add checkstyle.xml, update pom.xml to use maven checkstyle plugin

Author: dota17

checkstyle-suppressions.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0"?>
+
+<!DOCTYPEsuppressions PUBLIC
+ "-//Checkstyle//DTD SuppressionFilter Configuration 1.0//EN"
+ "https://checkstyle.org/dtds/suppressions_1_0.dtd">
+
+<suppressions>
+ <suppresschecks="Javadoc"files="."/>
+ <suppresschecks="MagicNumberCheck"files="."/>
+</suppressions>

pom.xml

@@ -19,6 +19,7 @@
 
 <!-- Maven plugin versions -->
  <bnd.maven.plugin.version>4.3.1</bnd.maven.plugin.version>
+ <maven.checkstyle.plugin.version>3.1.1</maven.checkstyle.plugin.version>
  <maven.compiler.plugin.version>3.7.0</maven.compiler.plugin.version>
  <maven.gpg.plugin.version>1.6</maven.gpg.plugin.version>
  <maven.jar.plugin.version>3.0.2</maven.jar.plugin.version>
@@ -174,6 +175,27 @@
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-compiler-plugin</artifactId>
  </plugin>
+ <plugin>
+ <groupId>org.apache.maven.plugins</groupId>
+ <artifactId>maven-checkstyle-plugin</artifactId>
+ <version>${maven.checkstyle.plugin.version}</version>
+ <configuration>
+ <configLocation>google_checks.xml</configLocation>
+ <suppressionsLocation>checkstyle-suppressions.xml</suppressionsLocation>
+ <suppressionsFileExpression>checkstyle.suppressions.file</suppressionsFileExpression>
+ <consoleOutput>true</consoleOutput>
+ <failsOnError>true</failsOnError>
+ </configuration>
+ <executions>
+ <execution>
+ <id>validate</id>
+ <phase>validate</phase>
+ <goals>
+ <goal>check</goal>
+ </goals>
+ </execution>
+ </executions>
+ </plugin>
  </plugins>
  </build>
  <profiles>