IDEA使用CheckStyle代码规范

IDEA使用CheckStyle代码规范说明

前言：

CheckStyle是SourceForge下的一个项目，提供了一个帮助JAVA开发人员遵守某些编码规范的工具。它能够自动化代码规范检查过程，从而使得开发人员从这项重要，但是枯燥的任务中解脱出来。

CheckStyle检验的主要内容

·Javadoc注释

·命名约定

·标题

·Import语句

·体积大小

·空白

·修饰符

·块

·代码问题

·类设计

·混合检查（包括一些有用的比如非必须的System.out和printstackTrace）

从上面可以看出，CheckStyle提供了大部分功能都是对于代码规范的检查，而没有提供像PMD和Jalopy那么多的增强代码质量和修改代码的功能。但是，对于团队开发，尤其是强调代码规范的公司来说，它的功能已经足够强大。

第一步 下载CheckStyle-IDEA插件

点击Browse repositories–>再搜索CheckStyle–>找到CheckStyle-IDEA–>再点击Install–>自动安装完成后重启
第二步 导入规则文件

找到Other Settings –>点击Checkstyle–>再点击Configuration File的加号

先填写规则描述名–>然后点击Browse导入规则文件–>点击Next–再点击Finish

（或者是自带的谷歌和sun的规范）

第三步 使用

点击状态栏上的CheckStyle按钮，点击（红叉按钮下）旁边的Check project 或者check Module按钮，检查工程的不规则编码和习惯

双击不规范列表的一条数据，直接进入界面修改不规范代码

如果需要界面不报异常红，勾选Treat Checkstyle errors as warnings，最后重启工程或AS

备注一：

Check.xml

代码示例

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.2//EN" "http://www.puppycrawl.com/dtds/configuration_1_2.dtd"><!-- sumavision代码格式检查 --><module name="Checker">​    ​	<property name="charset" value="UTF-8" />​	<property name="severity" value="warning" />​	<module name="TreeWalker">​			<!-- Checks for imports -->​			<!-- 必须导入类的完整路径，即不能使用*导入所需的类 -->​			<module name="AvoidStarImport" />​		<!-- 检查是否从非法的包中导入了类 illegalPkgs: 定义非法的包名称 -->​		<module name="IllegalImport" /> <!-- defaults to sun.* packages -->​		<!-- 检查是否导入了不必显示导入的类 -->​		<module name="RedundantImport" />​		<!-- 检查是否导入的包没有使用 -->​		<module name="UnusedImports" />​		<!-- Checks for Naming Conventions. 命名规范 -->​		<!-- local, final variables, including catch parameters -->​		<module name="LocalFinalVariableName" />​		<!-- local, non-final variables, including catch parameters -->​		<module name="LocalVariableName" />​		<!-- static, non-final fields -->​		<module name="StaticVariableName">​			<property name="format" value="(^[A-Za-z0-9_]{0,32}$)" />​		</module>​		<!-- packages -->​		<module name="PackageName">​			<property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$" />​		</module>​		<!-- classes and interfaces -->​		<module name="TypeName">​			<property name="format" value="(^[A-Z][a-zA-Z0-9]{0,31}$)" />​		</module>​		<!-- methods -->​		<module name="MethodName">​			<property name="format" value="(^[a-z][a-zA-Z0-9]{0,38}$)" />​		</module>​		<!-- non-static fields -->​		<!-- 对应的接口已定 参数先不做修改​		<module name="MemberName">​			<property name="format" value="(^[a-z][a-z0-9][a-zA-Z0-9]{0,30}$)" />​		</module> -->​        <module name="MemberName">​            <property name="format" value="(^[a-z][a-zA-Z0-9]{0,31}$)" />​        </module>​		<!-- parameters -->​		<module name="ParameterName">​			<property name="format" value="(^[a-z][a-zA-Z0-9_]{0,31}$)" />​		</module>​		<!-- constants (static, final fields) -->​		<module name="ConstantName">​			<property name="format" value="(^[A-Z0-9_]{0,38}$)" />​		</module>​		<!--option: 定义左大括号'{'显示位置，eol在同一行显示，nl在下一行显示 maxLineLength: 大括号'{'所在行行最多容纳的字符数​           tokens: 该属性适用的类型，例：CLASS_DEF,INTERFACE_DEF,METHOD_DEF,CTOR_DEF -->​		<module name="LeftCurly">​			<property name="option" value="eol" />​		</module>​		<!-- Checks the placement of right curly braces ('}') for else, try, and​           catch tokens. The policy to verify is specified using property option. option:​           右大括号是否单独一行显示 tokens: 定义检查的类型-->​		<module name="RightCurly">​			<property name="option" value="alone" />​			<property name="tokens" value="LITERAL_IF, LITERAL_FOR, LITERAL_WHILE, LITERAL_FINALLY"/>​	  	<!