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copied!<p>In order to access private fields, you need to get them from the class's <em>declared</em> fields and then make them accessible:</p> <pre><code>Field f = obj.getClass().getDeclaredField("stuffIWant"); //NoSuchFieldException f.setAccessible(true); Hashtable iWantThis = (Hashtable) f.get(obj); //IllegalAccessException </code></pre> <p><strong>EDIT</strong>: as has been commented by <em>aperkins</em>, both accessing the field, setting it as accessible and retrieving the value will all throw <code>Exception</code>s, although the only <em>checked</em> exceptions you need to be mindful of are commented above.</p> <p>The <code>NoSuchFieldException</code> would be thrown if you asked for a field by a name which did not correspond to a declared field. </p> <pre><code>obj.getClass().getDeclaredField("misspelled"); //will throw NoSuchFieldException </code></pre> <p>The <code>IllegalAccessException</code> would be thrown if the field was not accessible (for example, if it is private and has not been made accessible via missing out the <code>f.setAccessible(true)</code> line.</p> <p>The <code>RuntimeException</code>s which may be thrown are either <code>SecurityException</code>s (if the JVM's <code>SecurityManager</code> will not allow you to change a field's accessibility), or <code>IllegalArgumentException</code>s, if you try and access the field on an object not of the field's class's type:</p> <pre><code>f.get("BOB"); //will throw IllegalArgumentException, as String is of the wrong type </code></pre>

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