1package org.hamcrest.core; 2 3import org.hamcrest.BaseMatcher; 4import org.hamcrest.Description; 5import org.hamcrest.Matcher; 6 7import static org.hamcrest.core.IsEqual.equalTo; 8 9 10/** 11 * Calculates the logical negation of a matcher. 12 */ 13public class IsNot<T> extends BaseMatcher<T> { 14 private final Matcher<T> matcher; 15 16 public IsNot(Matcher<T> matcher) { 17 this.matcher = matcher; 18 } 19 20 @Override 21 public boolean matches(Object arg) { 22 return !matcher.matches(arg); 23 } 24 25 @Override 26 public void describeTo(Description description) { 27 description.appendText("not ").appendDescriptionOf(matcher); 28 } 29 30 31 /** 32 * Creates a matcher that wraps an existing matcher, but inverts the logic by which 33 * it will match. 34 * For example: 35 * <pre>assertThat(cheese, is(not(equalTo(smelly))))</pre> 36 * 37 * @param matcher 38 * the matcher whose sense should be inverted 39 */ 40 public static <T> Matcher<T> not(Matcher<T> matcher) { 41 return new IsNot<T>(matcher); 42 } 43 44 /** 45 * A shortcut to the frequently used <code>not(equalTo(x))</code>. 46 * For example: 47 * <pre>assertThat(cheese, is(not(smelly)))</pre> 48 * instead of: 49 * <pre>assertThat(cheese, is(not(equalTo(smelly))))</pre> 50 * 51 * @param value 52 * the value that any examined object should <b>not</b> equal 53 */ 54 public static <T> Matcher<T> not(T value) { 55 return not(equalTo(value)); 56 } 57} 58