package junit.framework;

/**

 * Thrown when an assert equals for Strings failed.

 * 

 * Inspired by a patch from Alex Chaffee mailto:alex@purpletech.com

 */

public class ComparisonFailure extends AssertionFailedError {

	private static final int MAX_CONTEXT_LENGTH= 20;

	private static final long serialVersionUID= 1L;

	private String fExpected;

	private String fActual;

	/**

	 * Constructs a comparison failure.

	 * @param message the identifying message or null

	 * @param expected the expected string value

	 * @param actual the actual string value

	 */

	public ComparisonFailure (String message, String expected, String actual) {

		super (message);

		fExpected= expected;

		fActual= actual;

	}

	/**

	 * Returns "..." in place of common prefix and "..." in

	 * place of common suffix between expected and actual.

	 * 

	 * @see Throwable#getMessage()

	 */

	@Override

	public String getMessage() {

		return new ComparisonCompactor(MAX_CONTEXT_LENGTH, fExpected, fActual).compact(super.getMessage());

	}

	/**

	 * Gets the actual string value

	 * @return the actual string value

	 */

	public String getActual() {

		return fActual;

	}

	/**

	 * Gets the expected string value

	 * @return the expected string value

	 */

	public String getExpected() {

		return fExpected;

	}

}