--	<property name="tokens" value="LITERAL_ELSE,LITERAL_IF, LITERAL_FOR, LITERAL_WHILE, LITERAL_FINALLY"/> -->​		</module>​		<!-- NeedBraces 检查是否应该使用括号的地方没有加括号 tokens: 定义检查的类型 -->​		<module name="NeedBraces" />​		<!-- 代码缩进 -->​		<module name="Indentation" >​			<property name="arrayInitIndent" value="4"/>​		</module>​		<!-- 每一行只能定义一个变量 -->​		<module name="MultipleVariableDeclarations" />​		<!-- Checks the style of array type definitions. Some like Java-style:​           public static void main(String[] args) and some like C-style: public static​           void main(String args[]) 检查再定义数组时，采用java风格还是c风格，例如：int[] num是java风格，int num[]是c风格。默认是java风格 -->​		<module name="ArrayTypeStyle" />​		<!-- Checks that switch statement has "default" clause. 检查switch语句是否有‘default’从句​           Rationale: It's usually a good idea to introduce a default case in every​           switch statement. Even if the developer is sure that all currently possible​           cases are covered, this should be expressed in the default branch, e.g. by​           using an assertion. This way the code is protected aginst later changes,​           e.g. introduction of new types in an enumeration type. -->​		<module name="MissingSwitchDefault" />​		<!--检查switch中case后是否加入了跳出语句，例如：return、break、throw、continue -->​		<module name="FallThrough" />​		<!--检查default是否在语句的最后 -->​		<module name="DefaultComesLast">​			<property name="severity" value="warning"/>​		</module>​		<!-- ModifierOrder 检查修饰符的顺序，默认是 public,protected,private,abstract,static,final,transient,volatile,synchronized,native -->​		<module name="ModifierOrder" />​		<!-- 每行字符数为150 -->​		<module name="LineLength">​			<property name="max" value="150" />​		</module>​		<!-- 不允许使用魔法数​		<module name="MagicNumber" />-->​		<!-- 禁用Finalizers -->​		<module name="NoFinalizer" />​		<!-- 每行一条语句 -->​		<module name="OneStatementPerLine" />​		<!-- 检查是否跨越分支 在有跨越分支的case分支代码中添加“fallthru”、“fall through”、“fallthrough”、​        “falls through”、“fallsthrough”等注释（区分大小写）时，便可抑制警告。-->​		<module name="FallThrough" />​		<!-- 检查所有的重载放在一起 -->​		<module name="OverloadMethodsDeclarationOrder"/>​		<!-- 检查是否有多余的修饰符，例如：接口中的方法不必使用public、abstract修饰 -->​		<module name="RedundantModifier" />​		<!-- 检查方法的javadoc的注释 scope: 可以检查的方法的范围，例如：public只能检查public修饰的方法，private可以检查所有的方法​           allowMissingParamTags: 是否忽略对参数注释的检查 allowMissingThrowsTags: 是否忽略对throws注释的检查​           allowMissingReturnTag: 是否忽略对return注释的检查 -->​		<module name="JavadocMethod">​			<property name="scope" value="private" />​			<property name="allowMissingParamTags" value="true" />​			<property name="allowMissingThrowsTags" value="true" />​			<property name="allowMissingReturnTag" value="true" />​			<property name="tokens" value="METHOD_DEF" />​			<property name="allowUndeclaredRTE" value="true" />​			<property name="allowThrowsTagsForSubclasses" value="true" />​			<!-- 允许get set 方法没有注释 -->​			<property name="allowMissingPropertyJavadoc" value="true" />​		</module>​		<!-- 检查在重写了equals方法后是否重写了hashCode方法 -->​		<module name="EqualsHashCode" />​		<!-- Checks for overly complicated boolean expressions. Currently finds​           code like if (b == true), b || true, !false, etc. 检查boolean值是否冗余的地方 Rationale:​           Complex boolean logic makes code hard to understand and maintain. -->​		<module name="SimplifyBooleanExpression" />​		<!