checkstyle.xml

<?xml version="1.0"?>
<!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.2//EN" "http://www.puppycrawl.com/dtds/configuration_1_2.dtd">
<module name="Checker">
  <module name="NewlineAtEndOfFile">
    <property name="lineSeparator" value="lf"/>
  </module>
  <!-- Trailing spaces -->
  <module name="RegexpSingleline">
    <property name="format" value="\s+$"/>
    <property name="message" value="Line has trailing spaces."/>
  </module>

  <!-- Checks for the new line format -->
  <module name="RegexpMultiline">
    <property name="format" value="\r\n"/>
    <property name="message" value="Do not use Windows line endings"/>
  </module>

  <module name="TreeWalker">
    <module name="RegexpSinglelineJava">
      <property name="format" value="^\t* "/>
      <property name="message" value="Indent must use tab characters"/>
      <property name="ignoreComments" value="true"/>
    </module>

    <!-- Checks for imports                              -->
    <!-- See http://checkstyle.sf.net/config_import.html -->
    <module name="AvoidStarImport"/>
    <module name="IllegalImport"/> <!-- defaults to sun.* packages -->
    <module name="RedundantImport"/>
    <module name="IllegalImport">
      <property name="regexp" value="true" />
      <property name="illegalClasses" value="^(?!.*(spoon|jdt)).*internal.*$" />
      <!--The regex looks for imports containing internal and not containing spoon or jdt. Some examples are:
      import spoon.pattern.internal.node.ForEachNode; // allowed because internal package but from spoon.
      import org.eclipse.jdt.internal.compiler.batch.CompilationUnit; //allowed because internal package but from jdt.
      import org.apache.commons.jexl2.internal.introspection; //rejected because import of internal package -->
    </module>
    <module name="UnusedImports">
      <property name="processJavadoc" value="true"/>
    </module>

    <!-- Checks for whitespace                               -->
    <!-- See http://checkstyle.sf.net/config_whitespace.html -->
    <module name="GenericWhitespace"/>
    <module name="EmptyForIteratorPad"/>
    <module name="MethodParamPad"/>
    <module name="NoWhitespaceAfter">
      <property name="tokens" value="BNOT, DEC, DOT, INC, LNOT, UNARY_MINUS, UNARY_PLUS"/>
    </module>
    <module name="NoWhitespaceBefore"/>
    <module name="OperatorWrap"/>
    <module name="ParenPad"/>
    <module name="WhitespaceAfter"/>
    <module name="WhitespaceAround"/>

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

    <!-- Checks for blocks. You know, those {}'s         -->
    <!-- See http://checkstyle.sf.net/config_blocks.html -->
    <module name="LeftCurly" >
    	<property name="tokens" value="ANNOTATION_DEF, CLASS_DEF, CTOR_DEF, ENUM_CONSTANT_DEF, ENUM_DEF, INTERFACE_DEF, LITERAL_CATCH, LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY, LITERAL_FOR, LITERAL_IF, LITERAL_SWITCH, LITERAL_SYNCHRONIZED, LITERAL_TRY, LITERAL_WHILE, METHOD_DEF, OBJBLOCK, STATIC_INIT"/>
    </module>
    <module name="RightCurly" />
    <module name="NeedBraces"/>

    <!-- Checks for class design                         -->
    <!-- See http://checkstyle.sf.net/config_design.html -->
    <module name="InterfaceIsType"/>
    <module name="HideUtilityClassConstructor"/>
  </module>
</module>