public static boolean isSymlink(File file) throws IOException {
if (file == null) {
throw new NullPointerException("File must not be null");
}
if (FilenameUtils.isSystemWindows()) {
return false;
}
File fileInCanonicalDir = null;
if (file.getParent() == null) {
fileInCanonicalDir = file;
} else {
File canonicalDir = file.getParentFile().getCanonicalFile();
fileInCanonicalDir = new File(canonicalDir, file.getName());
}
if (fileInCanonicalDir.getCanonicalFile().equals(fileInCanonicalDir.getAbsoluteFile())) {
return false;
}
return true;
}
/**
* Enumeration of IO case sensitivity.
*
* <p>Different filing systems have different rules for case-sensitivity. Windows is
* case-insensitive, Unix is case-sensitive.
*
* <p>This class captures that difference, providing an enumeration to control how filename
* comparisons should be performed. It also provides methods that use the enumeration to perform
* comparisons.
*
* <p>Wherever possible, you should use the <code>check</code> methods in this class to compare
* filenames.
*
* @author Stephen Colebourne
* @version $Id$
* @since Commons IO 1.3
*/
public final class IOCase implements Serializable {
/** The constant for case sensitive regardless of operating system. */
public static final IOCase SENSITIVE = new IOCase("Sensitive", true);
/** The constant for case insensitive regardless of operating system. */
public static final IOCase INSENSITIVE = new IOCase("Insensitive", false);
/**
* The constant for case sensitivity determined by the current operating system. Windows is
* case-insensitive when comparing filenames, Unix is case-sensitive.
*
* <p>If you derialize this constant of Windows, and deserialize on Unix, or vice versa, then the
* value of the case-sensitivity flag will change.
*/
public static final IOCase SYSTEM = new IOCase("System", !FilenameUtils.isSystemWindows());
/** Serialization version. */
private static final long serialVersionUID = -6343169151696340687L;
/** The enumeration name. */
private final String name;
/** The sensitivity flag. */
private final transient boolean sensitive;
// -----------------------------------------------------------------------
/**
* Factory method to create an IOCase from a name.
*
* @param name the name to find
* @return the IOCase object
* @throws IllegalArgumentException if the name is invalid
*/
public static IOCase forName(String name) {
if (IOCase.SENSITIVE.name.equals(name)) {
return IOCase.SENSITIVE;
}
if (IOCase.INSENSITIVE.name.equals(name)) {
return IOCase.INSENSITIVE;
}
if (IOCase.SYSTEM.name.equals(name)) {
return IOCase.SYSTEM;
}
throw new IllegalArgumentException("Invalid IOCase name: " + name);
}
// -----------------------------------------------------------------------
/**
* Private constructor.
*
* @param name the name
* @param sensitive the sensitivity
*/
private IOCase(String name, boolean sensitive) {
this.name = name;
this.sensitive = sensitive;
}
/**
* Replaces the enumeration from the stream with a real one. This ensures that the correct flag is
* set for SYSTEM.
*
* @return the resolved object
*/
private Object readResolve() {
return forName(name);
}
// -----------------------------------------------------------------------
/**
* Gets the name of the constant.
*
* @return the name of the constant
*/
public String getName() {
return name;
}
/**
* Does the object represent case sensitive comparison.
*
* @return true if case sensitive
*/
public boolean isCaseSensitive() {
return sensitive;
}
// -----------------------------------------------------------------------
/**
* Compares two strings using the case-sensitivity rule.
*
* <p>This method mimics {@link String#compareTo} but takes case-sensitivity into account.
*
* @param str1 the first string to compare, not null
* @param str2 the second string to compare, not null
* @return true if equal using the case rules
* @throws NullPointerException if either string is null
*/
public int checkCompareTo(String str1, String str2) {
if (str1 == null || str2 == null) {
throw new NullPointerException("The strings must not be null");
}
return sensitive ? str1.compareTo(str2) : str1.compareToIgnoreCase(str2);
}
/**
* Compares two strings using the case-sensitivity rule.
*
* <p>This method mimics {@link String#equals} but takes case-sensitivity into account.
*
* @param str1 the first string to compare, not null
* @param str2 the second string to compare, not null
* @return true if equal using the case rules
* @throws NullPointerException if either string is null
*/
public boolean checkEquals(String str1, String str2) {
if (str1 == null || str2 == null) {
throw new NullPointerException("The strings must not be null");
}
return sensitive ? str1.equals(str2) : str1.equalsIgnoreCase(str2);
}
/**
* Checks if one string starts with another using the case-sensitivity rule.
*
* <p>This method mimics {@link String#startsWith(String)} but takes case-sensitivity into
* account.
*
* @param str the string to check, not null
* @param start the start to compare against, not null
* @return true if equal using the case rules
* @throws NullPointerException if either string is null
*/
public boolean checkStartsWith(String str, String start) {
return str.regionMatches(!sensitive, 0, start, 0, start.length());
}
/**
* Checks if one string ends with another using the case-sensitivity rule.
*
* <p>This method mimics {@link String#endsWith} but takes case-sensitivity into account.
*
* @param str the string to check, not null
* @param end the end to compare against, not null
* @return true if equal using the case rules
* @throws NullPointerException if either string is null
*/
public boolean checkEndsWith(String str, String end) {
int endLen = end.length();
return str.regionMatches(!sensitive, str.length() - endLen, end, 0, endLen);
}
/**
* Checks if one string contains another at a specific index using the case-sensitivity rule.
*
* <p>This method mimics parts of {@link String#regionMatches(boolean, int, String, int, int)} but
* takes case-sensitivity into account.
*
* @param str the string to check, not null
* @param strStartIndex the index to start at in str
* @param search the start to search for, not null
* @return true if equal using the case rules
* @throws NullPointerException if either string is null
*/
public boolean checkRegionMatches(String str, int strStartIndex, String search) {
return str.regionMatches(!sensitive, strStartIndex, search, 0, search.length());
}
/**
* Converts the case of the input String to a standard format. Subsequent operations can then use
* standard String methods.
*
* @param str the string to convert, null returns null
* @return the lower-case version if case-insensitive
*/
String convertCase(String str) {
if (str == null) {
return null;
}
return sensitive ? str : str.toLowerCase();
}
// -----------------------------------------------------------------------
/**
* Gets a string describing the sensitivity.
*
* @return a string describing the sensitivity
*/
public String toString() {
return name;
}
}
