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copied!<p>Lets look at that "line":</p> <pre><code> if (by >= bricks[0].y && by <= bricks[0].y + bricks[0].img.getHeight(null) && bx >= bricks[0].x && bx <= bricks[0].x + bricks[0].img.getWidth(null)) { </code></pre> <p>Assuming that <code>bx</code>, <code>by</code>, and the <code>x</code> and <code>y</code> fields are all primitive types (e.g. <code>int</code>), then here's a list of things that <em>could</em> result in an NPE:</p> <ul> <li>the <code>bricks</code> variable is <code>null</code></li> <li>the zeroth element of <code>bricks</code> is <code>null</code></li> <li>the value of <code>bricks[0].img</code> is <code>null</code></li> </ul> <p>If <code>bx</code>, <code>by</code>, <code>x</code> and/or <code>y</code> is a wrapper type, then one of those could be <code>null</code>. That would lead to an NPE when unboxing the value.</p> <p>It is not caused by passing <code>null</code> to the <code>getHeight</code> or <code>getWidth</code> methods, because 1) I believe that is valid and 2) if it wasn't then the NPE would be thrown in a different place to what you stacktrace shows.</p> <p>(I can't tell if passing <code>null</code> in those calls is <em>correct</em> ... but either way, it is not the cause of this NPE based on the evidence you have provided.)</p> <hr> <p>If you want to figure what is <em>actually</em> causing the problem, debug the code or add some traceprints to <em>test</em> which of the things that could be <code>null</code> is actually <code>null</code>.</p>

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