Java – JSP bean tag for attributes that may not exist

In JSP, I can use tags to reference bean properties

Is there a way to deal with attributes that may not exist? I have a JSP page that needs to handle different types Example:

public class Person {
    public String getName()
}
public class Employee extends Person {
    public float getSalary()
}

In JSP, I want to display a personnel table with name and salary column If the person is not an employee, the salary should be blank The HTML line might look like this:

<tr>
    <td><c:out value="${person.name}"></td>
    <td><c:out value="${person.salary}"></td>
</tr>

Unfortunately, if someone is not an employee, they can't find a salary and make mistakes How can I solve this problem in JSP?

Edit: is there a JSP tag language check instance?

Solution

Just use the El null operator. If it is a scope attribute, unfortunately, you must use employee Salary and < C: catch > to surround your expression:

<c:catch var="err">
    <c:out value="${employee.salary}"/>
</c:catch>

If you really need instanceof, consider using custom tags