[RESOLVIDO] Erro JPA JPQL?

Programação Java
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#1

Alguém pode me a ajudar a solucionar esse erro?:

Exception in thread “AWT-EventQueue-0” javax.persistence.NoResultException: getSingleResult() did not retrieve any entities.
at org.eclipse.persistence.internal.jpa.QueryImpl.throwNoResultException(QueryImpl.java:972)
at org.eclipse.persistence.internal.jpa.QueryImpl.getSingleResult(QueryImpl.java:522)
at org.eclipse.persistence.internal.jpa.EJBQueryImpl.getSingleResult(EJBQueryImpl.java:400)
at modelos.UsuariosJpaDAO.getByUsuario(UsuariosJpaDAO.java:43)
at Telas.TelaCadastrar.btnCadastrarActionPerformed(TelaCadastrar.java:138)
at Telas.TelaCadastrar.access$000(TelaCadastrar.java:8)
at Telas.TelaCadastrar$1.actionPerformed(TelaCadastrar.java:44)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2346)
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:6525)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3322)
at java.awt.Component.processEvent(Component.java:6290)
at java.awt.Container.processEvent(Container.java:2234)
at java.awt.Component.dispatchEventImpl(Component.java:4881)
at java.awt.Container.dispatchEventImpl(Container.java:2292)
at java.awt.Component.dispatchEvent(Component.java:4703)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4898)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4533)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4462)
at java.awt.Container.dispatchEventImpl(Container.java:2278)
at java.awt.Window.dispatchEventImpl(Window.java:2739)
at java.awt.Component.dispatchEvent(Component.java:4703)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:751)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:702)
at java.awt.EventQueue$3.run(EventQueue.java:696)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:86)
at java.awt.EventQueue$4.run(EventQueue.java:724)
at java.awt.EventQueue$4.run(EventQueue.java:722)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:721)
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)

Segue o DAO:

package modelos;

import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
import javax.persistence.Query;
  
public class UsuariosJpaDAO {
  
         private static UsuariosJpaDAO instance;
         protected EntityManager entityManager;
          
         public static UsuariosJpaDAO getInstance(){
                   if (instance == null){
                            instance = new UsuariosJpaDAO();
                   }
                    
                   return instance;
         }
  
         public UsuariosJpaDAO() {
                   entityManager = getEntityManager();
         }
  
         public EntityManager getEntityManager() {
                   EntityManagerFactory factory = Persistence.createEntityManagerFactory("usuarios");
                   if (entityManager == null) {
                            entityManager = factory.createEntityManager();
                   }
  
                   return entityManager;
         }
  
         public Usuarios getById(final int id) {
                   return entityManager.find(Usuarios.class, id);
         }
         
         public String getByUsuario(final String usuario) {
             String jpql = "SELECT e.usuario FROM Usuarios e WHERE e.usuario =:user";
             //String jpql = "SELECT e.usuario FROM Usuarios e WHERE e.usuario like ':user'";
		Query query = entityManager.createQuery(jpql);
		query.setParameter("user", usuario);
                return (String) query.getSingleResult();
         }
  
         @SuppressWarnings("unchecked")
         public List<Usuarios> findAll() {
                   return entityManager.createQuery("FROM " + Usuarios.class.getName()).getResultList();
         }
  
         public void persist(Usuarios usuarios) {
                   try {
                            entityManager.getTransaction().begin();
                            entityManager.persist(usuarios);
                            entityManager.getTransaction().commit();
                   } catch (Exception ex) {
                            ex.printStackTrace();
                            entityManager.getTransaction().rollback();
                   }
         }
  
         public void merge(Usuarios usuarios) {
                   try {
                            entityManager.getTransaction().begin();
                            entityManager.merge(usuarios);
                            entityManager.getTransaction().commit();
                   } catch (Exception ex) {
                            ex.printStackTrace();
                            entityManager.getTransaction().rollback();
                   }
         }
  
         public void remove(Usuarios usuarios) {
                   try {
                            entityManager.getTransaction().begin();
                            usuarios = entityManager.find(Usuarios.class, usuarios.getId());
                            entityManager.remove(usuarios);
                            entityManager.getTransaction().commit();
                   } catch (Exception ex) {
                            ex.printStackTrace();
                            entityManager.getTransaction().rollback();
                   }
         }
  
         public void removeById(final int id) {
                   try {
                            Usuarios usuarios = getById(id);
                            remove(usuarios);
                   } catch (Exception ex) {
                            ex.printStackTrace();
                   }
         }
  
}

Esse é meu TCC e estou na dificuldade de cadastrar o usuário no bd, porém antes de efetuar o cadastro deverá fazer a comparação para ver se o login está disponível, segue a programação da tela cadastro:

package Telas;

import modelos.Usuarios;
import java.awt.Toolkit;
import javax.swing.JOptionPane;
import modelos.UsuariosJpaDAO;

public class TelaCadastrar extends javax.swing.JFrame {

    
    public TelaCadastrar() {
        initComponents();
        setIcon();
    }
    
    private void setIcon() {
        setIconImage(Toolkit.getDefaultToolkit().getImage(getClass().getResource("/imagens/icons8-cadeado-2-50.png")));
    }
    
