Discussoes de Programacao e Tecnologia

Try e catch

9 respostas
fabiobufalari
fabiobufalari

pessoal preciso de lançar uma exceção com try e catch pra nao aceitar letras como posso fazeer ?
estou sem saber como devo fazer to lascado!!!
valeuu.

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

/*
 * JFCalc.java
 *
 * Created on 06/06/2011, 20:34:19
 */

package calculadora;

/**
 *
 * @author Fabio
 */
public class JFCalc extends javax.swing.JFrame {

    char operacao;
    int cont,result;
    String temp,numeroAntes;
    Double num1,num2,resultado;



    /** Creates new form JFCalc */
    public JFCalc() {
        initComponents();
    }

    private void escolheOperacao(char op) throws NumberFormatException {
        operacao = op;
        num1 = Double.parseDouble(jTVisor.getText());
        jTVisor.setText("");
    }

    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jPanel1 = new javax.swing.JPanel();
        jTVisor = new javax.swing.JTextField();
        jBCe = new javax.swing.JButton();
        jB9 = new javax.swing.JButton();
        jB5 = new javax.swing.JButton();
        jB1 = new javax.swing.JButton();
        jB0 = new javax.swing.JButton();
        jBBackSpace = new javax.swing.JButton();
        jBSubtracaoAdicao = new javax.swing.JButton();
        jB6 = new javax.swing.JButton();
        jB2 = new javax.swing.JButton();
        jBPonto = new javax.swing.JButton();
        jBClr = new javax.swing.JButton();
        jBSubtracao = new javax.swing.JButton();
        jBMultiplicacao = new javax.swing.JButton();
        jBDivisao = new javax.swing.JButton();
        jB7 = new javax.swing.JButton();
        jB8 = new javax.swing.JButton();
        jB3 = new javax.swing.JButton();
        jB4 = new javax.swing.JButton();
        jBIgual = new javax.swing.JButton();
        jBAdicao = new javax.swing.JButton();
        jBSubtracaoAdicao1 = new javax.swing.JButton();
        jBDivisao1 = new javax.swing.JButton();
        jBMultiplicacao1 = new javax.swing.JButton();
        jBSubtracao1 = new javax.swing.JButton();
        jBPotencia = new javax.swing.JButton();
        jMenuBar1 = new javax.swing.JMenuBar();
        jMenu1 = new javax.swing.JMenu();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        setTitle("Calculadora RuWindows");

        jTVisor.setFont(new java.awt.Font("Tahoma", 1, 14));
        jTVisor.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jTVisorActionPerformed(evt);
            }
        });

        jBCe.setText("CE");
        jBCe.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jBCeActionPerformed(evt);
            }
        });

        jB9.setText("9");
        jB9.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jB9ActionPerformed(evt);
            }
        });

        jB5.setText("5");
        jB5.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jB5ActionPerformed(evt);
            }
        });

        jB1.setText("1");
        jB1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jB1ActionPerformed(evt);
            }
        });

        jB0.setText("0");
        jB0.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jB0ActionPerformed(evt);
            }
        });

        jBBackSpace.setText("Bep");
        jBBackSpace.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jBBackSpaceActionPerformed(evt);
            }
        });

        jBSubtracaoAdicao.setText("- +");

        jB6.setText("6");
        jB6.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jB6ActionPerformed(evt);
            }
        });

        jB2.setText("2");
        jB2.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jB2ActionPerformed(evt);
            }
        });

        jBPonto.setText(".");
        jBPonto.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jBPontoActionPerformed(evt);
            }
        });

        jBClr.setText("CLR");
        jBClr.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jBClrActionPerformed(evt);
            }
        });

        jBSubtracao.setText("-");
        jBSubtracao.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jBSubtracaoActionPerformed(evt);
            }
        });

        jBMultiplicacao.setText("*");
        jBMultiplicacao.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jBMultiplicacaoActionPerformed(evt);
            }
        });

        jBDivisao.setText("/");
        jBDivisao.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jBDivisaoActionPerformed(evt);
            }
        });

        jB7.setText("7");
        jB7.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jB7ActionPerformed(evt);
            }
        });

        jB8.setText("8");
        jB8.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jB8ActionPerformed(evt);
            }
        });

        jB3.setText("3");
        jB3.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jB3ActionPerformed(evt);
            }
        });

        jB4.setText("4");
        jB4.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jB4ActionPerformed(evt);
            }
        });

        jBIgual.setText("=");
        jBIgual.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jBIgualActionPerformed(evt);
            }
        });

