Checkstyle.xml

<?xml version="1.0"?>
<!DOCTYPE module PUBLIC
          "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
          "https://checkstyle.org/dtds/configuration_1_3.dtd">

<module name = "Checker">
    <!-- Credit to the CS 1332 team for the basis of this checkstyle
    configuration file -->

    <!-- ! Make sure you are using Checkstyle 8.24 for this file ! -->
    <property name="charset" value="UTF-8"/>
    <property name="severity" value="warning"/>

    <!-- Whitespace checks -->
    <module name="FileTabCharacter">
        <property name="eachLine" 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="TreeWalker">
        <!-- Checks for Naming Conventions.                  -->
        <!-- See http://checkstyle.sf.net/config_naming.html -->
        <module name="ConstantName"/>
        <module name="LocalFinalVariableName"/>
        <module name="LocalVariableName"/>
        <module name="MemberName"/>
        <module name="MethodName"/>
        <module name="PackageName"/>
        <module name="ParameterName"/>
        <module name="StaticVariableName"/>
        <module name="TypeName"/>

        <!-- Checks for imports                              -->
        <!-- See http://checkstyle.sf.net/config_import.html -->
        <module name="IllegalImport"/> <!-- defaults to sun.* packages -->
        <module name="RedundantImport"/>
        <module name="UnusedImports"/>

        <!-- Checks for Size Violations.                    -->
        <!-- See http://checkstyle.sf.net/config_sizes.html -->
        <module name="MethodLength"/>
        <module name="ParameterNumber"/>

        <!-- Checks for whitespace                               -->
        <!-- See http://checkstyle.sf.net/config_whitespace.html -->
        <module name="EmptyForIteratorPad"/>
        <module name="GenericWhitespace"/>
        <module name="MethodParamPad"/>
        <module name="NoWhitespaceAfter"/>
        <module name="NoWhitespaceBefore"/>
        <module name="OperatorWrap"/>
        <module name="ParenPad"/>
        <module name="TypecastParenPad"/>
        <module name="WhitespaceAfter"/>
        <module name="WhitespaceAround"/>

        <!-- Modifier Checks                                    -->
        <!-- See http://checkstyle.sf.net/config_modifiers.html -->
        <module name="ModifierOrder"/>

        <!-- Checks for blocks. You know, those {}'s         -->
        <!-- See http://checkstyle.sf.net/config_blocks.html -->
        <module name="AvoidNestedBlocks"/>
        <module name="EmptyBlock"/>
        <module name="LeftCurly"/>
        <module name="NeedBraces"/>
        <module name="RightCurly"/>

        <!-- Checks for common coding problems               -->
        <!-- See http://checkstyle.sf.net/config_coding.html -->
        <module name="EmptyStatement"/>
        <module name="IllegalInstantiation"/>
        <module name="InnerAssignment"/>

        <module name="MissingSwitchDefault"/>
        <module name="FallThrough"/>
        <module name="SimplifyBooleanExpression"/>
        <module name="SimplifyBooleanReturn"/>

        <module name="MultipleVariableDeclarations"/>
        <module name="AbbreviationAsWordInName"/>

        <!-- Javadoc checks.                              -->
        <module name="JavadocMethod">
            <property name="allowUndeclaredRTE" value="true"/>
            <property name="allowedAnnotations" value="Override, Test, Before, After, BeforeClass, AfterClass"/>
        </module>
        <module name="JavadocStyle">
            <property name="checkFirstSentence" value="false"/>
        </module>
        <module name="NonEmptyAtclauseDescription"/>

        <!-- Checks for class design                         -->
        <!-- See http://checkstyle.sf.net/config_design.html -->
        <module name="VisibilityModifier">
          <property name="protectedAllowed" value="true"/>
        </module>

        <!-- Miscellaneous other checks.                   -->
        <!-- See http://checkstyle.sf.net/config_misc.html -->
        <module name="ArrayTypeStyle"/>
        <module name="TodoComment"/>
        <module name="UpperEll"/>
        <module name="Indentation">
          <property name="caseIndent" value="0"/>
        </module>
        <module name="DefaultComesLast"/>
        <module name="OneStatementPerLine"/>
        <module name="InnerTypeLast"/>
        <module name="OneTopLevelClass"/>
        <module name="CommentsIndentationCheck"/>
    </module>
</module>