diff --git a/config/pmd.xml b/config/pmd.xml
new file mode 100644
index 0000000..547f745
--- /dev/null
+++ b/config/pmd.xml
@@ -0,0 +1,253 @@
+<?xml version="1.0"?>
+<ruleset name="erik"
+         xmlns="http://pmd.sourceforge.net/ruleset/2.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://pmd.sourceforge.net/ruleset/2.0.0 https://pmd.sourceforge.io/ruleset_2_0_0.xsd">
+    <description>Erik's Ruleset</description>
+    <rule ref="category/java/bestpractices.xml/AvoidStringBufferField"/>
+    <rule ref="category/java/bestpractices.xml/AvoidUsingHardCodedIP"/>
+    <rule ref="category/java/bestpractices.xml/CheckResultSet"/>
+    <rule ref="category/java/bestpractices.xml/ConstantsInInterface"/>
+    <rule ref="category/java/bestpractices.xml/DefaultLabelNotLastInSwitchStmt"/>
+    <rule ref="category/java/bestpractices.xml/ForLoopCanBeForeach"/>
+    <rule ref="category/java/bestpractices.xml/GuardLogStatement"/>
+    <rule ref="category/java/bestpractices.xml/LooseCoupling"/>
+    <rule ref="category/java/bestpractices.xml/MethodReturnsInternalArray"/>
+    <rule ref="category/java/bestpractices.xml/MissingOverride"/>
+    <rule ref="category/java/bestpractices.xml/PositionLiteralsFirstInCaseInsensitiveComparisons"/>
+    <rule ref="category/java/bestpractices.xml/PositionLiteralsFirstInComparisons"/>
+    <rule ref="category/java/bestpractices.xml/PreserveStackTrace"/>
+    <rule ref="category/java/bestpractices.xml/ReplaceEnumerationWithIterator"/>
+    <rule ref="category/java/bestpractices.xml/ReplaceHashtableWithMap"/>
+    <rule ref="category/java/bestpractices.xml/ReplaceVectorWithList"/>
+    <rule ref="category/java/bestpractices.xml/SwitchStmtsShouldHaveDefault"/>
+    <rule ref="category/java/bestpractices.xml/SystemPrintln"/>
+    <rule ref="category/java/bestpractices.xml/UnusedFormalParameter"/>
+    <rule ref="category/java/bestpractices.xml/UnusedImports"/>
+    <rule ref="category/java/bestpractices.xml/UnusedLocalVariable"/>
+    <rule ref="category/java/bestpractices.xml/UnusedPrivateField"/>
+    <rule ref="category/java/bestpractices.xml/UnusedPrivateMethod"/>
+    <rule ref="category/java/bestpractices.xml/UseAssertEqualsInsteadOfAssertTrue"/>
+    <rule ref="category/java/bestpractices.xml/UseAssertNullInsteadOfAssertTrue"/>
+    <rule ref="category/java/bestpractices.xml/UseAssertSameInsteadOfAssertTrue"/>
+    <rule ref="category/java/bestpractices.xml/UseAssertTrueInsteadOfAssertEquals"/>
+    <rule ref="category/java/bestpractices.xml/UseCollectionIsEmpty"/>
+    <rule ref="category/java/bestpractices.xml/UseVarargs"/>
+
+
+    <!-- NAMING CONVENTIONS -->
+    <rule ref="category/java/codestyle.xml/FormalParameterNamingConventions"/>
+    <rule ref="category/java/codestyle.xml/GenericsNaming"/>
+    <rule ref="category/java/codestyle.xml/LocalVariableNamingConventions"/>
+    <rule ref="category/java/codestyle.xml/MethodNamingConventions"/>
+    <rule ref="category/java/codestyle.xml/PackageCase"/>
+
+
+    <!-- OTHER -->
+    <rule ref="category/java/codestyle.xml/AvoidDollarSigns"/>
+    <rule ref="category/java/codestyle.xml/AvoidProtectedFieldInFinalClass"/>
+    <rule ref="category/java/codestyle.xml/AvoidProtectedMethodInFinalClassNotExtending"/>
+    <rule ref="category/java/codestyle.xml/AvoidUsingNativeCode"/>
