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POStatic Method which uses reflection
 

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    <p>I am currently experimenting with reflection and I recently came across a question. I have this method, which calculates the size (unit: bytes) of a class consisting only of primitive typed fields (excluding booleans) as follows:</p> <pre><code>import java.lang.reflect.Field; public class Foo { // [...] // Works only for classes with primitive typed fields (excluding booleans) public int getSize() { int size = 0; for (Field f : getClass().getDeclaredFields()) { try { f.setAccessible(true); Object obj = f.get(this); Field objField = obj.getClass().getDeclaredField("SIZE"); int fieldSize = (int) objField.get(obj); size += fieldSize / Byte.SIZE; } catch (Exception e) { e.printStackTrace(); } } return size; } } </code></pre> <p>As you can see the method cannot be static, since it contains non-static stuff like <code>getClass()</code> and <code>this</code>. However, for every instance of this class the return value of <code>getSize()</code> will be the same, which also holds for every class which extends <code>Foo</code> (of course, with a different value). Hence, conceptually <code>getSize()</code> has a static nature.</p> <p>Is there a way to make this method static? I thought of using a static class reference like <code>Foo.class</code> to get around <code>getClass()</code> but this would basically destroy the semantics of <code>getSize()</code> for classes which extend <code>Foo</code>. I currently do not think it is possible since static methods are not inherited, but I am not 100% sure if there might be a little tweak to handle this issue.</p>
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    1. COIf you want to make the method static then you have to change it to take an argument of type `Foo`.
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    2. COBoth answers suggesting passing Foo as an argument are valid.; You may also want to consider whether it is in the nature of Foo to have such a method, or whether you would want to externalise it to some utility Class.
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