diff --git a/checkstyle.xml b/checkstyle.xml
new file mode 100644
index 000000000..e79788f46
--- /dev/null
+++ b/checkstyle.xml
@@ -0,0 +1,202 @@
+<?xml version="1.0"?>
+<!DOCTYPE module PUBLIC
+        "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
+        "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">
+
+<!--
+
+    Source = https://github.com/checkstyle/checkstyle/tree/master/src/main/resources
+
+    Checkstyle configurartion that checks the Google coding conventions from:
+    
+    -  Google Java Style
+       https://google-styleguide.googlecode.com/svn-history/r130/trunk/javaguide.html
+       
+    Checkstyle is very configurable. Be sure to read the documentation at
+    http://checkstyle.sf.net (or in your downloaded distribution).
+
+    Most Checks are configurable, be sure to consult the documentation.
+
+    To completely disable a check, just comment it out or delete it from the file.
+
+    Authors: Max Vetrenko, Ruslan Diachenko, Roman Ivanov.
+    
+ -->
+
+<module name = "Checker">
+    <property name="charset" value="UTF-8"/>
+
+    <property name="severity" value="warning"/>
+
+    <!-- Checks for whitespace                               -->
+    <!-- See http://checkstyle.sf.net/config_whitespace.html -->
+    <module name="FileTabCharacter">
+        <property name="eachLine" value="true"/>
+    </module>
+
+    <module name="TreeWalker">
+        <module name="OuterTypeFilename"/>
+        <module name="IllegalTokenText">
+            <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL"/>
+            <property name="format" value="\\u00(08|09|0(a|A)|0(c|C)|0(d|D)|22|27|5(C|c))|\\(0(10|11|12|14|15|42|47)|134)"/>
+            <property name="message" value="Avoid using corresponding octal or Unicode escape."/>
+        </module>
+        <module name="AvoidEscapedUnicodeCharacters">
+            <property name="allowEscapesForControlCharacters" value="true"/>
+            <property name="allowByTailComment" value="true"/>
+            <property name="allowNonPrintableEscapes" value="true"/>
+        </module>
+        <module name="LineLength">
+            <property name="max" value="100"/>
+            <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
+        </module>
+        <module name="AvoidStarImport"/>
+        <module name="OneTopLevelClass"/>
+        <module name="NoLineWrap"/>
+        <module name="EmptyBlock">
+            <property name="option" value="TEXT"/>
+            <property name="tokens" value="LITERAL_TRY, LITERAL_CATCH, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_SWITCH"/>
+        </module>
+        <module name="NeedBraces"/>
+        <module name="LeftCurly">
+            <property name="maxLineLength" value="100"/>
+        </module>
+        <module name="RightCurly"/>
+        <module name="RightCurly">
+            <property name="option" value="alone"/>
+            <property name="tokens" value="CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_FOR, LITERAL_WHILE, LITERAL_DO, STATIC_INIT, INSTANCE_INIT"/>
+        </module>
+        <module name="WhitespaceAround">
+            <property name="allowEmptyConstructors" value="true"/>
+            <property name="allowEmptyMethods" value="true"/>
+            <property name="allowEmptyTypes" value="true"/>
+            <property name="allowEmptyLoops" value="true"/>
+            <message key="ws.notFollowed"
+                     value="WhitespaceAround: ''{0}'' is not followed by whitespace."/>
+            <message key="ws.notPreceded"
+                     value="WhitespaceAround: ''{0}'' is not preceded with whitespace."/>
+        </module>
+        <module name="OneStatementPerLine"/>
+        <module name="MultipleVariableDeclarations"/>
+        <module name="ArrayTypeStyle"/>
+        <module name="MissingSwitchDefault"/>
+        <module name="FallThrough"/>
+        <module name="UpperEll"/>
+        <module name="ModifierOrder"/>
+        <module name="EmptyLineSeparator">
+            <property name="allowNoEmptyLineBetweenFields" value="true"/>
+        </module>
+        <module name="SeparatorWrap">
+            <property name="tokens" value="DOT"/>
+            <property name="option" value="nl"/>
+        </module>
+        <module name="SeparatorWrap">
+            <property name="tokens" value="COMMA"/>
+            <property name="option" value="EOL"/>
+        </module>
+        <module name="PackageName">
+            <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
+            <message key="name.invalidPattern"
+                     value="Package name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="TypeName">
+            <message key="name.invalidPattern"
+                     value="Type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="MemberName">
+            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9]*$"/>
+            <message key="name.invalidPattern"
+                     value="Member name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="ParameterName">
+            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9]*$"/>