+    <rule ref="category/java/codestyle.xml/BooleanGetMethodName"/>
+    <rule ref="category/java/codestyle.xml/CallSuperInConstructor"/>
+    <rule ref="category/java/codestyle.xml/ControlStatementBraces"/>
+    <rule ref="category/java/codestyle.xml/DontImportJavaLang"/>
+    <rule ref="category/java/codestyle.xml/DuplicateImports"/>
+    <rule ref="category/java/codestyle.xml/EmptyMethodInAbstractClassShouldBeAbstract"/>
+    <rule ref="category/java/codestyle.xml/ExtendsObject"/>
+    <rule ref="category/java/codestyle.xml/FieldDeclarationsShouldBeAtStartOfClass"/>
+    <rule ref="category/java/codestyle.xml/ForLoopShouldBeWhileLoop"/>
+    <rule ref="category/java/codestyle.xml/IdenticalCatchBranches"/>
+    <rule ref="category/java/codestyle.xml/LocalVariableCouldBeFinal"/>
+    <rule ref="category/java/codestyle.xml/MethodArgumentCouldBeFinal"/>
+    <rule ref="category/java/codestyle.xml/NoPackage"/>
+    <rule ref="category/java/codestyle.xml/PrematureDeclaration"/>
+    <rule ref="category/java/codestyle.xml/TooManyStaticImports"/>
+    <rule ref="category/java/codestyle.xml/UnnecessaryAnnotationValueElement"/>
+    <rule ref="category/java/codestyle.xml/UnnecessaryConstructor"/>
+    <rule ref="category/java/codestyle.xml/UnnecessaryFullyQualifiedName"/>
+    <rule ref="category/java/codestyle.xml/UnnecessaryLocalBeforeReturn"/>
+    <rule ref="category/java/codestyle.xml/UnnecessaryReturn"/>
+    <rule ref="category/java/codestyle.xml/UselessQualifiedThis"/>
+
+
+    <!-- DESIGN -->
+    <rule ref="category/java/design.xml/AbstractClassWithoutAnyMethod"/>
+    <rule ref="category/java/design.xml/AvoidRethrowingException"/>
+    <rule ref="category/java/design.xml/AvoidThrowingNewInstanceOfSameException"/>
+    <rule ref="category/java/design.xml/AvoidThrowingNullPointerException"/>
+    <rule ref="category/java/design.xml/AvoidThrowingRawExceptionTypes"/>
+    <rule ref="category/java/design.xml/ClassWithOnlyPrivateConstructorsShouldBeFinal"/>
+    <rule ref="category/java/design.xml/CollapsibleIfStatements"/>
+    <rule ref="category/java/design.xml/CouplingBetweenObjects"/>
+    <rule ref="category/java/design.xml/DataClass"/>
+    <rule ref="category/java/design.xml/DoNotExtendJavaLangError"/>
+    <rule ref="category/java/design.xml/ExceptionAsFlowControl"/>
+    <rule ref="category/java/design.xml/ExcessivePublicCount"/>
+    <rule ref="category/java/design.xml/FinalFieldCouldBeStatic"/>
+    <rule ref="category/java/design.xml/ImmutableField"/>
+    <rule ref="category/java/design.xml/LogicInversion"/>
+    <rule ref="category/java/design.xml/SignatureDeclareThrowsException"/>
+    <rule ref="category/java/design.xml/SimplifiedTernary"/>
+    <rule ref="category/java/design.xml/SimplifyBooleanAssertion"/>
+    <rule ref="category/java/design.xml/SimplifyBooleanExpressions"/>
+    <rule ref="category/java/design.xml/SimplifyBooleanReturns"/>
+    <rule ref="category/java/design.xml/SimplifyConditional"/>
+    <rule ref="category/java/design.xml/SingularField"/>
+    <rule ref="category/java/design.xml/SwitchDensity"/>
+    <rule ref="category/java/design.xml/UselessOverridingMethod"/>
+    <rule ref="category/java/design.xml/UseUtilityClass"/>
+
+    <!-- DOCUMENTATION -->
