断言是编写测试用例的核心实现方式，即期望值是多少，测试的结果是多少，以此来判断测试是否通过。

  1. 断言核心方法

  1. 示例
package test;
 
import static org.hamcrest.CoreMatchers.*;
import static org.junit.Assert.*;
 
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();
	    org.junit.Assert.assertArrayEquals("failure - byte arrays not same", expected, actual);
	  }
 
	  @Test
	  public void testAssertEquals() {
	    org.junit.Assert.assertEquals("failure - strings not same", 5l, 5l);
	  }
 
	  @Test
	  public void testAssertFalse() {
	    org.junit.Assert.assertFalse("failure - should be false", false);
	  }
 
	  @Test
	  public void testAssertNotNull() {
	    org.junit.Assert.assertNotNull("should not be null", new Object());
	  }
 
	  @Test
	  public void testAssertNotSame() {
	    org.junit.Assert.assertNotSame("should not be same Object", new Object(), new Object());
	  }
 
	  @Test
	  public void testAssertNull() {
	    org.junit.Assert.assertNull("should be null", null);
	  }
 
	  @Test
	  public void testAssertSame() {
	    Integer aNumber = Integer.valueOf(768);
	    org.junit.Assert.assertSame("should be 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.<Integer> either(equalTo(3)).or(equalTo(4))));
	    assertThat(new Object(), not(sameInstance(new Object())));
	  }
}