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">
    <property name="severity" value="warning"/>
    <property name="charset" value="UTF-8"/>

    <!-- No tab characters -->
    <module name="FileTabCharacter"/>

    <!-- Line length: 80 characters -->
    <module name="LineLength">
        <property name="max" value="80"/>
        <property name="ignorePattern"
                  value="^package.*|^import.*|a href|href|http://|https://"/>
    </module>

    <module name="TreeWalker">

        <!-- Require braces, but allow single-line statements -->
        <module name="NeedBraces">
            <property name="allowSingleLineStatement" value="true"/>
        </module>

        <!-- Left curly brace on new line (Allman) -->
        <module name="LeftCurly">
            <property name="option" value="nl"/>
        </module>

        <!-- Right curly brace alone on its own line -->
        <module name="RightCurly">
            <property name="option" value="alone"/>
        </module>

        <!-- Indentation -->
        <module name="Indentation">
            <property name="basicOffset" value="4"/>
            <property name="braceAdjustment" value="0"/>
            <property name="caseIndent" value="4"/>
            <property name="throwsIndent" value="4"/>
            <property name="lineWrappingIndentation" value="8"/>
        </module>

        <!-- Operators wrap to beginning of next line -->
        <module name="OperatorWrap">
            <property name="option" value="nl"/>
        </module>

    </module>
</module>