/**
 * Asserts that two ints are equal. 斷言兩個int是相等的
 */
static public void assertEquals(int expected, int actual) {
    assertEquals(null, expected, actual);
}

可以看到里面調(diào)用了assertEquals(String message, int expected, int actual)方法:

/**
 * Asserts that two ints are equal. If they are not
 * an AssertionFailedError is thrown with the given message.
 * 如果不拋出帶有 message 的異常(AssertionFailedError)信息, 則表明兩者相等
 */
static public void assertEquals(String message, int expected, int actual) {
    assertEquals(message, Integer.valueOf(expected), Integer.valueOf(actual));
}

可以看到, 這里把int類型封箱成為Integer類型. 注釋說, 會拋異常, 但這里沒有. 沒關(guān)系, 我們接著看里面調(diào)用: assertEquals(String message, Object expected, Object actual)方法:

/**
 * Asserts that two objects are equal. If they are not
 * an AssertionFailedError is thrown with the given message.
 * 如果不拋出帶有 message 的異常(AssertionFailedError)信息, 則表明兩者相等(這里比較的是Object對象)
 */
static public void assertEquals(String message, Object expected, Object actual) {
    if (expected == null && actual == null) {
        return;
    }
    if (expected != null && expected.equals(actual)) {
        return;
    }
    failNotEquals(message, expected, actual);
}

兩個if語句, 判斷了兩者相等的情況: 引用(地址)相等或者內(nèi)容相等. 如果這兩種if情況都不命中, 那么表明1參和2參實際是不相等, 所以代碼會往下執(zhí)行failNotEquals(String message, Object expected, Object actual)方法，并在此方法中拋出異常, 接下來就比較簡單了:

static public void failNotEquals(String message, Object expected, Object actual) {
    fail(format(message, expected, actual));
}

public static String format(String message, Object expected, Object actual) {
    String formatted = "";
    if (message != null && message.length() > 0) {
        formatted = message + " ";
    }
    return formatted + "expected:<" + expected + "> but was:<" + actual + ">";
}
/**
* Fails a test with the given message.
*/
static public void fail(String message) {
	if (message == null) {
	    throw new AssertionFailedError();
	}
	throw new AssertionFailedError(message);
}

以上可以看出, 最終是由fail(String message)這個方法拋出異常信息!!

Assert.assertEquals()使用方法:

使用, 示例代碼:

Assert.assertEquals(true, arry.contains("hello"));
Assert.assertEquals(39991L, aa.getLong("key3", 0L));
Assert.assertEquals(true, bb.getBoolean("key4", false));
Assert.assertEquals(5.3f, cc.getFloat("key5", 0.f));
Assert.assertEquals(99, dd.getInt("key6", 1));
Assert.assertEquals("如果打印本信息, 證明參數(shù)不相等", 10L, 10);

按照源碼分析, 我們可以把一個預期結(jié)果作為1參傳遞進去. 2參傳遞我們需要測試的方法. 然后執(zhí)行. 相等, 代碼繼續(xù)往下執(zhí)行, 不相等, 中斷執(zhí)行, 拋出異常信息!!!

略作一提:

Assert.assertSame(Object expected, Object actual)方法:

其比較的是引用地址是否相等, 并沒有對內(nèi)容進行比較:

/**
 * Asserts that two objects refer to the same object. If they are not
 * the same an AssertionFailedError is thrown.
 */
static public void assertSame(Object expected, Object actual) {
    assertSame(null, expected, actual);
}
/**
 * Asserts that two objects refer to the same object. If they are not
 * an AssertionFailedError is thrown with the given message.
 */
static public void assertSame(String message, Object expected, Object actual) {
    if (expected == actual) {
        return;
    }
    failNotSame(message, expected, actual);
}

到此這篇關(guān)于Assert.assertEquals()方法參數(shù)詳解的文章就介紹到這了。希望對大家的學習有所幫助，也希望大家多多支持腳本之家。

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