Exception in thread "AWT-EventQueue-0" java.lang.IllegalStateException: javax.swing.JButton

I need to solve this error.

The window that i need to register the beer is not openning.

I'm creating a simple system where we can register and search beer's aparrently.

Here is the code.

package cadastro;

import java.awt.Container;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.IOException;
import javax.swing.JButton;
import javax.swing.JFrame;


public class Entrada extends JFrame {

private static final long serialVersionUID = 42L;
private final Container container;
private final JButton btCadastrar;
private final JButton btPesquisar;
private final JButton btSair;

public Entrada() {

    super("Sistema de Avaliação de Cervejas");
    container = getContentPane();
    container.setLayout(new GridLayout(0,1));
    GerenciadorBotoes btManager = new GerenciadorBotoes();

    btCadastrar = new JButton();  
    btPesquisar = new JButton();
    btSair = new JButton();

    btCadastrar.setText("Cadastrar Cervejas");
    btCadastrar.setActionCommand("1");
    btPesquisar.setText("Pesquisar Cervejas");
    btPesquisar.setActionCommand("2");
    btSair.setText("Sair");
    btSair.setActionCommand("3");

    btCadastrar.addActionListener(btManager);
    btPesquisar.addActionListener(btManager);
    btSair.addActionListener(btManager);

    container.add(btCadastrar);
    container.add(btPesquisar);
    container.add(btSair);

    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

setBounds(new java.awt.Rectangle(300, 150, 0, 0));

    setSize(300, 200);
setResizable(false);

}

private class GerenciadorBotoes implements ActionListener {

     @Override
    public void actionPerformed(ActionEvent e) {
        if (null != e.getActionCommand()) {
            if ("1".equals(e.getActionCommand())) {
                new Cadastra().setVisible(true);
            } else {
                if ("2".equals(e.getActionCommand())) {
                    new Pesquisar().setVisible(true);
                }
                else {
                }
            }
        }
    }
}

static void abrir() {
try {
        Acervo.getInstance().open(new File("agenda.poo"));
} catch (IOException | ClassNotFoundException e) {
}
}

public static void main(String args[]) {
Entrada.abrir();
java.awt.EventQueue.invokeLater(new Runnable() {
        @Override
        public void run() {
    new Entrada().setVisible(true);
        }
});
}

}

and here the other.

package cadastro;

import javax.swing.JFrame;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JScrollPane;
import javax.swing.JComboBox;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.JOptionPane;


public class Cadastra extends JFrame {

private final int id = 0;

private JButton btCadastrar;
private JButton btLimpar;
private JLabel lbNome;
private JLabel lbEmpresa;
private JLabel lbTipo;
private JLabel lbNota;
private JLabel lbComentario;
private JScrollPane scrollComent;
private JComboBox cbNota;
private JTextArea tfComentario;
private JTextField tfEmpresa;
private JTextField tfTipo;
private JTextField tfNome;

public Cadastra() {
    initComponents();
}

private void initComponents() {

    lbNome = new JLabel();
    tfNome = new JTextField();
    lbEmpresa = new JLabel();
    tfEmpresa = new JTextField();
    lbTipo = new JLabel();
    tfTipo = new JTextField();
    lbNota = new JLabel();
    lbComentario = new JLabel();
    scrollComent = new JScrollPane();
    tfComentario = new JTextArea();
    cbNota = new JComboBox();
    btCadastrar = new JButton();
    btLimpar = new JButton();

    setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);
    setTitle("Cadastrar");
    setBounds(new java.awt.Rectangle(300, 150, 0, 0));
    setPreferredSize(new java.awt.Dimension(700, 452));
    setResizable(false);
    addWindowListener(new java.awt.event.WindowAdapter() {

