public class

Assert

extends Object
java.lang.Object
   ↳ org.junit.Assert

Class Overview

A set of assertion methods useful for writing tests. Only failed assertions are recorded. These methods can be used directly: Assert.assertEquals(...), however, they read better if they are referenced through static import:

 import static org.junit.Assert.*;
    ...
    assertEquals(...);
 

See Also
  • AssertionError

Summary

Protected Constructors
Assert()
Protect constructor since it is a static only class
Public Methods
static void assertArrayEquals(String message, char[] expecteds, char[] actuals)
Asserts that two char arrays are equal.
static void assertArrayEquals(Object[] expecteds, Object[] actuals)
Asserts that two object 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(byte[] expecteds, byte[] actuals)
Asserts that two byte arrays are equal.
static void assertArrayEquals(String message, short[] expecteds, short[] actuals)
Asserts that two short arrays are equal.
static void assertArrayEquals(String message, byte[] expecteds, byte[] actuals)
Asserts that two byte arrays are equal.
static void assertArrayEquals(String message, int[] expecteds, int[] actuals)
Asserts that two int 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, Object[] expecteds, Object[] actuals)
Asserts that two object arrays are equal.
static void assertArrayEquals(String message, double[] expecteds, double[] actuals, double delta)
Asserts that two double 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(short[] expecteds, short[] actuals)
Asserts that two short arrays are equal.
static void assertArrayEquals(float[] expecteds, float[] actuals, float delta)
Asserts that two float arrays are equal.
static void assertArrayEquals(String message, long[] expecteds, long[] actuals)
Asserts that two long arrays are equal.
static void assertEquals(String message, double expected, double actual, double delta)
Asserts that two doubles or 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(Object expected, Object actual)
Asserts that two objects are equal.
static void assertEquals(String message, double expected, double actual)
This method is deprecated. Use assertEquals(String message, double expected, double actual, double epsilon) instead
static void assertEquals(String message, Object[] expecteds, Object[] actuals)
This method is deprecated. use assertArrayEquals
static void assertEquals(Object[] expecteds, Object[] actuals)
This method is deprecated. use assertArrayEquals
static void assertEquals(double expected, double actual)
This method is deprecated. Use assertEquals(double expected, double actual, double epsilon) instead
static void assertEquals(double expected, double actual, double delta)
Asserts that two doubles or floats are equal to within a positive delta.
static void assertEquals(String message, Object expected, Object actual)
Asserts that two objects are equal.
static void assertEquals(long expected, long actual)
Asserts that two longs are equal.
static void assertFalse(String message, boolean condition)
Asserts that a condition is false.
static void assertFalse(boolean condition)
Asserts that a condition is false.
static void assertNotNull(String message, Object object)
Asserts that an object isn't null.
static void assertNotNull(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 <T> void assertThat(String reason, T actual, Matcher<T> matcher)
Asserts that actual satisfies the condition specified by matcher.
static <T> void assertThat(T actual, Matcher<T> matcher)
Asserts that actual satisfies the condition specified by matcher.
static void assertTrue(String message, boolean condition)
Asserts that a condition is true.
static void assertTrue(boolean condition)
Asserts that a condition is true.
static void fail(String message)
Fails a test with the given message.
static void fail()
Fails a test with no message.
[Expand]
Inherited Methods
From class java.lang.Object

Protected Constructors

protected Assert ()

Protect constructor since it is a static only class

Public Methods

public static void assertArrayEquals (String message, char[] expecteds, char[] actuals)

Asserts that two char arrays are equal. If they are not, an AssertionError is thrown with the given message.

Parameters
message the identifying message for the AssertionError (null okay)
expecteds char array with expected values.
actuals char array with actual values

public static void assertArrayEquals (Object[] expecteds, Object[] actuals)

Asserts that two object arrays are equal. If they are not, an AssertionError is thrown. If expected and actual are null, they are considered equal.

Parameters
expecteds Object array or array of arrays (multi-dimensional array) with expected values
actuals Object array or array of arrays (multi-dimensional array) with actual values

public static void assertArrayEquals (char[] expecteds, char[] actuals)

Asserts that two char arrays are equal. If they are not, an AssertionError is thrown.

Parameters
expecteds char array with expected values.
actuals char array with actual values

public static void assertArrayEquals (double[] expecteds, double[] actuals, double delta)

Asserts that two double arrays are equal. If they are not, an AssertionError is thrown.

Parameters
expecteds double array with expected values.
actuals double array with actual values

public static void assertArrayEquals (byte[] expecteds, byte[] actuals)

Asserts that two byte arrays are equal. If they are not, an AssertionError is thrown.

