Assertions

JUnit은 "import static org.junit.Assert.*"를 통해 가져올 수 있는 여러 가지 재부팅 단언 방법을 제공합니다.방법의 매개 변수 순서는 일반적으로 ([실패할 때 인쇄된 문자열 메시지], 기대치, 실제값)이다.
특히 언급해야 할 단언은 assertThat인데, 그 매개 변수는 ([실패할 때 출력된 문자열 메시지], 실제 값,Matcher 대상) 이고, 매개 변수의 순서는 다른 단언 방법과 정반대이다.또한 Matcher 객체를 생성하려면 org가 필요합니다.hamcrest.CoreMatchers.*"안에 있는 방법이기 때문에 assertThat을 사용할 때hamcrest-core.jar와hamcrest-library.jar(다운로드 주소:http://search.maven.org/#search|ga|1|g%3Aorg.hamcrest).AssertThat에 대한 자세한 내용은 "Matchers and assertthat"을 참조하십시오.
Hamcrest가 뭘까요?공식 홈페이지에는 amcrest is a library of matchers, which can be combined in to create flexible expressions of intent in tests가 있습니다.내 이해에 따르면 Hamcrest는 Library이다. 이것은 매칭 부호인 Matcher를 제공했다. 이런 매칭 부호는 읽을 수 있고 유연하기 때문에 JUnit4는Hamcrest 프레임워크를 도입했다.
Hamcrest 홈페이지:http://hamcrest.org/.
Hamcrest 홈 페이지:http://code.google.com/p/hamcrest/wiki/Tutorial
Hamcrest 전체 패키지의 GitHub 다운로드 주소:https://github.com/hamcrest/JavaHamcrest
Method Summary static void assertArrayEquals(boolean[] expecteds, boolean[] actuals)           Asserts that two boolean arrays are equal. static void assertArrayEquals(byte[] expecteds, byte[] actuals)           Asserts that two byte arrays are equal. static void assertArrayEquals(char[] expecteds, char[] actuals)           Asserts that two char arrays are equal. static void assertArrayEquals(double[] expecteds, double[] actuals, double delta)           Asserts that two double arrays are equal. static void assertArrayEquals(float[] expecteds, float[] actuals, float delta)           Asserts that two float arrays are equal. static void assertArrayEquals(int[] expecteds, int[] actuals)           Asserts that two int arrays are equal. static void assertArrayEquals(long[] expecteds, long[] actuals)           Asserts that two long arrays are equal. static void assertArrayEquals(Object[] expecteds,Object[] actuals)           Asserts that two object arrays are equal. static void assertArrayEquals(short[] expecteds, short[] actuals)           Asserts that two short arrays are equal. static void assertArrayEquals(String message, boolean[] expecteds, boolean[] actuals)           Asserts that two boolean arrays are equal. static void assertArrayEquals(String message, byte[] expecteds, byte[] actuals)           Asserts that two byte arrays are equal. static void assertArrayEquals(String message, char[] expecteds, char[] actuals)           Asserts that two char arrays are equal. static void assertArrayEquals(String message, double[] expecteds, double[] actuals, double delta)           Asserts that two double arrays are equal. static void assertArrayEquals(String message, float[] expecteds, float[] actuals, float delta)           Asserts that two float arrays are equal. static void assertArrayEquals(String message, int[] expecteds, int[] actuals)           Asserts that two int arrays are equal. static void assertArrayEquals(String message, long[] expecteds, long[] actuals)           Asserts that two long arrays are equal. static void assertArrayEquals(String message,Object[] expecteds,Object[] actuals)           Asserts that two object arrays are equal. static void assertArrayEquals(String message, short[] expecteds, short[] actuals)           Asserts that two short arrays are equal. static void assertEquals(double expected, double actual)           Deprecated. Use assertEquals(double expected, double actual, double delta) instead static void assertEquals(double expected, double actual, double delta)           Asserts that two doubles are equal to within a positive delta. static void assertEquals(float expected, float actual, float delta)           Asserts that two floats are equal to within a positive delta. static void assertEquals(long expected, long actual)           Asserts that two longs are equal. static void assertEquals(Object[] expecteds,Object[] actuals)           Deprecated. use assertArrayEquals static void assertEquals(Object expected,Object actual)           Asserts that two objects are equal. static void assertEquals(String message, double expected, double actual)           Deprecated. Use assertEquals(String message, double expected, double actual, double delta) instead static void assertEquals(String message, double expected, double actual, double delta)           Asserts that two doubles are equal to within a positive delta. static void assertEquals(String message, float expected, float actual, float delta)           Asserts that two floats are equal to within a positive delta. static void assertEquals(String message, long expected, long actual)           Asserts that two longs are equal. static void assertEquals(String message,Object[] expecteds,Object[] actuals)           Deprecated. use assertArrayEquals static void assertEquals(String message,Object expected,Object actual)           Asserts that two objects are equal. static void assertFalse(boolean condition)           Asserts that a condition is false. static void assertFalse(String message, boolean condition)           Asserts that a condition is false. static void assertNotEquals(double unexpected, double actual, double delta)           Asserts that two doubles are not equal to within a positive delta. static void assertNotEquals(float unexpected, float actual, float delta)           Asserts that two floats are not equal to within a positive delta. static void assertNotEquals(long unexpected, long actual)           Asserts that two longs are not equals. static void assertNotEquals(Object unexpected,Object actual)           Asserts that two objects are not equals. static void assertNotEquals(String message, double unexpected, double actual, double delta)           Asserts that two doubles are not equal to within a positive delta. static void assertNotEquals(String message, float unexpected, float actual, float delta)           Asserts that two floats are not equal to within a positive delta. static void assertNotEquals(String message, long unexpected, long actual)           Asserts that two longs are not equals. static void assertNotEquals(String message,Object unexpected,Object actual)           Asserts that two objects are not equals. static void assertNotNull(Object object)           Asserts that an object isn't null. static void assertNotNull(String message,Object object)           Asserts that an object isn't null. static void assertNotSame(Object unexpected,Object actual)           Asserts that two objects do not refer to the same object. static void assertNotSame(String message,Object unexpected,Object actual)           Asserts that two objects do not refer to the same object. static void assertNull(Object object)           Asserts that an object is null. static void assertNull(String message,Object object)           Asserts that an object is null. static void assertSame(Object expected,Object actual)           Asserts that two objects refer to the same object. static void assertSame(String message,Object expected,Object actual)           Asserts that two objects refer to the same object. static void assertThat(String reason, T actual, Matcher super T> matcher)           Asserts that actual satisfies the condition specified by matcher . static void assertThat(T actual,Matcher super T> matcher)           Asserts that actual satisfies the condition specified by matcher . static void assertTrue(boolean condition)           Asserts that a condition is true. static void assertTrue(String message, boolean condition)           Asserts that a condition is true. static void fail()           Fails a test with no message. static void fail(String message)
홈페이지의 단언은 다음과 같다.

