com.puppycrawl.tools.checkstyle.utils

Class CommonUtils

java.lang.Object

com.puppycrawl.tools.checkstyle.utils.CommonUtils

public final class CommonUtils
extends Object

Contains utility methods.

Author:

Aleksey Nesterenko

Method Summary

Modifier and Type	Method and Description
static String	baseClassName(String type)
static void	close(Closeable closeable) Closes a stream re-throwing IOException as IllegalStateException.
static Pattern	createPattern(String pattern) Helper method to create a regular expression.
static boolean	endsWithChar(String value, char suffix) Tests if this string ends with the specified suffix.
static Constructor<?>	getConstructor(Class<?> targetClass, Class<?>... parameterTypes) Gets constructor of targetClass.
static URI	getUriByFilename(String filename) Resolve the specified filename to a URI.
static boolean	hasWhitespaceBefore(int index, String line) Returns whether the specified string contains only whitespace up to the specified index.
static <T> T	invokeConstructor(Constructor<T> constructor, Object... parameters)
static boolean	isPatternValid(String pattern) Validates whether passed string is a valid pattern or not.
static int	lengthExpandedTabs(String inputString, int toIdx, int tabWidth) Returns the length of a String prefix with tabs expanded.
static int	lengthMinusTrailingWhitespace(String line) Returns the length of a string ignoring all trailing whitespace.
static boolean	matchesFileExtension(File file, String... fileExtensions) Returns whether the file extension matches what we are meant to process.
static String	relativizeAndNormalizePath(String baseDirectory, String path) Constructs a normalized relative path between base directory and a given path.
static boolean	startsWithChar(String value, char prefix) Tests if this string starts with the specified prefix.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

matchesFileExtension

public static boolean matchesFileExtension(File file,
                                           String... fileExtensions)

Returns whether the file extension matches what we are meant to process.

Parameters:

file - the file to be checked.

fileExtensions - files extensions, empty property in config makes it matches to all.

Returns:

whether there is a match.

hasWhitespaceBefore

public static boolean hasWhitespaceBefore(int index,
                                          String line)

Returns whether the specified string contains only whitespace up to the specified index.

Parameters:

index - index to check up to

line - the line to check

Returns:

whether there is only whitespace

lengthMinusTrailingWhitespace

public static int lengthMinusTrailingWhitespace(String line)

Returns the length of a string ignoring all trailing whitespace. It is a pity that there is not a trim() like method that only removed the trailing whitespace.

Parameters:

line - the string to process

Returns:

the length of the string ignoring all trailing whitespace

lengthExpandedTabs

public static int lengthExpandedTabs(String inputString,
                                     int toIdx,
                                     int tabWidth)

Returns the length of a String prefix with tabs expanded. Each tab is counted as the number of characters is takes to jump to the next tab stop.

Parameters:

inputString - the input String

toIdx - index in string (exclusive) where the calculation stops

tabWidth - the distance between tab stop position.

Returns:

the length of string.substring(0, toIdx) with tabs expanded.

isPatternValid

public static boolean isPatternValid(String pattern)

Validates whether passed string is a valid pattern or not.

Parameters:

pattern - string to validate

Returns:

true if the pattern is valid false otherwise

createPattern

public static Pattern createPattern(String pattern)

Helper method to create a regular expression.

Parameters:

pattern - the pattern to match

Returns:

a created regexp object

Throws:

org.apache.commons.beanutils.ConversionException - if unable to create Pattern object.

baseClassName

public static String baseClassName(String type)

Parameters:

type - the fully qualified name. Cannot be null

Returns:

the base class name from a fully qualified name

relativizeAndNormalizePath

public static String relativizeAndNormalizePath(String baseDirectory,
                                                String path)

Constructs a normalized relative path between base directory and a given path.

Parameters:

baseDirectory - the base path to which given path is relativized

path - the path to relativize against base directory

Returns:

the relative normalized path between base directory and path or path if base directory is null.

startsWithChar

public static boolean startsWithChar(String value,
                                     char prefix)

Tests if this string starts with the specified prefix.

It is faster version of String.startsWith(String) optimized for one-character prefixes at the expense of some readability. Suggested by SimplifyStartsWith PMD rule: http://pmd.sourceforge.net/pmd-5.3.1/pmd-java/rules/java/optimizations.html#SimplifyStartsWith

Parameters:

value - the String to check

prefix - the prefix to find

Returns:

true if the char is a prefix of the given String; false otherwise.

endsWithChar

public static boolean endsWithChar(String value,
                                   char suffix)

Tests if this string ends with the specified suffix.

It is faster version of String.endsWith(String) optimized for one-character suffixes at the expense of some readability. Suggested by SimplifyStartsWith PMD rule: http://pmd.sourceforge.net/pmd-5.3.1/pmd-java/rules/java/optimizations.html#SimplifyStartsWith

Parameters:

value - the String to check

suffix - the suffix to find

Returns:

true if the char is a suffix of the given String; false otherwise.

getConstructor

public static Constructor<?> getConstructor(Class<?> targetClass,
                                            Class<?>... parameterTypes)

Gets constructor of targetClass.

Parameters:

targetClass - from which constructor is returned

parameterTypes - of constructor

Returns:

constructor of targetClass or IllegalStateException if any exception occurs

See Also:

Class.getConstructor(Class[])

invokeConstructor

public static <T> T invokeConstructor(Constructor<T> constructor,
                                      Object... parameters)

Type Parameters:

T - type of constructor

Parameters:

constructor - to invoke

parameters - to pass to constructor

Returns:

new instance of class or IllegalStateException if any exception occurs

See Also:

Constructor.newInstance(Object...)

close

public static void close(Closeable closeable)

Closes a stream re-throwing IOException as IllegalStateException.

Parameters:

closeable - Closeable object

getUriByFilename

public static URI getUriByFilename(String filename)
                            throws CheckstyleException

Resolve the specified filename to a URI.

Parameters:

filename - name os the file

Returns:

resolved header file URI

Throws:

CheckstyleException - on failure