Parameters
expecteds byte array with expected values.
actuals byte array with actual values

public static void assertArrayEquals (String message, short[] expecteds, short[] actuals)

Asserts that two short arrays are equal. If they are not, an AssertionError is thrown with the given message.

Parameters
message the identifying message for the AssertionError (null okay)
expecteds short array with expected values.
actuals short array with actual values

public static void assertArrayEquals (String message, byte[] expecteds, byte[] actuals)

Asserts that two byte arrays are equal. If they are not, an AssertionError is thrown with the given message.

Parameters
message the identifying message for the AssertionError (null okay)
expecteds byte array with expected values.
actuals byte array with actual values

public static void assertArrayEquals (String message, int[] expecteds, int[] actuals)

Asserts that two int arrays are equal. If they are not, an AssertionError is thrown with the given message.

Parameters
message the identifying message for the AssertionError (null okay)
expecteds int array with expected values.
actuals int array with actual values

public static void assertArrayEquals (String message, float[] expecteds, float[] actuals, float delta)

Asserts that two float arrays are equal. If they are not, an AssertionError is thrown with the given message.

Parameters
message the identifying message for the AssertionError (null okay)
expecteds float array with expected values.
actuals float array with actual values

public static void assertArrayEquals (String message, Object[] expecteds, Object[] actuals)

Asserts that two object arrays are equal. If they are not, an AssertionError is thrown with the given message. If expecteds and actuals are null, they are considered equal.

Parameters
message the identifying message for the AssertionError (null okay)
expecteds Object array or array of arrays (multi-dimensional array) with expected values.
actuals Object array or array of arrays (multi-dimensional array) with actual values

public static void assertArrayEquals (String message, double[] expecteds, double[] actuals, double delta)

Asserts that two double arrays are equal. If they are not, an AssertionError is thrown with the given message.

Parameters
message the identifying message for the AssertionError (null okay)
expecteds double array with expected values.
actuals double array with actual values

public static void assertArrayEquals (int[] expecteds, int[] actuals)

Asserts that two int arrays are equal. If they are not, an AssertionError is thrown.

Parameters
expecteds int array with expected values.
actuals int array with actual values

public static void assertArrayEquals (long[] expecteds, long[] actuals)

Asserts that two long arrays are equal. If they are not, an AssertionError is thrown.

Parameters
expecteds long array with expected values.
actuals long array with actual values

public static void assertArrayEquals (short[] expecteds, short[] actuals)

Asserts that two short arrays are equal. If they are not, an AssertionError is thrown.

Parameters
expecteds short array with expected values.
actuals short array with actual values

public static void assertArrayEquals (float[] expecteds, float[] actuals, float delta)

Asserts that two float arrays are equal. If they are not, an AssertionError is thrown.

Parameters
expecteds float array with expected values.
actuals float array with actual values

public static void assertArrayEquals (String message, long[] expecteds, long[] actuals)

Asserts that two long arrays are equal. If they are not, an AssertionError is thrown with the given message.

Parameters
message the identifying message for the AssertionError (null okay)
expecteds long array with expected values.
actuals long array with actual values

public static void assertEquals (String message, double expected, double actual, double delta)

Asserts that two doubles or floats are equal to within a positive delta. If they are not, an AssertionError is thrown with the given message. If the expected value is infinity then the delta value is ignored. NaNs are considered equal: assertEquals(Double.NaN, Double.NaN, *) passes

Parameters
message the identifying message for the AssertionError (null okay)
expected expected value
actual the value to check against expected
delta the maximum delta between expected and actual for which both numbers are still considered equal.

public static void assertEquals (String message, long expected, long actual)

Asserts that two longs are equal. If they are not, an AssertionError is thrown with the given message.

Parameters
message the identifying message for the AssertionError (null okay)
expected long expected value.
actual long actual value

public static void assertEquals (Object expected, Object actual)

Asserts that two objects are equal. If they are not, an AssertionError without a message is thrown. If expected and actual are null, they are considered equal.

Parameters
expected expected value
actual the value to check against expected

public static void assertEquals (String message, double expected, double actual)

This method is deprecated.
Use assertEquals(String message, double expected, double actual, double epsilon) instead

public static void assertEquals (String message, Object[] expecteds, Object[] actuals)

This method is deprecated.
use assertArrayEquals

Asserts that two object arrays are equal. If they are not, an AssertionError is thrown with the given message. If expecteds and actuals are null, they are considered equal.

Parameters
message the identifying message for the AssertionError (null okay)
expecteds Object array or array of arrays (multi-dimensional array) with expected values.
actuals Object array or array of arrays (multi-dimensional array) with actual values

public static void assertEquals (Object[] expecteds, Object[] actuals)

This method is deprecated.
use assertArrayEquals

Asserts that two object arrays are equal. If they are not, an AssertionError is thrown. If expected and actual are null, they are considered equal.

