org.eclipse.e4.ui.internal.workbench

Class Util

java.lang.Object

org.eclipse.e4.ui.internal.workbench.Util

public final class Util
extends java.lang.Object

A static class providing utility methods to all of JFace.

Since:

3.1

Field Summary

Fields

Modifier and Type	Field and Description
static java.util.SortedSet<?>	EMPTY_SORTED_SET An unmodifiable, empty, sorted set.
static java.lang.String	ZERO_LENGTH_STRING A common zero-length string.

Method Summary

Modifier and Type	Method and Description
static void	assertInstance(java.lang.Object object, java.lang.Class<?> c) Verifies that the given object is an instance of the given class.
static int	compare(boolean left, boolean right) Compares two boolean values.
static int	compare(int left, int right) Compares two integer values.
static <T extends java.lang.Comparable<T>> int	compare(java.util.List<T> left, java.util.List<T> right) Compares two lists -- account for null.
static <T extends java.lang.Comparable<T>> int	compare(T[] left, T[] right) Compares two arrays of comparable objects -- accounting for null.
static <T extends java.lang.Comparable<T>> int	compare(T left, T right) Compares to comparable objects -- defending against null.
static boolean	endsWith(java.lang.Object[] left, java.lang.Object[] right, boolean equals) Tests whether the first array ends with the second array.
static boolean	equals(java.lang.Object[] leftArray, java.lang.Object[] rightArray) Tests whether two arrays of objects are equal to each other.
static boolean	equals(java.lang.Object left, java.lang.Object right) Checks whether the two objects are null -- allowing for null.
static int	hashCode(int i) Provides a hash code based on the given integer value.
static int	hashCode(java.lang.Object object) Provides a hash code for the object -- defending against null.
static int	hashCode(java.lang.Object[] objects) Computes the hash code for an array of objects, but with defense against null.
static java.lang.String	replaceAll(java.lang.String src, java.lang.String find, java.lang.String replacement) Foundation replacement for String#replaceAll(String, String), but without support for regular expressions.
static boolean	startsWith(java.lang.Object[] left, java.lang.Object[] right, boolean equals) Checks whether the second array is a subsequence of the first array, and that they share common starting elements.
static java.lang.String	toString(java.lang.Object[] array) Converts an array into a string representation that is suitable for debugging.
static java.lang.String	translateString(java.util.ResourceBundle resourceBundle, java.lang.String key, java.lang.String defaultString) Provides a translation of a particular key from the resource bundle.

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY_SORTED_SET

public static final java.util.SortedSet<?> EMPTY_SORTED_SET

An unmodifiable, empty, sorted set. This value is guaranteed to never change and never be null.

ZERO_LENGTH_STRING

public static final java.lang.String ZERO_LENGTH_STRING

A common zero-length string. It avoids needing write NON-NLS next to code fragments. It's also a bit clearer to read.

See Also:

Constant Field Values

Method Detail

assertInstance

public static final void assertInstance(java.lang.Object object,
                                        java.lang.Class<?> c)

Verifies that the given object is an instance of the given class.

Parameters:

object - The object to check; may be null.

c - The class which the object should be; must not be null.

compare

public static final int compare(boolean left,
                                boolean right)

Compares two boolean values. false is considered to be "less than" true.

Parameters:

left - The left value to compare

right - The right value to compare

Returns:

-1 if the left is false and the right is true. 1 if the opposite is true. If they are equal, then it returns 0.

compare

public static final int compare(int left,
                                int right)

Compares two integer values.

Parameters:

left - The left value to compare

right - The right value to compare

Returns:

left - right

compare

public static final <T extends java.lang.Comparable<T>> int compare(T left,
                                                                    T right)

Compares to comparable objects -- defending against null.

Parameters:

left - The left object to compare; may be null.

right - The right object to compare; may be null.

Returns:

The result of the comparison. null is considered to be the least possible value.

compare

public static final <T extends java.lang.Comparable<T>> int compare(T[] left,
                                                                    T[] right)

Compares two arrays of comparable objects -- accounting for null.

