checkstyle_base.xml

<?xml version="1.0" standalone="yes"?>
<!DOCTYPE module [
    <!ELEMENT module (module|property|metadata|message)*>
    <!ATTLIST module name NMTOKEN #REQUIRED>
    <!ELEMENT property EMPTY>
    <!ATTLIST property
        name NMTOKEN #REQUIRED
        value CDATA #REQUIRED
        default CDATA #IMPLIED
    >
    <!ELEMENT metadata EMPTY>
    <!ATTLIST metadata
        name NMTOKEN #REQUIRED
        value CDATA #REQUIRED
    >
    <!ELEMENT message EMPTY>
    <!ATTLIST message
        key NMTOKEN #REQUIRED
        value CDATA #REQUIRED
    >
]>

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

    <property name="fileExtensions" value="java"/>
    <!-- Checks for whitespace                               -->
    <!-- See http://checkstyle.sf.net/config_whitespace.html -->

    <module name="TreeWalker">

    	<property name="tabWidth" value="4"/>

    	<!-- File should be named as the class -->
        <module name="OuterTypeFilename"/>

        <!-- Only one class per File -->
        <module name="OneTopLevelClass"/>

        <!--  no lines longer than 150 chars -->
        <module name="LineLength">
            <property name="max" value="150"/>
            <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
        </module>

        <!-- No escaped Strings and Chars -->
        <module name="IllegalTokenText">
            <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL"/>
            <property name="format"
             value="\\u00(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="Consider using special escape sequence instead of octal value or Unicode escaped value."/>
        </module>
        <module name="AvoidEscapedUnicodeCharacters">
            <property name="allowEscapesForControlCharacters" value="true"/>
            <property name="allowByTailComment" value="true"/>
            <property name="allowNonPrintableEscapes" value="true"/>
        </module>

		<!-- We want explicit imports -->
        <module name="AvoidStarImport"/>
        <module name="IllegalImport"/> <!-- defaults to sun.* packages -->
        <module name="RedundantImport"/>
		<module name="UnusedImports"/>

		<!-- We do not want to have things like method declarations or imports to be line wrapped -->
        <module name="NoLineWrap"/>

        <!-- Empty blocks are useless -->
        <module name="EmptyBlock">
            <property name="option" value="TEXT"/>
            <property name="tokens"
             value="LITERAL_TRY, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_SWITCH"/>
        </module>

        <!-- no Spaghetti code -->
        <module name="OneStatementPerLine"/>

        <!-- Switches should have a default  -->
        <module name="MissingSwitchDefault"/>

        <!-- Fallthroughs are potentially dangerous -->
        <module name="FallThrough"/>

		<!-- If there is something to do -> do it ! -->
        <module name="TodoComment"/>

        <!-- We want to have our code structured, so we want empty lines between line separators,
        after header, package, all import declarations, fields, constructors, methods,
        nested classes, static initializers and instance initializers -->
        <module name="EmptyLineSeparator">
            <property name="allowNoEmptyLineBetweenFields" value="true"/>
        </module>


        <!-- There should be a space between method parameters -->
        <module name="MethodParamPad"/>

        <!-- There should be no spaces between the names tokens -->
        <module name="NoWhitespaceBefore">
            <property name="tokens"
             value="COMMA, SEMI, POST_INC, POST_DEC, DOT"/>
            <property name="allowLineBreaks" value="true"/>
        </module>

        <!-- No passing in between parantheses -->
        <module name="ParenPad">
        	<property name="option" value="nospace"/>
        </module>

        <!-- No line wrap at these tokens -->
        <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>

        <!-- Empty catch blocks are trying to hide something ! -->
        <module name="EmptyCatchBlock">
            <property name="exceptionVariableName" value="expected"/>
        </module>

        <!-- Generics do not need whitespaces -->
        <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>

        <!-- Comments should be intended as the thing that they are commenting -->
        <module name="CommentsIndentation"/>

        <!-- General intendation - unsure if needed  -->
        <module name="Indentation">
            <property name="basicOffset" value="4"/>
            <property name="braceAdjustment" value="0"/>
        </module>

    </module>
</module>