+    <rule ref="category/java/documentation.xml/UncommentedEmptyConstructor"/>
+    <rule ref="category/java/documentation.xml/UncommentedEmptyMethodBody"/>
+
+
+    <!-- ERRORPRONE -->
+    <rule ref="category/java/errorprone.xml/AssignmentInOperand">
+        <properties>
+            <property name="allowWhile" value="true"/>
+        </properties>
+    </rule>
+    <rule ref="category/java/errorprone.xml/AssignmentToNonFinalStatic"/>
+    <rule ref="category/java/errorprone.xml/AvoidAccessibilityAlteration"/>
+    <rule ref="category/java/errorprone.xml/AvoidAssertAsIdentifier"/>
+    <rule ref="category/java/errorprone.xml/AvoidBranchingStatementAsLastInLoop"/>
+    <rule ref="category/java/errorprone.xml/AvoidCallingFinalize"/>
+    <rule ref="category/java/errorprone.xml/AvoidCatchingThrowable"/>
+    <rule ref="category/java/errorprone.xml/AvoidDecimalLiteralsInBigDecimalConstructor"/>
+    <rule ref="category/java/errorprone.xml/AvoidDuplicateLiterals"/>
+    <rule ref="category/java/errorprone.xml/AvoidEnumAsIdentifier"/>
+    <rule ref="category/java/errorprone.xml/AvoidInstanceofChecksInCatchClause"/>
+    <rule ref="category/java/errorprone.xml/AvoidLosingExceptionInformation"/>
+    <rule ref="category/java/errorprone.xml/AvoidMultipleUnaryOperators"/>
+    <rule ref="category/java/errorprone.xml/AvoidUsingOctalValues"/>
+    <rule ref="category/java/errorprone.xml/BadComparison"/>
+    <rule ref="category/java/errorprone.xml/BrokenNullCheck"/>
+    <rule ref="category/java/errorprone.xml/CallSuperFirst"/>
+    <rule ref="category/java/errorprone.xml/CallSuperLast"/>
+    <rule ref="category/java/errorprone.xml/CheckSkipResult"/>
+    <rule ref="category/java/errorprone.xml/ClassCastExceptionWithToArray"/>
+    <rule ref="category/java/errorprone.xml/CloneMethodMustBePublic"/>
+    <rule ref="category/java/errorprone.xml/CloneMethodMustImplementCloneable"/>
+    <rule ref="category/java/errorprone.xml/CloneMethodReturnTypeMustMatchClassName"/>
+    <rule ref="category/java/errorprone.xml/CloneThrowsCloneNotSupportedException"/>
+    <rule ref="category/java/errorprone.xml/CloseResource"/>
+    <rule ref="category/java/errorprone.xml/CompareObjectsWithEquals"/>
+    <rule ref="category/java/errorprone.xml/ConstructorCallsOverridableMethod"/>>
+    <rule ref="category/java/errorprone.xml/DoNotCallGarbageCollectionExplicitly"/>
+    <rule ref="category/java/errorprone.xml/DoNotExtendJavaLangThrowable"/>
+    <rule ref="category/java/errorprone.xml/DoNotHardCodeSDCard"/>
+    <rule ref="category/java/errorprone.xml/DoNotThrowExceptionInFinally"/>
+    <rule ref="category/java/errorprone.xml/DontImportSun"/>
+    <rule ref="category/java/errorprone.xml/DontUseFloatTypeForLoopIndices"/>
+    <rule ref="category/java/errorprone.xml/EqualsNull"/>
+    <rule ref="category/java/errorprone.xml/FinalizeDoesNotCallSuperFinalize"/>
+    <rule ref="category/java/errorprone.xml/FinalizeOnlyCallsSuperFinalize"/>
+    <rule ref="category/java/errorprone.xml/FinalizeOverloaded"/>
+    <rule ref="category/java/errorprone.xml/FinalizeShouldBeProtected"/>
+    <rule ref="category/java/errorprone.xml/IdempotentOperations"/>
+    <rule ref="category/java/errorprone.xml/ImportFromSamePackage"/>
+    <rule ref="category/java/errorprone.xml/InstantiationToGetClass"/>
