generated-sources[\\/].+\.java"/>
<suppress checks=".*" files=".+[\\/]generated-test-sources[\\/].+\.java"/>
</suppressions>