        jBAdicao.setText("+");
        jBAdicao.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jBAdicaoActionPerformed(evt);
            }
        });

        jBDivisao1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jBDivisao1ActionPerformed(evt);
            }
        });

        jBMultiplicacao1.setText("Raiz");
        jBMultiplicacao1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jBMultiplicacao1ActionPerformed(evt);
            }
        });

        jBSubtracao1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jBSubtracao1ActionPerformed(evt);
            }
        });

        jBPotencia.setText("Potencia");
        jBPotencia.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jBPotenciaActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                    .addComponent(jTVisor, javax.swing.GroupLayout.PREFERRED_SIZE, 227, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                                .addComponent(jB1)
                                .addComponent(jB4))
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                                .addGroup(jPanel1Layout.createSequentialGroup()
                                    .addComponent(jB5)
                                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                                    .addComponent(jB6))
                                .addGroup(jPanel1Layout.createSequentialGroup()
                                    .addComponent(jB2)
                                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                                    .addComponent(jB3)))
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                                .addComponent(jBSubtracao)
                                .addComponent(jBMultiplicacao)))
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addComponent(jB0)
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                            .addComponent(jBPonto)
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                            .addComponent(jBIgual)
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                            .addComponent(jBAdicao))
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                                .addComponent(jB7)
                                .addComponent(jBCe, javax.swing.GroupLayout.PREFERRED_SIZE, 65, javax.swing.GroupLayout.PREFERRED_SIZE))
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                                .addGroup(jPanel1Layout.createSequentialGroup()
                                    .addComponent(jBBackSpace)
                                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                                    .addComponent(jBClr)
                                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                    .addComponent(jBSubtracaoAdicao))
                                .addGroup(jPanel1Layout.createSequentialGroup()
                                    .addComponent(jB8)
                                    .addGap(10, 10, 10)
                                    .addComponent(jB9)
                                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                    .addComponent(jBDivisao))))))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                    .addComponent(jBMultiplicacao1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(jBSubtracao1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(jBDivisao1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(jBSubtracaoAdicao1, javax.swing.GroupLayout.DEFAULT_SIZE, 63, Short.MAX_VALUE)
                    .addComponent(jBPotencia))
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );

        jPanel1Layout.linkSize(javax.swing.SwingConstants.HORIZONTAL, new java.awt.Component[] {jB0, jB1, jB2, jB3, jB4, jB5, jB6, jB7, jB8, jB9, jBAdicao, jBBackSpace, jBCe, jBClr, jBDivisao, jBIgual, jBMultiplicacao, jBPonto, jBSubtracao, jBSubtracaoAdicao});

        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                .addComponent(jTVisor, javax.swing.GroupLayout.PREFERRED_SIZE, 42, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                        .addComponent(jBSubtracaoAdicao1, javax.swing.GroupLayout.DEFAULT_SIZE, 31, Short.MAX_VALUE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(jBDivisao1, javax.swing.GroupLayout.PREFERRED_SIZE, 31, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                        .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                            .addComponent(jBCe)
                            .addComponent(jBBackSpace)
                            .addComponent(jBClr)
                            .addComponent(jBSubtracaoAdicao))
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                            .addComponent(jB8)
                            .addComponent(jB7)
                            .addComponent(jBDivisao)
                            .addComponent(jB9))))
                .addGap(12, 12, 12)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jB5)
                    .addComponent(jB6)
                    .addComponent(jB4)
                    .addComponent(jBMultiplicacao)
                    .addComponent(jBSubtracao1, javax.swing.GroupLayout.PREFERRED_SIZE, 31, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(14, 14, 14)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jB2)
                    .addComponent(jB3)
                    .addComponent(jBSubtracao)
                    .addComponent(jB1, javax.swing.GroupLayout.PREFERRED_SIZE, 28, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jBMultiplicacao1, javax.swing.GroupLayout.PREFERRED_SIZE, 32, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(11, 11, 11)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jB0, javax.swing.GroupLayout.PREFERRED_SIZE, 30, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jBPonto, javax.swing.GroupLayout.PREFERRED_SIZE, 30, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jBIgual, javax.swing.GroupLayout.PREFERRED_SIZE, 31, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jBAdicao, javax.swing.GroupLayout.PREFERRED_SIZE, 31, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jBPotencia, javax.swing.GroupLayout.PREFERRED_SIZE, 31, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(21, 21, 21))
        );

        jPanel1Layout.linkSize(javax.swing.SwingConstants.VERTICAL, new java.awt.Component[] {jB0, jB1, jB2, jB3, jB4, jB5, jB6, jB7, jB8, jB9, jBAdicao, jBBackSpace, jBCe, jBClr, jBDivisao, jBIgual, jBMultiplicacao, jBPonto, jBSubtracao, jBSubtracaoAdicao});

        jMenu1.setText("Sair");
        jMenu1.addMouseListener(new java.awt.event.MouseAdapter() {
            public void mouseClicked(java.awt.event.MouseEvent evt) {
                jMenu1MouseClicked(evt);
            }
        });
        jMenuBar1.add(jMenu1);

        setJMenuBar(jMenuBar1);

