@Test
public void testGetPropertyNamesPropertiesString01() throws Exception {

    // 入力値の設定
    String key1 = "SystemExceptionHandlerTest.key";
    String value1 = "{0}message";
    Properties input = new Properties();
    input.setProperty(key1, value1);
    String keyprefix = "System";
    // テスト対象の実行
    Enumeration<String> result = PropertyUtil.getPropertyNames(input,
            keyprefix);
    // 結果確認
    Set<String> set = new HashSet<String>();
    set.add("SystemExceptionHandlerTest.key");
    assertTrue(set.contains(result.nextElement()));
    assertFalse(result.hasMoreElements());
}