+    <rule ref="category/java/errorprone.xml/InvalidSlf4jMessageFormat"/>
+    <rule ref="category/java/errorprone.xml/JumbledIncrementer"/>
+    <rule ref="category/java/errorprone.xml/JUnitSpelling"/>
+    <rule ref="category/java/errorprone.xml/JUnitStaticSuite"/>
+    <rule ref="category/java/errorprone.xml/LoggerIsNotStaticFinal"/>
+    <rule ref="category/java/errorprone.xml/MethodWithSameNameAsEnclosingClass"/>
+    <rule ref="category/java/errorprone.xml/MisplacedNullCheck"/>
+    <rule ref="category/java/errorprone.xml/MissingBreakInSwitch"/>
+    <rule ref="category/java/errorprone.xml/MissingSerialVersionUID"/>
+    <rule ref="category/java/errorprone.xml/MissingStaticMethodInNonInstantiatableClass"/>
+    <rule ref="category/java/errorprone.xml/MoreThanOneLogger"/>
+    <rule ref="category/java/errorprone.xml/NonCaseLabelInSwitchStatement"/>
+    <rule ref="category/java/errorprone.xml/NonStaticInitializer"/>
+    <rule ref="category/java/errorprone.xml/NullAssignment"/>
+    <rule ref="category/java/errorprone.xml/OverrideBothEqualsAndHashcode"/>
+    <rule ref="category/java/errorprone.xml/ProperCloneImplementation"/>
+    <rule ref="category/java/errorprone.xml/ProperLogger"/>
+    <rule ref="category/java/errorprone.xml/ReturnEmptyArrayRatherThanNull"/>
+    <rule ref="category/java/errorprone.xml/ReturnFromFinallyBlock"/>
+    <rule ref="category/java/errorprone.xml/SimpleDateFormatNeedsLocale"/>
+    <rule ref="category/java/errorprone.xml/SingleMethodSingleton"/>
+    <rule ref="category/java/errorprone.xml/SingletonClassReturningNewInstance"/>
+    <rule ref="category/java/errorprone.xml/StaticEJBFieldShouldBeFinal"/>
+    <rule ref="category/java/errorprone.xml/StringBufferInstantiationWithChar"/>
+    <rule ref="category/java/errorprone.xml/SuspiciousEqualsMethodName"/>
+    <rule ref="category/java/errorprone.xml/SuspiciousHashcodeMethodName"/>
+    <rule ref="category/java/errorprone.xml/SuspiciousOctalEscape"/>
+    <rule ref="category/java/errorprone.xml/TestClassWithoutTestCases"/>
+    <rule ref="category/java/errorprone.xml/UnconditionalIfStatement"/>
+    <rule ref="category/java/errorprone.xml/UnnecessaryBooleanAssertion"/>
+    <rule ref="category/java/errorprone.xml/UnnecessaryCaseChange"/>
+    <rule ref="category/java/errorprone.xml/UnnecessaryConversionTemporary"/>
+    <rule ref="category/java/errorprone.xml/UnusedNullCheckInEquals"/>
+    <rule ref="category/java/errorprone.xml/UseCorrectExceptionLogging"/>
+    <rule ref="category/java/errorprone.xml/UseEqualsToCompareStrings"/>
+    <rule ref="category/java/errorprone.xml/UselessOperationOnImmutable"/>
+    <rule ref="category/java/errorprone.xml/UseLocaleWithCaseConversions"/>
+    <rule ref="category/java/errorprone.xml/EmptyCatchBlock">
+        <properties>
+            <property name="allowExceptionNameRegex">
+                <value>^ignore$</value>
+            </property>
+        </properties>
+    </rule>
+    <rule ref="category/java/errorprone.xml/EmptyFinalizer"/>
+    <rule ref="category/java/errorprone.xml/EmptyFinallyBlock"/>
+    <rule ref="category/java/errorprone.xml/EmptyIfStmt"/>
+    <rule ref="category/java/errorprone.xml/EmptyInitializer"/>
+    <rule ref="category/java/errorprone.xml/EmptyStatementBlock"/>