+            <message key="name.invalidPattern"
+                     value="Parameter name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="LocalVariableName">
+            <property name="tokens" value="VARIABLE_DEF"/>
+            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9]*$"/>
+            <property name="allowOneCharVarInForLoop" value="true"/>
+            <message key="name.invalidPattern"
+                     value="Local variable name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="ClassTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+                     value="Class type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="MethodTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+                     value="Method type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="NoFinalizer"/>
+        <module name="GenericWhitespace">
+            <message key="ws.followed"
+                     value="GenericWhitespace ''{0}'' is followed by whitespace."/>
+            <message key="ws.preceded"
+                     value="GenericWhitespace ''{0}'' is preceded with whitespace."/>
+            <message key="ws.illegalFollow"
+                     value="GenericWhitespace ''{0}'' should followed by whitespace."/>
+            <message key="ws.notPreceded"
+                     value="GenericWhitespace ''{0}'' is not preceded with whitespace."/>
+        </module>
+        <module name="Indentation">
+            <property name="basicOffset" value="2"/>
+            <property name="braceAdjustment" value="0"/>
+            <property name="caseIndent" value="2"/>
+            <property name="throwsIndent" value="4"/>
+            <property name="lineWrappingIndentation" value="4"/>
+            <property name="arrayInitIndent" value="2"/>
+        </module>
+        <module name="AbbreviationAsWordInName">
+            <property name="ignoreFinal" value="false"/>
+            <property name="allowedAbbreviationLength" value="1"/>
+        </module>
+        <module name="OverloadMethodsDeclarationOrder"/>
+        <module name="VariableDeclarationUsageDistance"/>
+        <module name="CustomImportOrder">
+            <property name="thirdPartyPackageRegExp" value=".*"/>
+            <property name="specialImportsRegExp" value="com.google"/>
+            <property name="sortImportsInGroupAlphabetically" value="true"/>
+            <property name="customImportOrderRules" value="STATIC###SPECIAL_IMPORTS###THIRD_PARTY_PACKAGE###STANDARD_JAVA_PACKAGE"/>
+        </module>
+        <module name="MethodParamPad"/>
+        <module name="OperatorWrap">
+            <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="AnnotationLocation">
+            <property name="tokens" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF"/>
+        </module>
+        <module name="AnnotationLocation">
+            <property name="tokens" value="VARIABLE_DEF"/>
+            <property name="allowSamelineMultipleAnnotations" value="true"/>
+        </module>
+        <module name="NonEmptyAtclauseDescription"/>
+        <module name="JavadocTagContinuationIndentation"/>
+        <module name="SummaryJavadocCheck">
+            <property name="forbiddenSummaryFragments" value="^@return the *|^This method returns |^A [{]@code [a-zA-Z0-9]+[}]( is a )"/>
+        </module>
+        <module name="JavadocParagraph"/>
+        <module name="AtclauseOrder">
+            <property name="tagOrder" value="@param, @return, @throws, @deprecated"/>
+            <property name="target" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF, VARIABLE_DEF"/>
+        </module>
+        <module name="JavadocMethod">
+            <property name="scope" value="public"/>
+            <property name="allowMissingParamTags" value="true"/>
+            <property name="allowMissingThrowsTags" value="true"/>
+            <property name="allowMissingReturnTag" value="true"/>
+            <property name="minLineCount" value="2"/>
+            <property name="allowedAnnotations" value="Override, Test"/>
+            <property name="allowThrowsTagsForSubclasses" value="true"/>
+        </module>
+        <module name="MethodName">
+            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9_]*$"/>
+            <message key="name.invalidPattern"
+                     value="Method name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="SingleLineJavadoc"/>
+    </module>
+</module>
diff --git a/pom.xml b/pom.xml
index 7b0d80bd8..68fd2254e 100644
--- a/pom.xml
+++ b/pom.xml
@@ -1,211 +1,236 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-	<modelVersion>4.0.0</modelVersion>
+<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
 
-	<groupId>com.iluwatar</groupId>
-	<artifactId>java-design-patterns</artifactId>
-	<version>1.6.0</version>
-	<packaging>pom</packaging>
+    <groupId>com.iluwatar</groupId>
+    <artifactId>java-design-patterns</artifactId>
+    <version>1.6.0</version>
+    <packaging>pom</packaging>
 
-	<properties>
-		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<hibernate.version>5.0.0.Final</hibernate.version>