        @Override
        public void windowClosing(java.awt.event.WindowEvent evt) {
            windowClose(evt);
        }
    });

    lbNome.setText("Nome da Cerveja");
    lbEmpresa.setText("Empresa");

    tfEmpresa.addActionListener(new java.awt.event.ActionListener() {
        @Override
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            txtnaActionPerformed(evt);
        }
    });

    lbTipo.setText("Tipo");
    lbNota.setText("Nota");
    lbComentario.setText("Comentário");

    tfComentario.setColumns(20);
    tfComentario.setRows(5);
    scrollComent.setViewportView(tfComentario);

    cbNota.setModel(new javax.swing.DefaultComboBoxModel(new String[]{"1", "2", "3", "4", "5", "6", "7", "8", "9", "10"}));
    cbNota.addActionListener(new java.awt.event.ActionListener() {
        @Override
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            notaActionPerformed(evt);
        }
    });

    btCadastrar.setText("Cadastrar");
    btCadastrar.addActionListener(new java.awt.event.ActionListener() {
        @Override
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            jButton1ActionPerformed(evt);
        }
    });

    btLimpar.setText("Limpar");
    btLimpar.addActionListener(new java.awt.event.ActionListener() {
        @Override
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            jButton2ActionPerformed(evt);
        }
    });

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createSequentialGroup()
                            .addContainerGap()
                            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                                    .addGroup(layout.createSequentialGroup()
                                            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).
                                                    addGroup(layout.createSequentialGroup()
                                                            .addComponent(lbNome)
                                                            .addGap(18, 18, 18)
                                                            .addComponent(tfNome, javax.swing.GroupLayout.PREFERRED_SIZE, 130, javax.swing.GroupLayout.PREFERRED_SIZE))
                                                    .addGroup(layout.createSequentialGroup()
                                                            .addComponent(lbTipo)
                                                            .addGap(18, 18, 18)
                                                            .addComponent(tfTipo, javax.swing.GroupLayout.PREFERRED_SIZE, 130, javax.swing.GroupLayout.PREFERRED_SIZE)))
                                            .addGap(79, 79, 79)
                                            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                                                    .addGroup(layout.createSequentialGroup()
                                                            .addComponent(lbNota)
                                                            .addGap(18, 18, 18)
                                                            .addComponent(cbNota, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                                                            .addGap(173, 173, 173))
                                                    .addGroup(layout.createSequentialGroup()
                                                            .addComponent(lbEmpresa)
                                                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                                                            .addComponent(tfEmpresa, javax.swing.GroupLayout.DEFAULT_SIZE, 149, Short.MAX_VALUE)
                                                            .addContainerGap())))
                                    .addGroup(layout.createSequentialGroup()
                                            .addComponent(lbComentario)
                                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                            .addComponent(scrollComent)
                                            .addGap(18, 18, 18)
                                            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                                                    .addComponent(lbEmpresa)
                                                    .addComponent(lbNome))
                                            .addGap(82, 82, 82)))));
    layout.linkSize(javax.swing.SwingConstants.HORIZONTAL, new java.awt.Component[]{btCadastrar, btLimpar});
    layout.setVerticalGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                    .addContainerGap()
                    .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                            .addComponent(lbNome)
                            .addComponent(tfNome, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                            .addComponent(lbEmpresa)
                            .addComponent(tfEmpresa, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addGap(26, 26, 26)
                    .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                            .addComponent(lbTipo)
                            .addComponent(tfTipo, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                            .addComponent(lbNota)
                            .addComponent(cbNota, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addGap(30, 30, 30)
                    .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(lbComentario)
                            .addGroup(layout.createSequentialGroup()
                                    .addGap(25, 25, 25)
                                    .addComponent(btCadastrar)
                                    .addGap(30, 30, 30)
                                    .addComponent(btLimpar))
                            .addComponent(scrollComent, javax.swing.GroupLayout.PREFERRED_SIZE, 125, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addContainerGap(150, Short.MAX_VALUE)));
    pack();
}

private void notaActionPerformed(java.awt.event.ActionEvent evt) {
    //
}

private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) { // Apaga os caracteres escritos                                     
    tfNome.setText("");
    tfEmpresa.setText("");
    tfTipo.setText("");
    tfComentario.setText("");
    cbNota.setSelectedIndex(0);
}

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) { // Gravar os dados cadastrados