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jPanel1 = new javax.swing.JPanel();
        txtUsuario = new javax.swing.JTextField();
        btnCadastrar = new javax.swing.JButton();
        jLabel4 = new javax.swing.JLabel();
        jLabel5 = new javax.swing.JLabel();
        txtNome = new javax.swing.JTextField();
        jLabel7 = new javax.swing.JLabel();
        cmbCargo = new javax.swing.JComboBox();
        jLabel3 = new javax.swing.JLabel();
        txtSenha = new javax.swing.JPasswordField();

        setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);

        jPanel1.setBorder(javax.swing.BorderFactory.createTitledBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED), "Cadastrar", javax.swing.border.TitledBorder.CENTER, javax.swing.border.TitledBorder.ABOVE_TOP, new java.awt.Font("Times New Roman", 1, 24))); // NOI18N

        btnCadastrar.setFont(new java.awt.Font("Arial", 0, 11)); // NOI18N
        btnCadastrar.setText("Cadastrar");
        btnCadastrar.setCursor(new java.awt.Cursor(java.awt.Cursor.HAND_CURSOR));
        btnCadastrar.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                btnCadastrarActionPerformed(evt);
            }
        });

        jLabel4.setFont(new java.awt.Font("Times New Roman", 0, 14)); // NOI18N
        jLabel4.setText("Nome:");

        jLabel5.setFont(new java.awt.Font("Times New Roman", 0, 14)); // NOI18N
        jLabel5.setText("Usuário:");

        jLabel7.setFont(new java.awt.Font("Times New Roman", 0, 14)); // NOI18N
        jLabel7.setText("Cargo:");

        cmbCargo.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "Coordenador", "Professor" }));
        cmbCargo.setCursor(new java.awt.Cursor(java.awt.Cursor.HAND_CURSOR));

        jLabel3.setFont(new java.awt.Font("Times New Roman", 0, 14)); // NOI18N
        jLabel3.setText("Senha:");

        javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addGap(47, 47, 47)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                        .addComponent(jLabel3)
                        .addComponent(jLabel5)
                        .addComponent(jLabel4))
                    .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 9, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(jLabel7)))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                        .addComponent(txtSenha, javax.swing.GroupLayout.DEFAULT_SIZE, 190, Short.MAX_VALUE)
                        .addComponent(cmbCargo, 0, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                        .addComponent(txtUsuario)
                        .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                            .addComponent(btnCadastrar, javax.swing.GroupLayout.PREFERRED_SIZE, 150, javax.swing.GroupLayout.PREFERRED_SIZE)
                            .addGap(11, 11, 11)))
                    .addComponent(txtNome, javax.swing.GroupLayout.DEFAULT_SIZE, 190, Short.MAX_VALUE))
                .addContainerGap())
        );
        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addGap(35, 35, 35)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(txtNome, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jLabel4))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(txtUsuario, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jLabel5))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(txtSenha, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jLabel3))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel7)
                    .addComponent(cmbCargo, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(28, 28, 28)
                .addComponent(btnCadastrar)
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addContainerGap())
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addContainerGap())
        );

        pack();
    }// </editor-fold>                        

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

        UsuariosJpaDAO dao = new UsuariosJpaDAO();  
        Usuarios cadastro =  new Usuarios();
        
        String usuario = dao.getByUsuario(txtUsuario.getText());
        
        if(usuario.equals(txtUsuario.getText())){
            JOptionPane.showMessageDialog(this, "Erro usuário já existente, por favor tente novamente!");
            txtUsuario.grabFocus();
        }
        else{
            cadastro.setNome(txtNome.getText());
            cadastro.setUsuario(txtUsuario.getText());
            cadastro.setSenha(txtSenha.getText());
            cadastro.setCargo(cmbCargo.getSelectedItem().toString());
        
            dao.persist(cadastro);
            JOptionPane.showMessageDialog(this, "Cadastro realizado com sucesso!");
            limpar();
        }
    }                                            
    
    public void limpar(){
        txtNome.setText("");
        txtSenha.setText("");
        txtUsuario.setText("");
    }
    
    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(TelaCadastrar.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(TelaCadastrar.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(TelaCadastrar.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(TelaCadastrar.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new TelaCadastrar().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify                     
    private javax.swing.JButton btnCadastrar;
    private javax.swing.JComboBox cmbCargo;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JLabel jLabel4;
    private javax.swing.JLabel jLabel5;
    private javax.swing.JLabel jLabel7;
    private javax.swing.JPanel jPanel1;
    private javax.swing.JTextField txtNome;
    private javax.swing.JPasswordField txtSenha;
    private javax.swing.JTextField txtUsuario;
    // End of variables declaration                   
}
#2

Essa exceção como o próprio diz, ela é lançada quando o método getSingleResult não retorna nenhum registro.

Se você não quer tratar a exceção, você pode usar o método getResultList no lugar e então pegar o primeiro elemento da lista

2 curtidas
#3

No caso esse e.usuario seria um nome? caso for e tiver informando um nome esperado e o mesmo estiver no banco de dados pode ser que não esteja encontrando por causa de case sensitivo, diferença de letras maiúsculas e minusculas, você pode contornar essa situação usando a função LOWER(e.usuario) e na configuração do parâmetro também você faz a mesma coisa!

1 curtida
#4

No caso estou apenas querendo fazer uma comparação, se o usuário já existir no banco de dados ele mostrará um erro e não deixará cadastrar, isso está OK. Mas quando o meu banco de dados está vazio ele ou tento cadastrar com um usuário diferente ele me mostrar esse erro, então usando o getResultList resolverá o meu problema?

#5

Tentei utilizar o LOWER mas não obtive sucesso. Esse e.usuario refere-se a minha tupla no banco de dados, o nome do meu registro na tabela.

#6

Eu consegui resolver o problema com a seguinte implementação:

List results = query.getResultList();
        String found = null;
        if(!results.isEmpty()){
            found = (String) results.get(0);
        }
        else{
            found = "usuario não encontrado";
            }
        return found;

Obrigado a todos!

#7

Foi o que eu disse :+1:

#8

Agradeço :+1:

1 curtida