-		<spring-data.version>1.8.2.RELEASE</spring-data.version>
-		<h2.version>1.4.188</h2.version>
-		<junit.version>4.12</junit.version>
-		<compiler.version>3.0</compiler.version>
-		<coveralls.version>3.1.0</coveralls.version>
-		<jacoco.version>0.7.2.201409121644</jacoco.version>
-		<commons-dbcp.version>1.4</commons-dbcp.version>
-		<camel.version>2.15.3</camel.version>
-	</properties>
-	<modules>
-		<module>abstract-factory</module>
-		<module>builder</module>
-		<module>factory-method</module>
-		<module>prototype</module>
-		<module>singleton</module>
-		<module>adapter</module>
-		<module>bridge</module>
-		<module>composite</module>
-		<module>dao</module>
-		<module>decorator</module>
-		<module>facade</module>
-		<module>flyweight</module>
-		<module>proxy</module>
-		<module>chain</module>
-		<module>command</module>
-		<module>interpreter</module>
-		<module>iterator</module>
-		<module>mediator</module>
-		<module>memento</module>
-		<module>model-view-presenter</module>
-		<module>observer</module>
-		<module>state</module>
-		<module>strategy</module>
-		<module>template-method</module>
-		<module>visitor</module>
-		<module>double-checked-locking</module>
-		<module>servant</module>
-		<module>service-locator</module>
-		<module>null-object</module>
-		<module>event-aggregator</module>
-		<module>callback</module>
-		<module>execute-around</module>
-		<module>property</module>
-		<module>intercepting-filter</module>
-		<module>poison-pill</module>
-		<module>lazy-loading</module>
-		<module>service-layer</module>
-		<module>specification</module>
-		<module>tolerant-reader</module>
-		<module>model-view-controller</module>
-		<module>flux</module>
-		<module>double-dispatch</module>
-		<module>multiton</module>
-		<module>resource-acquisition-is-initialization</module>
-		<module>thread-pool</module>
-		<module>private-class-data</module>
-		<module>object-pool</module>
-		<module>dependency-injection</module>
-		<module>naked-objects</module>
-		<module>front-controller</module>
-		<module>repository</module>
-		<module>async-method-invocation</module>
-    	<module>business-delegate</module>
-    	<module>half-sync-half-async</module>
-		<module>step-builder</module>
-		<module>layers</module>
-		<module>message-channel</module>
-  </modules>
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <hibernate.version>5.0.0.Final</hibernate.version>
+        <spring-data.version>1.8.2.RELEASE</spring-data.version>
+        <h2.version>1.4.188</h2.version>
+        <junit.version>4.12</junit.version>
+        <compiler.version>3.0</compiler.version>
+        <coveralls.version>3.1.0</coveralls.version>
+        <jacoco.version>0.7.2.201409121644</jacoco.version>
+        <commons-dbcp.version>1.4</commons-dbcp.version>
+        <camel.version>2.15.3</camel.version>
+    </properties>
+    <modules>
+        <module>abstract-factory</module>
+        <module>builder</module>
+        <module>factory-method</module>
+        <module>prototype</module>
+        <module>singleton</module>
+        <module>adapter</module>
+        <module>bridge</module>
+        <module>composite</module>
+        <module>dao</module>
+        <module>decorator</module>
+        <module>facade</module>
+        <module>flyweight</module>
+        <module>proxy</module>
+        <module>chain</module>
+        <module>command</module>
+        <module>interpreter</module>
+        <module>iterator</module>
+        <module>mediator</module>
+        <module>memento</module>
+        <module>model-view-presenter</module>
+        <module>observer</module>
+        <module>state</module>
+        <module>strategy</module>
+        <module>template-method</module>
+        <module>visitor</module>
+        <module>double-checked-locking</module>
+        <module>servant</module>
+        <module>service-locator</module>
+        <module>null-object</module>
+        <module>event-aggregator</module>
+        <module>callback</module>
+        <module>execute-around</module>
+        <module>property</module>
+        <module>intercepting-filter</module>
+        <module>poison-pill</module>
+        <module>lazy-loading</module>
+        <module>service-layer</module>
+        <module>specification</module>
+        <module>tolerant-reader</module>
+        <module>model-view-controller</module>
+        <module>flux</module>
+        <module>double-dispatch</module>
+        <module>multiton</module>
+        <module>resource-acquisition-is-initialization</module>
+        <module>thread-pool</module>
+        <module>private-class-data</module>
+        <module>object-pool</module>
+        <module>dependency-injection</module>
+        <module>naked-objects</module>
+        <module>front-controller</module>
+        <module>repository</module>
+        <module>async-method-invocation</module>
+        <module>business-delegate</module>
+        <module>half-sync-half-async</module>
+        <module>step-builder</module>
+        <module>layers</module>
+        <module>message-channel</module>
+    </modules>
 
