您可以尝试使用c:catch将字符串隐式转换为数字并捕获任何异常(如果有).例如:

You could try to implicitly cast a string to a number and catch any exception (if there is one) using c:catch. For example:

<c:catch var="catchString">
  <c:set var="myString" value="${0 + 'asd1234'}" />
</c:catch>
<c:if test="${not empty catchString}">
  <p>Failed: ${catchString}</p>
</c:if>

<c:catch var="catchNumber">
  <c:set var="myNumber" value="${0 + '1234'}" />
</c:catch>
<c:if test="${not empty catchNumber}">
  <p>Failed: ${catchNumber}</p>
</c:if>

将输出以下内容:

<p>Failed: java.lang.NumberFormatException: For input string: "asd1234"</p>

如果要防止浮点，可以使用fmt:formatNumber进行检查以检查小数点:

If you want to prevent floats you could build a check using fmt:formatNumber to check for decimals:

<c:set var="myFloat" value="12"/>
<fmt:formatNumber value="${myFloat}" pattern="0" var="myInteger"/>
<c:if test="${myInteger - myFloat eq 0}">
  <p>No decimals</p>
</c:if>

当然，您可以将其与c:catch结合使用以捕获数字格式异常.

Of course you could combine this with the c:catch to catch number format exceptions.

<c:set var="myString" value="abc12.34"/>
<c:catch>
  <fmt:formatNumber value="${myString}" pattern="0" var="myInteger"/>
  <c:set var="passed" value="${myInteger - myString eq 0}"/>
</c:catch>

<c:if test="${passed}">
  <p>Passed</p>
</c:if>

<c:if test="${not passed}">
  <p>Failed</p>
</c:if>