Parameters
expecteds Object array or array of arrays (multi-dimensional array) with expected values
actuals Object array or array of arrays (multi-dimensional array) with actual values

public static void assertEquals (double expected, double actual)

This method is deprecated.
Use assertEquals(double expected, double actual, double epsilon) instead

public static void assertEquals (double expected, double actual, double delta)

Asserts that two doubles or floats are equal to within a positive delta. If they are not, an AssertionError is thrown. If the expected value is infinity then the delta value is ignored.NaNs are considered equal: assertEquals(Double.NaN, Double.NaN, *) passes

Parameters
expected expected value
actual the value to check against expected
delta the maximum delta between expected and actual for which both numbers are still considered equal.

public static void assertEquals (String message, Object expected, Object actual)

Asserts that two objects are equal. If they are not, an AssertionError is thrown with the given message. If expected and actual are null, they are considered equal.

Parameters
message the identifying message for the AssertionError (null okay)
expected expected value
actual actual value

public static void assertEquals (long expected, long actual)

Asserts that two longs are equal. If they are not, an AssertionError is thrown.

Parameters
expected expected long value.
actual actual long value

public static void assertFalse (String message, boolean condition)

Asserts that a condition is false. If it isn't it throws an AssertionError with the given message.

Parameters
message the identifying message for the AssertionError (null okay)
condition condition to be checked

public static void assertFalse (boolean condition)

Asserts that a condition is false. If it isn't it throws an AssertionError without a message.

Parameters
condition condition to be checked

public static void assertNotNull (String message, Object object)

Asserts that an object isn't null. If it is an AssertionError is thrown with the given message.

Parameters
message the identifying message for the AssertionError (null okay)
object Object to check or null

public static void assertNotNull (Object object)

Asserts that an object isn't null. If it is an AssertionError is thrown.

Parameters
object Object to check or null

public static void assertNotSame (Object unexpected, Object actual)

Asserts that two objects do not refer to the same object. If they do refer to the same object, an AssertionError without a message is thrown.

Parameters
unexpected the object you don't expect
actual the object to compare to unexpected

public static void assertNotSame (String message, Object unexpected, Object actual)

Asserts that two objects do not refer to the same object. If they do refer to the same object, an AssertionError is thrown with the given message.

Parameters
message the identifying message for the AssertionError (null okay)
unexpected the object you don't expect
actual the object to compare to unexpected

public static void assertNull (Object object)

Asserts that an object is null. If it isn't an AssertionError is thrown.

Parameters
object Object to check or null

public static void assertNull (String message, Object object)

Asserts that an object is null. If it is not, an AssertionError is thrown with the given message.

Parameters
message the identifying message for the AssertionError (null okay)
object Object to check or null

public static void assertSame (Object expected, Object actual)

Asserts that two objects refer to the same object. If they are not the same, an AssertionError without a message is thrown.

Parameters
expected the expected object
actual the object to compare to expected

public static void assertSame (String message, Object expected, Object actual)

Asserts that two objects refer to the same object. If they are not, an AssertionError is thrown with the given message.

Parameters
message the identifying message for the AssertionError (null okay)
expected the expected object
actual the object to compare to expected

public static void assertThat (String reason, T actual, Matcher<T> matcher)

Asserts that actual satisfies the condition specified by matcher. If not, an AssertionError is thrown with the reason and information about the matcher and failing value. Example:

 :
   assertThat("Help! Integers don't work", 0, is(1)); // fails:
     // failure message:
     // Help! Integers don't work
     // expected: is <1> 
     // got value: <0>
   assertThat("Zero is one", 0, is(not(1))) // passes
 

Parameters
reason additional information about the error
actual the computed value being compared
matcher an expression, built of Matchers, specifying allowed values
See Also

public static void assertThat (T actual, Matcher<T> matcher)

Asserts that actual satisfies the condition specified by matcher. If not, an AssertionError is thrown with information about the matcher and failing value. Example:

   assertThat(0, is(1)); // fails:
     // failure message:
     // expected: is <1> 
     // got value: <0>
   assertThat(0, is(not(1))) // passes
 

Parameters
actual the computed value being compared
matcher an expression, built of Matchers, specifying allowed values
See Also

public static void assertTrue (String message, boolean condition)

Asserts that a condition is true. If it isn't it throws an AssertionError with the given message.

Parameters
message the identifying message for the AssertionError (null okay)
condition condition to be checked

public static void assertTrue (boolean condition)

Asserts that a condition is true. If it isn't it throws an AssertionError without a message.

Parameters
condition condition to be checked

public static void fail (String message)

Fails a test with the given message.

Parameters
message the identifying message for the AssertionError (null okay)
See Also
  • AssertionError

public static void fail ()

Fails a test with no message.