    String nome = tfNome.getText();
    String nomeEmpresa = tfEmpresa.getText();
    String tipo = tfTipo.getText();
    String comentario = tfComentario.getText();
    int selecionado = cbNota.getSelectedIndex();
    String Snota = Integer.toString(selecionado + 1);

    if (nome == null || nome.trim().equals("")) { // Se o nome for null ou o nome, retirando os espaços em branco, for igual a ""
        JOptionPane.showMessageDialog(this, "Não foi possível adicionar. Forneça o nome da Cerveja!", "Erro", JOptionPane.ERROR_MESSAGE);
    } else {
        boolean temCerveja = Acervo.getInstance().temCerveja(nome);
        if (temCerveja) {
        JOptionPane.showMessageDialog(this, "Não foi possível adicionar. Cerveja com mesmo nome já cadastrado!", "Aviso", JOptionPane.WARNING_MESSAGE);
        } else {
        CervejaAtual cerveja = new CervejaAtual(nome ,nomeEmpresa,tipo , comentario, Snota);
        Acervo acervo = Acervo.getInstance();
        acervo.addCerveja(cerveja);

        JOptionPane.showMessageDialog(this, "Adicionado com sucesso!", "Informação", JOptionPane.INFORMATION_MESSAGE);
        this.dispose();
        }
    }   
}

private void txtnaActionPerformed(java.awt.event.ActionEvent evt) {

}

private void windowClose(java.awt.event.WindowEvent evt) {

}

}

The error.

Exception in thread "AWT-EventQueue-0" java.lang.IllegalStateException: javax.swing.JButton[,0,0,0x0,invalid,alignmentX=0.0,alignmentY=0.5,border=javax.swing.plaf.BorderUIResource$CompoundBorderUIResource@7e83ef0,flags=296,maximumSize=,minimumSize=,preferredSize=,defaultIcon=,disabledIcon=,disabledSelectedIcon=,margin=javax.swing.plaf.InsetsUIResource[top=2,left=14,bottom=2,right=14],paintBorder=true,paintFocus=true,pressedIcon=,rolloverEnabled=true,rolloverIcon=,rolloverSelectedIcon=,selectedIcon=,text=Limpar,defaultCapable=true] is not attached to a horizontal group
at javax.swing.GroupLayout.checkComponents(GroupLayout.java:1086)
at javax.swing.GroupLayout.prepare(GroupLayout.java:1040)
at javax.swing.GroupLayout.layoutContainer(GroupLayout.java:910)
at java.awt.Container.layout(Container.java:1510)
at java.awt.Container.doLayout(Container.java:1499)
at java.awt.Container.validateTree(Container.java:1695)
at java.awt.Container.validateTree(Container.java:1704)
at java.awt.Container.validateTree(Container.java:1704)
at java.awt.Container.validateTree(Container.java:1704)
at java.awt.Container.validate(Container.java:1630)
at java.awt.Container.validateUnconditionally(Container.java:1667)
at java.awt.Window.pack(Window.java:818)
at cadastro.Cadastra.initComponents(Cadastra.java:173)
at cadastro.Cadastra.<init>(Cadastra.java:36)
at cadastro.Entrada$GerenciadorBotoes.actionPerformed(Entrada.java:66)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6535)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
at java.awt.Component.processEvent(Component.java:6300)
at java.awt.Container.processEvent(Container.java:2236)
at java.awt.Component.dispatchEventImpl(Component.java:4891)
at java.awt.Container.dispatchEventImpl(Container.java:2294)
at java.awt.Component.dispatchEvent(Component.java:4713)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4525)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466)
at java.awt.Container.dispatchEventImpl(Container.java:2280)
at java.awt.Window.dispatchEventImpl(Window.java:2750)
at java.awt.Component.dispatchEvent(Component.java:4713)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)
at java.awt.EventQueue$4.run(EventQueue.java:731)
at java.awt.EventQueue$4.run(EventQueue.java:729)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

These lines:

.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                                                .addComponent(lbEmpresa)
                                                .addComponent(lbNome))

and these lines:

               .addGroup(layout.createSequentialGroup()
                            .addGap(25, 25, 25)
                            .addComponent(btCadastrar)
                            .addGap(30, 30, 30)
                            .addComponent(btLimpar))

you have to change lbEmpresa and lbNome to btCadastrar and btLimpar.