        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()
                .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(layout.createSequentialGroup()
                .addGap(22, 22, 22)
                .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );

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

    private void jTVisorActionPerformed(java.awt.event.ActionEvent evt) {                                        
        // TODO add your handling code here:
    }                                       

    private void jB0ActionPerformed(java.awt.event.ActionEvent evt) {                                    
        numeroDigitado("0");
        
    }                                   

    private void jB8ActionPerformed(java.awt.event.ActionEvent evt) {                                    
       numeroDigitado("8");
    }                                   

    private void jB2ActionPerformed(java.awt.event.ActionEvent evt) {                                    
        numeroDigitado("2");
    }

    private void numeroDigitado ( String numero) {
        temp = jTVisor.getText();
        numeroAntes = temp;
        temp = temp + numero;
        jTVisor.setText(temp);
    }                                   

    private void jB7ActionPerformed(java.awt.event.ActionEvent evt) {                                    
        numeroDigitado("7");
    }                                   

    private void jB9ActionPerformed(java.awt.event.ActionEvent evt) {                                    
        numeroDigitado("9");
    }                                   

    private void jB4ActionPerformed(java.awt.event.ActionEvent evt) {                                    
        numeroDigitado("4");
    }                                   

    private void jB5ActionPerformed(java.awt.event.ActionEvent evt) {                                    
        numeroDigitado("5");
    }                                   

    private void jB6ActionPerformed(java.awt.event.ActionEvent evt) {                                    
        numeroDigitado("6");
    }                                   

    private void jB1ActionPerformed(java.awt.event.ActionEvent evt) {                                    
        numeroDigitado("1");
    }                                   

    private void jB3ActionPerformed(java.awt.event.ActionEvent evt) {                                    
        numeroDigitado("3");
    }                                   

    private void jBPontoActionPerformed(java.awt.event.ActionEvent evt) {                                        
        numeroDigitado(".");
    }                                       

    private void jBAdicaoActionPerformed(java.awt.event.ActionEvent evt) {                                         
        escolheOperacao('+');
    }                                        

    private void jBClrActionPerformed(java.awt.event.ActionEvent evt) {                                      
        num1 = 0.0;
        num2 = 0.0;
        jTVisor.setText("");


    }                                     

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

        num2 = Double.parseDouble(jTVisor.getText());

    switch(operacao){
        
        case '+':
            resultado = num1 + num2;
            break;

        case '-':
            resultado = num1 - num2;
            break;

        case '*':
            resultado = num1 * num2;
            break;

        case '/':
            resultado = num1 / num2;
            break;

        case '1':
            resultado = Math.pow(jTVisor.getText());
            break;

        case '2':
            resultado = Math.sqrt(jTVisor.getText());
            break;
        case '3':
            for(cont = 1; cont<=10; cont++){
                    jTVisor.setText(result = temp + " x " + cont + " = " + (temp * cont)"\n" ;
            }
            
            break;
        
        }
            jTVisor.setText(String.valueOf(resultado));

    }                                       

    private void jBSubtracaoActionPerformed(java.awt.event.ActionEvent evt) {                                            
        escolheOperacao('-');
    }                                           

    private void jBMultiplicacaoActionPerformed(java.awt.event.ActionEvent evt) {                                                
        escolheOperacao('*');
    }                                               

    private void jBDivisaoActionPerformed(java.awt.event.ActionEvent evt) {                                          
        escolheOperacao('/');
    }                                         

    private void jBDivisao1ActionPerformed(java.awt.event.ActionEvent evt) {                                           
        // TODO add your handling code here:
    }                                          

    private void jBMultiplicacao1ActionPerformed(java.awt.event.ActionEvent evt) {                                                 
         escolheOperacao('2');
    }                                                

    private void jBSubtracao1ActionPerformed(java.awt.event.ActionEvent evt) {                                             
        // TODO add your handling code here:
    }                                            

    private void jBPotenciaActionPerformed(java.awt.event.ActionEvent evt) {                                           
    escolheOperacao('1');
    }                                          

    private void jBCeActionPerformed(java.awt.event.ActionEvent evt) {                                     
        num2 =0.0;
        jTVisor.setText(String.valueOf(num1));

