struts2中if标签中字符串比较的正确写法 错误写法：
<s:if test="aStringProperty == 'A'"> Why doesn't this work when myString is equal to A?</s:if>
<s:if test='aStringProperty == "A"'> This works!</s:if><s:if test="aStringProperty == "A""> This works too!</s:if>
