Carregar Cobobox Banco de dados

Assuntos Gerais
#1

Estou fazendo uma consulta no meu banco de dados sem paramentros, pois o retorno sera tudo que tem na tabela de estados.


public ArrayList<Estado> getLista() throws SQLException{
        
    	
    	
    	String sql = "SELECT * FROM tb_estados";  
        PreparedStatement stmt = this.conexao.prepareStatement(sql);  
        ResultSet rs = stmt.executeQuery();  
  
        List minhalista = new ArrayList<Estado>();  
        
        while (rs.next()){  
        	Estado cad = new Estado(); 
        	 
        	        	
           cad.setEstado(rs.getString("fi_estado"));//(rs.getString("nome")); 
           
          
           minhalista.add(cad);
        }  
         
        rs.close();  
        stmt.close();  
    
        return  (ArrayList<Estado>) minhalista;  
    }

	

}



public void carregaCombo() throws SQLException
	{
	
		 cbEstado.removeAllItems();
		 cbEstado.addItem(" ");
		 EstadoDao dao= new EstadoDao();
        try {  
        	String str = null;
           ArrayList<Estado> minhalista = dao.getLista();  
         
            for (int i = 0; i < minhalista.size(); i++) {  
            	str =(String)minhalista.get(i).toString();
            	System.out.println(str);
                cbEstado.addItem(str);  
                	
              System.out.println(minhalista.get(i).getEstado());
            }  
            //cbEstado = new JComboBox();
          cbEstado.updateUI();
            //cbEstado = new JComboBox();  
        } catch (SQLException ex) {  
            JOptionPane.showMessageDialog(null,"Erro  ! " + ex);  
        }  
	  
	    }

Erro apresentado




Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
	at controle.gui.cadastro.endereco.JiCidade.carregaCombo(JiCidade.java:153)
	at controle.gui.cadastro.endereco.JiCidade$1.mouseReleased(JiCidade.java:98)
	at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:273)
	at java.awt.Component.processMouseEvent(Component.java:6288)
	at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
	at java.awt.Component.processEvent(Component.java:6053)
	at java.awt.Container.processEvent(Container.java:2041)
	at java.awt.Component.dispatchEventImpl(Component.java:4651)
	at java.awt.Container.dispatchEventImpl(Container.java:2099)
	at java.awt.Component.dispatchEvent(Component.java:4481)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4577)
	at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238)
	at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168)
	at java.awt.Container.dispatchEventImpl(Container.java:2085)
	at java.awt.Window.dispatchEventImpl(Window.java:2478)
	at java.awt.Component.dispatchEvent(Component.java:4481)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:643)
	at java.awt.EventQueue.access$000(EventQueue.java:84)
	at java.awt.EventQueue$1.run(EventQueue.java:602)
	at java.awt.EventQueue$1.run(EventQueue.java:600)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
	at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
	at java.awt.EventQueue$2.run(EventQueue.java:616)
	at java.awt.EventQueue$2.run(EventQueue.java:614)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:613)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
	at controle.gui.cadastro.endereco.JiCidade.carregaCombo(JiCidade.java:153)
	at controle.gui.cadastro.endereco.JiCidade$1.mouseReleased(JiCidade.java:98)
	at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:273)
	at java.awt.Component.processMouseEvent(Component.java:6288)
	at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
	at java.awt.Component.processEvent(Component.java:6053)
	at java.awt.Container.processEvent(Container.java:2041)
	at java.awt.Component.dispatchEventImpl(Component.java:4651)
	at java.awt.Container.dispatchEventImpl(Container.java:2099)
	at java.awt.Component.dispatchEvent(Component.java:4481)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4577)
	at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238)
	at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168)
	at java.awt.Container.dispatchEventImpl(Container.java:2085)
	at java.awt.Window.dispatchEventImpl(Window.java:2478)
	at java.awt.Component.dispatchEvent(Component.java:4481)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:643)
	at java.awt.EventQueue.access$000(EventQueue.java:84)
	at java.awt.EventQueue$1.run(EventQueue.java:602)
	at java.awt.EventQueue$1.run(EventQueue.java:600)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
	at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
	at java.awt.EventQueue$2.run(EventQueue.java:616)
	at java.awt.EventQueue$2.run(EventQueue.java:614)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:613)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
#2

tente assim

List minhalista = new ArrayList();

#3

Colega

Fiz a correção mas o erro continua.

#4

experimente setar o objeto ao inves de setar uma string

            str =(String)minhalista.get(i).toString();  
            System.out.println(str);  
            cbEstado.addItem(str);

para

          estado.setEstado(minhalista.get(i));  
            System.out.println(estado.getEstado());  
            cbEstado.addItem(estado);
#5

jorgereidinaldo.
Faz o seguinte:
Muda:

public ArrayList&lt;Estado&gt; getLista() throws SQLException{

para:

public List&lt;Estado&gt; getLista() throws SQLException{

Muda:

para:

Muda também:

para:

Faz essas mudanças, para ver se vai dar certo.
Pode ser que tenha que alterar mais alguma linha.

#6

Pelo que parece, a variável “minhaLista” está null. Por isso o nullPointerException.

Verifique o conteúdo dela.

#7