Parameters:

left - The left array to be compared; may be null.

right - The right array to be compared; may be null.

Returns:

The result of the comparison. null is considered to be the least possible value. A shorter array is considered less than a longer array.

compare

public static final <T extends java.lang.Comparable<T>> int compare(java.util.List<T> left,
                                                                    java.util.List<T> right)

Compares two lists -- account for null. The lists must contain comparable objects.

Parameters:

left - The left list to compare; may be null. This list must only contain instances of Comparable.

right - The right list to compare; may be null. This list must only contain instances of Comparable.

Returns:

The result of the comparison. null is considered to be the least possible value. A shorter list is considered less than a longer list.

endsWith

public static final boolean endsWith(java.lang.Object[] left,
                                     java.lang.Object[] right,
                                     boolean equals)

Tests whether the first array ends with the second array.

Parameters:

left - The array to check (larger); may be null.

right - The array that should be a subsequence (smaller); may be null.

equals - Whether the two array are allowed to be equal.

Returns:

true if the second array is a subsequence of the array list, and they share end elements.

equals

public static final boolean equals(java.lang.Object left,
                                   java.lang.Object right)

Checks whether the two objects are null -- allowing for null.

Parameters:

left - The left object to compare; may be null.

right - The right object to compare; may be null.

Returns:

true if the two objects are equivalent; false otherwise.

equals

public static final boolean equals(java.lang.Object[] leftArray,
                                   java.lang.Object[] rightArray)

Tests whether two arrays of objects are equal to each other. The arrays must not be null, but their elements may be null.

Parameters:

leftArray - The left array to compare; may be null, and may be empty and may contain null elements.

rightArray - The right array to compare; may be null, and may be empty and may contain null elements.

Returns:

true if the arrays are equal length and the elements at the same position are equal; false otherwise.

hashCode

public static final int hashCode(int i)

Provides a hash code based on the given integer value.

Parameters:

i - The integer value

Returns:

i

hashCode

public static final int hashCode(java.lang.Object object)

Provides a hash code for the object -- defending against null.

Parameters:

object - The object for which a hash code is required.

Returns:

object.hashCode or 0 if object if null.

hashCode

public static final int hashCode(java.lang.Object[] objects)

Computes the hash code for an array of objects, but with defense against null.

Parameters:

objects - The array of objects for which a hash code is needed; may be null.

Returns:

The hash code for objects; or 0 if objects is null.

startsWith

public static final boolean startsWith(java.lang.Object[] left,
                                       java.lang.Object[] right,
                                       boolean equals)

Checks whether the second array is a subsequence of the first array, and that they share common starting elements.

Parameters:

left - The first array to compare (large); may be null.

right - The second array to compare (small); may be null.

equals - Whether it is allowed for the two arrays to be equivalent.

Returns:

true if the first arrays starts with the second list; false otherwise.

toString

public static final java.lang.String toString(java.lang.Object[] array)

Converts an array into a string representation that is suitable for debugging.

Parameters:

array - The array to convert; may be null.

Returns:

The string representation of the array; never null.

translateString

public static final java.lang.String translateString(java.util.ResourceBundle resourceBundle,
                                                     java.lang.String key,
                                                     java.lang.String defaultString)

Provides a translation of a particular key from the resource bundle.

Parameters:

resourceBundle - The key to look up in the resource bundle; should not be null.

key - The key to look up in the resource bundle; should not be null.

defaultString - The value to return if the resource cannot be found; may be null.

Returns:

The value of the translated resource at key. If the key cannot be found, then it is simply the defaultString.

replaceAll

public static final java.lang.String replaceAll(java.lang.String src,
                                                java.lang.String find,
                                                java.lang.String replacement)

Foundation replacement for String#replaceAll(String, String), but without support for regular expressions.

Parameters:

src - the original string

find - the string to find

replacement - the replacement string

Returns:

the new string, with all occurrences of find replaced by replacement (not using regular expressions)

Since:

3.4