-- Checks for overly complicated boolean return statements. For example​           the following code 检查是否存在过度复杂的boolean返回值 if (valid()) return false; else​           return true; could be written as return !valid(); The Idea for this Check​           has been shamelessly stolen from the equivalent PMD rule. -->​		<module name="SimplifyBooleanReturn" />​		<!-- Checks that a class which has only private constructors is declared​           as final.只有私有构造器的类必须声明为final -->​		<module name="FinalClass" />​		<!-- Make sure that utility classes (classes that contain only static methods​           or fields in their API) do not have a public constructor. 确保Utils类（只提供static方法和属性的类）没有public构造器。​           Rationale: Instantiating utility classes does not make sense. Hence the constructors​           should either be private or (if you want to allow subclassing) protected.​           A common mistake is forgetting to hide the default constructor. If you make​           the constructor protected you may want to consider the following constructor​           implementation technique to disallow instantiating subclasses: public class​           StringUtils // not final to allow subclassing { protected StringUtils() {​           throw new UnsupportedOperationException(); // prevents calls from subclass​           } public static int count(char c, String s) { // ... } } -->​		<module name="HideUtilityClassConstructor" />​		<!-- Checks visibility of class members. Only static final members may​           be public; other class members must be private unless property protectedAllowed​           or packageAllowed is set. 检查class成员属性可见性。只有static final 修饰的成员是可以public的。其他的成员属性必需是private的，除非属性protectedAllowed或者packageAllowed设置了true.​           Public members are not flagged if the name matches the public member regular​           expression (contains "^serialVersionUID$" by default). Note: Checkstyle 2​           used to include "^f[A-Z][a-zA-Z0-9]*$" in the default pattern to allow CMP​           for EJB 1.1 with the default settings. With EJB 2.0 it is not longer necessary​           to have public access for persistent fields, hence the default has been changed.​           Rationale: Enforce encapsulation. 强制封装 -->​		<module name="VisibilityModifier" />​		<!-- Checks that long constants are defined with an upper ell. That is​           ' L' and not 'l'. This is in accordance to the Java Language Specification,​           Section 3.10.1. 检查是否在long类型是否定义了大写的L.字母小写l和数字1（一）很相似。 looks a lot like 1. -->​		<module name="UpperEll" />​		<!-- Checks the number of parameters of a method or constructor. max default 7个. -->​		<module name="ParameterNumber" >​            <property name="max" value="8"/>​    </module>​		<!-- Checks for long methods and constructors. max default 150行. max=300 设置长度300 -->​		<module name="MethodLength">​			<property name="max" value="300" />​		</module>​		<!--- 字符串比较必须使用 equals() -->​		<module name="StringLiteralEquality">​		</module>​		<!-- if-else嵌套语句个数 最多4层 -->​		<module name="NestedIfDepth">​			<property name="max" value="4" />​		</module>​		<!-- try-catch 嵌套语句个数 最多2层 -->​		<module name="NestedTryDepth">​			<property name="max" value="2" />​		</module>​		<!-- 返回个数​		<module name="ReturnCount">​			<property name="max" value="10" />​			<property name="format" value="^$" />​		</module>-->​		​    </module></module>

备注二

下载相关文件 https://github.com/checkstyle/checkstyle/releases/

xml https://checkstyle.sourceforge.io/

备注三

在源代码中可以使用快捷键将代码依照Google Java Style Guide进行格式化:

Ctrl + Alt + L 格式化代码

Ctrl + Alt + I 自动缩进

Ctrl + Alt + O 整理import