spring validator @Pattern doesn't work on Integer
<p>I am trying a simple pattern validation:</p>

<pre><code>@Min(value = 0, message = "invalid.amount")
@Pattern(regexp = "[0-9]+", message = "invalid.amount")
private double amount;
</code></pre>

<p>But it gives the error like: </p>

<pre><code>org.hibernate.validator.internal.engine.constraintvalidation.ConstraintTree.throwExceptionForNullValidator(ConstraintTree.java:229)
</code></pre>

<p>But this works perfectly fine:</p>

<pre><code>@Pattern(regexp = "[\\w|-]{1,5}")
private String data;
</code></pre>

<p>It seems regex doesn't work on number types.</p>