Property Types

Checkstyle is configured using properties, which are string representations. This document describes how these string representations are mapped to typed properties.

Integer

This property represents an integer. The string representation is parsed using the java.lang.Integer class.

String

This property represents a string. The literal string representation is used.

Boolean

This property represents a boolean. The default value is false. The following string representations will map to true:

Anything else will map to false.

String Set

This property represents a set of strings. The string representation is parsed as a set of comma (',') separated strings.

Integer Set

This property represents a set of integers. The string representation is parsed as a set of comma (',') separated integers that are parsed using the java.lang.Integer class.

Regular Expression

This property represents a regular expression. The string representation is parsed using the excellent Jakarta Regexp library.

Pad Parenthesis Policy

This property represents the policy for padding parenthesises. The following table describes the valid options:

Option Definition
ignore Ignore the padding.
nospace Do not pad. For example, method(a, b);
space Ensure padding. For example, method( a, b );

Operator Wrap Policy

This property represents the policy for wrapping lines on operators. The following table describes the valid options:

Option Definition
ignore Ignore wrapping on an operator.
nl The operator must be on a new line. For example: 
    someVariable = aBigVariableNameToMakeThings + "this may work"
                   + lookVeryInteresting;
eol The operator must be at the end of the line. For example: 
    someVariable = aBigVariableNameToMakeThings + "this may work" +
                   lookVeryInteresting;

Block Policy

This property represents the policy for checking block statements. The following table describes the valid options:

Option Definition
ignore Ignore empty blocks.
text Require that there is some text in the block. For example: 
    catch (Exception ex) {
        // This is a bad coding practice
    }
stmt Require that there is a statement in the block. For example: 
    finally {
        lock.release();
    }

left curly brace policy

This property represents the policy for checking the placement of a left curly brace ('{'). The following table describes the valid options:

Option Definition
ignore Ignore the placement of the brace.
eol The brace must always be on the end of the line. For example: 
    if (condition) {
        ...
nl The brace must always be on a new line. For example: 
    if (condition)
    {
        ...
nlow If the brace will fit on the first line of the statement, taking into account maximum line length, then apply eol rule. Otherwise apply the nl rule. nlow is a mnemonic for "new line on wrap". For the example above Checkstyle will enforce: 
    if (condition) {
        ...
But for a statement spanning multiple lines, Checkstyle will enforce: 
    if (condition1 && condition2 &&
        condition3 && condition4)
    {
        ...

right curly brace policy

This property represents the policy for checking the placement of a right curly brace ('}'). The following table describes the valid options:

Option Definition
ignore Ignore the placement of the brace.
same The brace must be on the same line as the next statement. For example: 
    try {
        ...
    } finally {
alone The brace must be alone on the line. For example: 
    try {
        ...
    }
    finally {

Scope

This property represents a Java scope. The valid options are:

Copyright © 2002 Oliver Burn. All rights Reserved.