    }                                    

    private void jBBackSpaceActionPerformed(java.awt.event.ActionEvent evt) {                                            
        temp = numeroAntes;
        jTVisor.setText(temp);
    }                                           

    private void jMenu1MouseClicked(java.awt.event.MouseEvent evt) {                                    
        System.exit(0);
    }                                   

    /**
    * @param args the command line arguments
    */
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new JFCalc().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify                     
    private javax.swing.JButton jB0;
    private javax.swing.JButton jB1;
    private javax.swing.JButton jB2;
    private javax.swing.JButton jB3;
    private javax.swing.JButton jB4;
    private javax.swing.JButton jB5;
    private javax.swing.JButton jB6;
    private javax.swing.JButton jB7;
    private javax.swing.JButton jB8;
    private javax.swing.JButton jB9;
    private javax.swing.JButton jBAdicao;
    private javax.swing.JButton jBBackSpace;
    private javax.swing.JButton jBCe;
    private javax.swing.JButton jBClr;
    private javax.swing.JButton jBDivisao;
    private javax.swing.JButton jBDivisao1;
    private javax.swing.JButton jBIgual;
    private javax.swing.JButton jBMultiplicacao;
    private javax.swing.JButton jBMultiplicacao1;
    private javax.swing.JButton jBPonto;
    private javax.swing.JButton jBPotencia;
    private javax.swing.JButton jBSubtracao;
    private javax.swing.JButton jBSubtracao1;
    private javax.swing.JButton jBSubtracaoAdicao;
    private javax.swing.JButton jBSubtracaoAdicao1;
    private javax.swing.JMenu jMenu1;
    private javax.swing.JMenuBar jMenuBar1;
    private javax.swing.JPanel jPanel1;
    private javax.swing.JTextField jTVisor;
    // End of variables declaration                   


}
Alura Desenvolvimento Back-End Java Sua Carreira em desenvolvimento back-end Java: dos fundamentos à arquitetura de sistemas...

9 Respostas

Marlon_Meneses
Marlon_Meneses

use o jformatedtext

fabiobufalari
fabiobufalari

com jformated tem como exibir uma mensagem ?

Marlon_Meneses
Marlon_Meneses

creio que sim

nel
nel

Oi!

Não aceitar letras seria aceitar somente números? Ou no seu caso, pode aceitar números, caracteres e etc, menos letras?
Abraços.

fabiobufalari
fabiobufalari

somente numeros

nel
nel

Tem algo chamado Regex. Quando puder, dê uma pesquisada sobre o assunto, é muito útil em várias situações.

String s = "105bc5~"; boolean result = s.matches("[0-9]+");

O result será false, pois não há somente números. Caso houvesse, seria true.
O que fiz foi simplesmente perguntar se o conteúdo da String contém exclusivamente um ou mais caracteres 0, 1, 2…9.

Podes ler sobre Pattern também :slight_smile:

Abraços.

A
alissonpedrina 
public class JFCalc {  
  
     
   public static void main(String... args) throws Exception{
	   String str = "1234";
	   String strNum = "AAAA";
	   
	   Pattern pattern = Pattern.compile("[0-9]");
	   Matcher matcher = pattern.matcher(str);
	   
	   if (!matcher.find()){
		   throw new Exception();
	   }else{
		   System.out.println("OK!!");
	   }
	   
   }
}
nel
nel
alissonpedrina:
public class JFCalc {  
  
     
   public static void main(String... args) throws Exception{
	   String str = "1234";
	   String strNum = "AAAA";
	   
	   Pattern pattern = Pattern.compile("[0-9]");
	   Matcher matcher = pattern.matcher(str);
	   
	   if (!matcher.find()){
		   throw new Exception();
	   }else{
		   System.out.println("OK!!");
	   }
	   
   }
}

Alisson, perceba que faltou o simbolo '+' ao fim da sua expressão regular conforme eu fiz logo acima :)
Sem o mais, ele não testa toda a String.

X+ X, one or more times.

Ou seja, aparece uma única vez ou mais :)
Abraços.

ViniGodoy
ViniGodoy

Veja os seguintes links.

Aqui mostra como fazer o teclado de calculadora ser acionado quando números são pressionados:

Aqui mostra como fazer o JTextField só aceitar números:
http://www.guj.com.br/articles/29

Criado 4 de julho de 2011
Ultima resposta 4 de jul. de 2011
Respostas 9
Participantes 5

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