-	<dependencyManagement>
-		<dependencies>
-			<dependency>
-				<groupId>org.hibernate</groupId>
-				<artifactId>hibernate-core</artifactId>
-				<version>${hibernate.version}</version>
-			</dependency>
-			<dependency>
-				<groupId>org.hibernate</groupId>
-				<artifactId>hibernate-entitymanager</artifactId>
-				<version>${hibernate.version}</version>
-			</dependency>
-			<dependency>
-				<groupId>org.springframework.data</groupId>
-				<artifactId>spring-data-jpa</artifactId>
-				<version>${spring-data.version}</version>
-			</dependency>
-			<dependency>
-				<groupId>com.h2database</groupId>
-				<artifactId>h2</artifactId>
-				<version>${h2.version}</version>
-			</dependency>
-			<dependency>
-				<groupId>commons-dbcp</groupId>
-				<artifactId>commons-dbcp</artifactId>
-				<version>${commons-dbcp.version}</version>
-			</dependency>
-			<dependency>
-				<groupId>org.apache.camel</groupId>
-				<artifactId>camel-core</artifactId>
-				<version>${camel.version}</version>
-			</dependency>
-			<dependency>
-				<groupId>org.apache.camel</groupId>
-				<artifactId>camel-stream</artifactId>
-				<version>${camel.version}</version>
-			</dependency>
-			<dependency>
-				<groupId>junit</groupId>
-				<artifactId>junit</artifactId>
-				<version>${junit.version}</version>
-				<scope>test</scope>
-			</dependency>
-		</dependencies>
-	</dependencyManagement>
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.hibernate</groupId>
+                <artifactId>hibernate-core</artifactId>
+                <version>${hibernate.version}</version>
+            </dependency>
+            <dependency>
+                <groupId>org.hibernate</groupId>
+                <artifactId>hibernate-entitymanager</artifactId>
+                <version>${hibernate.version}</version>
+            </dependency>
+            <dependency>
+                <groupId>org.springframework.data</groupId>
+                <artifactId>spring-data-jpa</artifactId>
+                <version>${spring-data.version}</version>
+            </dependency>
+            <dependency>
+                <groupId>com.h2database</groupId>
+                <artifactId>h2</artifactId>
+                <version>${h2.version}</version>
+            </dependency>
+            <dependency>
+                <groupId>commons-dbcp</groupId>
+                <artifactId>commons-dbcp</artifactId>
+                <version>${commons-dbcp.version}</version>
+            </dependency>
+            <dependency>
+                <groupId>org.apache.camel</groupId>
+                <artifactId>camel-core</artifactId>
+                <version>${camel.version}</version>
+            </dependency>
+            <dependency>
+                <groupId>org.apache.camel</groupId>
+                <artifactId>camel-stream</artifactId>
+                <version>${camel.version}</version>
+            </dependency>
+            <dependency>
+                <groupId>junit</groupId>
+                <artifactId>junit</artifactId>
+                <version>${junit.version}</version>
+                <scope>test</scope>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
 
 
-	<build>
-		<pluginManagement>
-			<plugins>
-				<!-- This plugin's configuration is used to store Eclipse m2e settings 
-					only. It has no influence on the Maven build itself. TODO: Remove when the 
-					m2e plugin can correctly bind to Maven lifecycle -->
-				<plugin>
-					<groupId>org.eclipse.m2e</groupId>
-					<artifactId>lifecycle-mapping</artifactId>
-					<version>1.0.0</version>
-					<configuration>
-						<lifecycleMappingMetadata>
-							<pluginExecutions>
-								<pluginExecution>
-									<pluginExecutionFilter>
-										<groupId>org.jacoco</groupId>
-										<artifactId>
-											jacoco-maven-plugin
-										</artifactId>
-										<versionRange>
-											[0.6.2,)
-										</versionRange>
-										<goals>
-											<goal>prepare-agent</goal>
-										</goals>
-									</pluginExecutionFilter>
-									<action>
-										<ignore/>
-									</action>
-								</pluginExecution>
-							</pluginExecutions>
-						</lifecycleMappingMetadata>
-					</configuration>
-				</plugin>
-			</plugins>
-		</pluginManagement>
+    <build>
+        <pluginManagement>
+            <plugins>
+                <!-- This plugin's configuration is used to store Eclipse m2e settings
+                    only. It has no influence on the Maven build itself. TODO: Remove when the
+                    m2e plugin can correctly bind to Maven lifecycle -->
+                <plugin>
+                    <groupId>org.eclipse.m2e</groupId>
+                    <artifactId>lifecycle-mapping</artifactId>
+                    <version>1.0.0</version>
+                    <configuration>
+                        <lifecycleMappingMetadata>
+                            <pluginExecutions>
+                                <pluginExecution>
+                                    <pluginExecutionFilter>
+                                        <groupId>org.jacoco</groupId>
+                                        <artifactId>
