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javaspring-bootthymeleaf

Percentage calculation in Thymeleaf - resulting in zero

We have a java object:

class Course{

    long totalStudens;
    long graduatedStudents;
}

And in the Thymeleaf page we like to show the percentage of graduatedStudents out of the totalStudens

So we did something like that but we keep on getting 0 in the result, even when the result should not be zero:

<div th:with="result=${#numbers.formatDecimal((course.graduatedStudents/course.totalStudens)*100, 1, 'POINT', 2, 'COMMA')}">
      <td th:text="${result}"></td>
 </div>

We also tried something simpler:

 <td th:text="${#numbers.formatDecimal(course.graduatedStudents/course.totalStudends, 1, 'POINT', 2, 'COMMA')}"></td>

Is it something to do with the long and double issues? And if so, how to solve it? We prefer to do it in the Thymeleaf side and not in the java side

Solution

  • Since you are doing long/long division the result will be long. If you want to receive floating point precision result you will have to convert one of the factors to double for example by multiplying it by 1.0 :

    <div th:with="result=${#numbers.formatDecimal((1.0 * course.graduatedStudents / course.totalStudens)*100, 1, 'POINT', 2, 'COMMA')}">
    <td th:text="${result}"></td>
</div>