参考：

1、https://segmentfault.com/a/1190000008659108

2、https://docs.sonarqube.org/display/DEV/Adding+Coding+Rules

3、https://docs.sonarqube.org/display/DEV/Adding+Coding+Rules+using+Java

4、https://docs.sonarqube.org/display/PLUG/Writing+Custom+Java+Rules+101

有两种方式可以扩展代码规则：但是Java只支持方式1

1、Writing coding rules using Java via a SonarQube plugin

2、Adding XPath rules directly through the SonarQube web interface

Writing coding rules in Java is a six-step process:

• Create a SonarQube plugin.
• Put a dependency on the API of the language plugin for which you are writing coding rules.
• Create as many custom rules as required
• Generate the SonarQube plugin (jar file)
• Place this jar file in the SONARQUBE_HOME/extensions/plugins directory
• Restart SonarQube server

下面详述这个过程：

1、把项目拉到本地

git clone git@github.com:shengulong/sonar-custom-rules-examples.git

2、里面有cobol/java/javascript/php/rpg的自定义规则，我们只关注java的

3、使用intellij idea打开项目java-custom-rules（github上，我已经调试通过）。这是一个maven项目的模板。

4、修改下pom文件:sonar的版本以及对应的java插件版本，这样sonar6.0以上版本都可以用这个插件

 <properties>

         <!--<sonar.version>6.3</sonar.version>-->

         <sonar.version>6.0</sonar.version>

         <!-- this 6.3 is only required to be compliant with SonarLint and it is required

             even if you just want to be compliant with SonarQube 5.6 -->

         <!--<java.plugin.version>4.7.1.9272</java.plugin.version>-->

         <java.plugin.version>4.5.0.8398</java.plugin.version>

         <sslr.version>1.21</sslr.version>

         <gson.version>2.6.2</gson.version>

 </properties>

5、修改下文件，因为最初下载的报编译错误

 @Override

   public void define(Context context) {

     NewRepository repository = context

       .createRepository(REPOSITORY_KEY, "java")

       .setName("MyCompany Custom Repository");

     List<Class> checks = RulesList.getChecks();

     new RulesDefinitionAnnotationLoader().load(repository, Iterables.toArray(checks, Class.class));

     for (Class ruleClass : checks) {

       newRule(ruleClass, repository);

     }

     repository.done();

   }