+                                            jacoco-maven-plugin
+                                        </artifactId>
+                                        <versionRange>
+                                            [0.6.2,)
+                                        </versionRange>
+                                        <goals>
+                                            <goal>prepare-agent</goal>
+                                        </goals>
+                                    </pluginExecutionFilter>
+                                    <action>
+                                        <ignore/>
+                                    </action>
+                                </pluginExecution>
+                            </pluginExecutions>
+                        </lifecycleMappingMetadata>
+                    </configuration>
+                </plugin>
+            </plugins>
+        </pluginManagement>
 
-		<plugins>
-			<!-- Tell maven to compile using Java 8 -->
-			<plugin>
-				<groupId>org.apache.maven.plugins</groupId>
-				<artifactId>maven-compiler-plugin</artifactId>
-				<version>${compiler.version}</version>
-				<configuration>
-					<source>1.8</source>
-					<target>1.8</target>
-				</configuration>
-			</plugin>
-			<plugin>
-				<groupId>org.eluder.coveralls</groupId>
-				<artifactId>coveralls-maven-plugin</artifactId>
-				<version>${coveralls.version}</version>
-				<configuration>
-					<repoToken>jb6wYzxkVvjolD6qOWpzWdcWBzYk2fAmF</repoToken>
-				</configuration>
-			</plugin>
-			<plugin>
-				<groupId>org.jacoco</groupId>
-				<artifactId>jacoco-maven-plugin</artifactId>
-				<version>${jacoco.version}</version>
-				<!-- The following exclude configuration was added because error occurred 
-					when executing "mvn clean test jacoco:report coveralls:report" -->
-				<!-- [ERROR] Failed to execute goal org.eluder.coveralls:coveralls-maven-plugin:3.1.0:report 
-					(default-cli) on project java-design-patterns: I/O operation failed: No source 
-					found for domainapp/dom/modules/simple/QSimpleObject.java -> [Help 1] -->
-				<configuration>
-					<excludes>
-						<exclude>domainapp/dom/modules/simple/QSimpleObject.class</exclude>
-					</excludes>
-				</configuration>
-				<executions>
-					<execution>
-						<id>prepare-agent</id>
-						<goals>
-							<goal>prepare-agent</goal>
-						</goals>
-					</execution>
-				</executions>
-			</plugin>
-		</plugins>
-	</build>
+        <plugins>
+            <!-- Tell maven to compile using Java 8 -->
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>${compiler.version}</version>
+                <configuration>
+                    <source>1.8</source>
+                    <target>1.8</target>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.eluder.coveralls</groupId>
+                <artifactId>coveralls-maven-plugin</artifactId>
+                <version>${coveralls.version}</version>
+                <configuration>
+                    <repoToken>jb6wYzxkVvjolD6qOWpzWdcWBzYk2fAmF</repoToken>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.jacoco</groupId>
+                <artifactId>jacoco-maven-plugin</artifactId>
+                <version>${jacoco.version}</version>
+                <!-- The following exclude configuration was added because error occurred
+                    when executing "mvn clean test jacoco:report coveralls:report" -->
+                <!-- [ERROR] Failed to execute goal org.eluder.coveralls:coveralls-maven-plugin:3.1.0:report
+                    (default-cli) on project java-design-patterns: I/O operation failed: No source
+                    found for domainapp/dom/modules/simple/QSimpleObject.java -> [Help 1] -->
+                <configuration>
+                    <excludes>
+                        <exclude>domainapp/dom/modules/simple/QSimpleObject.class</exclude>
+                    </excludes>
+                </configuration>
+                <executions>
+                    <execution>
+                        <id>prepare-agent</id>
+                        <goals>
+                            <goal>prepare-agent</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
 
-</project>
\ No newline at end of file
+            <!--checkstyle plug-in. checking against googles styles
+               see config at checkstyle.xml
+            -->
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-checkstyle-plugin</artifactId>
+                <version>2.15</version>
+                <executions>
+                    <execution>
+                        <id>validate</id>
+                        <goals>
+                            <goal>check</goal>
+                        </goals>
+                        <phase>validate</phase>
+                        <configuration>
+                            <configLocation>checkstyle.xml</configLocation>
+                            <encoding>UTF-8</encoding>
+                            <consoleOutput>true</consoleOutput>
+                            <failsOnError>false</failsOnError>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>