import static org.junit.Assert.*;
import static org.hamcrest.CoreMatchers.*;

import java.util.Arrays;
import org.hamcrest.core.CombinableMatcher;
import org.junit.Test;


public class AssertTests {
	
	@Test
	public void testAssertArrayEquals(){
		byte[] expected="trial".getBytes();
		byte[] actual="trial".getBytes();
		assertArrayEquals("failure-byte arrays not same",expected, actual);
	}
	
	@Test
	public void testAssertEquals(){
		assertEquals("failure-strings are not equal","test","test");
	}
	
	@Test
	public void testAssertFalse(){
		assertFalse("failure-should be false",false);
	}
	
	@Test
	public void testAssertNotNull(){
		assertNotNull("should not be null",new Object());
	}
	
	@Test
	public void testAssertNotSame(){
		assertNotSame("should not be same object",new Object(),new String("hello"));
	}

	@Test
	public void testAssertNull(){
		assertNull("should be null",null);
	}
	
	@Test
	public void testAssertSame(){
		Integer aNumber=Integer.valueOf(78);
		assertSame("should be the same",aNumber,aNumber);
	}
	
	  // JUnit Matchers assertThat
	  @Test
	  public void testAssertThatBothContainsString() {
	    org.junit.Assert.assertThat("albumen", both(containsString("a")).and(containsString("b")));
	  }

	  @Test
	  public void testAssertThathasItemsContainsString() {
	    org.junit.Assert.assertThat(Arrays.asList("one", "two", "three"), hasItems("one", "three"));
	  }

	  @Test
	  public void testAssertThatEveryItemContainsString() {
	    org.junit.Assert.assertThat(Arrays.asList(new String[] { "fun", "ban", "net" }), everyItem(containsString("n")));
	  }

	  // Core Hamcrest Matchers with assertThat
	  @Test
	  public void testAssertThatHamcrestCoreMatchers() {
	    assertThat("good", allOf(equalTo("good"), startsWith("good")));
	    assertThat("good", not(allOf(equalTo("bad"), equalTo("good"))));
	    assertThat("good", anyOf(equalTo("bad"), equalTo("good")));
	    assertThat(7, not(CombinableMatcher. either(equalTo(3)).or(equalTo(4))));
	    assertThat(new Object(), not(sameInstance(new Object())));
	  }

	  @Test
	  public void testAssertTrue() {
	    assertTrue("failure - should be true", true);
	  }	
}