+    <rule ref="category/java/errorprone.xml/EmptyStatementNotInLoop"/>
+    <rule ref="category/java/errorprone.xml/EmptySwitchStatements"/>
+    <rule ref="category/java/errorprone.xml/EmptySynchronizedBlock"/>
+    <rule ref="category/java/errorprone.xml/EmptyTryBlock"/>
+    <rule ref="category/java/errorprone.xml/EmptyWhileStmt"/>
+
+
+    <!-- MULTITHREADING -->
+    <rule ref="category/java/multithreading.xml/AvoidSynchronizedAtMethodLevel"/>
+    <rule ref="category/java/multithreading.xml/AvoidThreadGroup"/>
+    <rule ref="category/java/multithreading.xml/AvoidUsingVolatile"/>
+    <rule ref="category/java/multithreading.xml/DontCallThreadRun"/>
+    <rule ref="category/java/multithreading.xml/DoubleCheckedLocking"/>
+    <rule ref="category/java/multithreading.xml/NonThreadSafeSingleton"/>
+    <rule ref="category/java/multithreading.xml/UseConcurrentHashMap"/>
+    <rule ref="category/java/multithreading.xml/UseNotifyAllInsteadOfNotify"/>
+
+    <!-- PERFORMANCE -->
+    <rule ref="category/java/performance.xml/AddEmptyString"/>
+    <rule ref="category/java/performance.xml/AppendCharacterWithChar"/>
+    <rule ref="category/java/performance.xml/AvoidArrayLoops"/>
+    <rule ref="category/java/performance.xml/AvoidFileStream"/>
+    <rule ref="category/java/performance.xml/AvoidInstantiatingObjectsInLoops"/>
+    <rule ref="category/java/performance.xml/AvoidUsingShortType"/>
+    <rule ref="category/java/performance.xml/BigIntegerInstantiation"/>
+    <rule ref="category/java/performance.xml/BooleanInstantiation"/>
+    <rule ref="category/java/performance.xml/ByteInstantiation"/>
+    <rule ref="category/java/performance.xml/ConsecutiveAppendsShouldReuse"/>
+    <rule ref="category/java/performance.xml/ConsecutiveLiteralAppends"/>
+    <rule ref="category/java/performance.xml/InefficientEmptyStringCheck"/>
+    <rule ref="category/java/performance.xml/InefficientStringBuffering"/>
+    <rule ref="category/java/performance.xml/InsufficientStringBufferDeclaration"/>
+    <rule ref="category/java/performance.xml/IntegerInstantiation"/>
+    <rule ref="category/java/performance.xml/LongInstantiation"/>
+    <rule ref="category/java/performance.xml/OptimizableToArrayCall"/>
+    <rule ref="category/java/performance.xml/RedundantFieldInitializer"/>
+    <rule ref="category/java/performance.xml/SimplifyStartsWith"/>
+    <rule ref="category/java/performance.xml/ShortInstantiation"/>
+    <rule ref="category/java/performance.xml/StringInstantiation"/>
+    <rule ref="category/java/performance.xml/StringToString"/>
+    <rule ref="category/java/performance.xml/TooFewBranchesForASwitchStatement"/>
+    <rule ref="category/java/performance.xml/UnnecessaryWrapperObjectCreation"/>
+    <rule ref="category/java/performance.xml/UseArrayListInsteadOfVector"/>
+    <rule ref="category/java/performance.xml/UseArraysAsList"/>
+    <rule ref="category/java/performance.xml/UseIndexOfChar"/>
+    <rule ref="category/java/performance.xml/UselessStringValueOf"/>
+    <rule ref="category/java/performance.xml/UseStringBufferForStringAppends"/>
+    <rule ref="category/java/performance.xml/UseStringBufferLength"/>
+
+    <!-- SECURITY -->
+    <rule ref="category/java/security.xml/HardCodedCryptoKey"/>
+    <rule ref="category/java/security.xml/InsecureCryptoIv"/>
+</ruleset>