Java:How to align JPanels

开发者_如何学JAVAI have this code but it doesn't work:

jPanel1.add(jLabel1);
jPanel2.add(jButton1);
jPanel2.add(jButton2);
jPanel3.add(jPanel1,jPanel1.TOP_ALIGNMENT);
jPanel3.add(jPanel2,jPanel2.BOTTOM_ALIGNMENT);
setContentPane(jPanel3);

pack();

Please tell me why!

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You're not setting a LayoutManager on any of the panels. This tutorial may be of use to you