Ao invés de eu usar o JFrame eu usei um JtabbedPane e depois um Jpanel, eu sei q o código esta um pouco ruim, pois o netbeans q gera sozinho e não tenho muita pratica no netbeans.
Bom vou postar o código mais completo aqui em baixo para um maior entendimento, o botão que eu estou tentando inserir se chama “btnSalvarComposicao” e o Jpanel que eu tento inserir o mesmo se chama “pComposicao”.
javax.swing.GroupLayout pComposicaoLayout = new javax.swing.GroupLayout(pComposicao);
pComposicao.setLayout(pComposicaoLayout);
pComposicaoLayout.setHorizontalGroup(
pComposicaoLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(pComposicaoLayout.createSequentialGroup()
.addContainerGap()
.addGroup(pComposicaoLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(pComposicaoLayout.createSequentialGroup()
.addGroup(pComposicaoLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
.addGroup(pComposicaoLayout.createSequentialGroup()
.addGroup(pComposicaoLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
.addComponent(lbCompProdDesc, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(lbCompProdCod, javax.swing.GroupLayout.DEFAULT_SIZE, 105, Short.MAX_VALUE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(pComposicaoLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(tfCompProdDesc, javax.swing.GroupLayout.PREFERRED_SIZE, 153, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(tfCompProdCod, javax.swing.GroupLayout.PREFERRED_SIZE, 153, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addGroup(pComposicaoLayout.createSequentialGroup()
.addComponent(lbCompProdQuant, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 53, Short.MAX_VALUE)
.addGroup(pComposicaoLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(btnSalvarComposicao, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(tfCompProdQuant, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.PREFERRED_SIZE, 153, javax.swing.GroupLayout.PREFERRED_SIZE))))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(tfCompProdUnidade, javax.swing.GroupLayout.PREFERRED_SIZE, 70, javax.swing.GroupLayout.PREFERRED_SIZE))
.addComponent(spComposicao, javax.swing.GroupLayout.PREFERRED_SIZE, 630, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(lbComposicao, javax.swing.GroupLayout.PREFERRED_SIZE, 124, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(ckComposto))
.addContainerGap(330, javax.swing.GroupLayout.PREFERRED_SIZE))
);
pComposicaoLayout.setVerticalGroup(
pComposicaoLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(pComposicaoLayout.createSequentialGroup()
.addContainerGap()
.addComponent(lbComposicao, javax.swing.GroupLayout.PREFERRED_SIZE, 23, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(ckComposto)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(pComposicaoLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(lbCompProdCod, javax.swing.GroupLayout.PREFERRED_SIZE, 17, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(tfCompProdCod, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(pComposicaoLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(lbCompProdDesc, javax.swing.GroupLayout.PREFERRED_SIZE, 17, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(tfCompProdDesc, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(pComposicaoLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(tfCompProdQuant, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(lbCompProdQuant, javax.swing.GroupLayout.PREFERRED_SIZE, 17, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(tfCompProdUnidade, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(18, 18, 18)
.addComponent(btnSalvarComposicao)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 32, Short.MAX_VALUE)
.addComponent(spComposicao, javax.swing.GroupLayout.PREFERRED_SIZE, 308, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap())
);
btnSalvarComposicao.getAccessibleContext().setAccessibleParent(null);
abas.addTab("Composição", pComposicao);
pComposicao.getAccessibleContext().setAccessibleParent(null);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
this.setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(btnSalvar)
.addGap(18, 18, 18)
.addComponent(btnConsultar)
.addGap(18, 18, 18)
.addComponent(btnLimpar)
.addContainerGap(676, Short.MAX_VALUE))
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(abas, javax.swing.GroupLayout.PREFERRED_SIZE, 975, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap(588, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(btnSalvar)
.addComponent(btnConsultar)
.addComponent(btnLimpar))
.addContainerGap())
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(abas, javax.swing.GroupLayout.PREFERRED_SIZE, 558, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(53, Short.MAX_VALUE)))
);
}// </editor-fold>