How to update text in jTextArea?

Asked

Viewed 264 times

0

How do I update the jTextArea? I try to update it with the click of a button, but I can’t. I want to add new texts along with the previous ones, but so far without success. I performed the implementation in the terminal (System.out) and it worked normally, the problem is to make the text appear in the jTextArea. What to do?

public class Tela extends javax.swing.JFrame {
    /**
     * Creates new form Tela
     */
    public Tela() {
        initComponents();
    }
    static int option;
    static int acao,cont=0;
    static String conteudo,str;

    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jLabel2 = new javax.swing.JLabel();
        jLabel1 = new javax.swing.JLabel();
        lblValor = new javax.swing.JTextField();
        jButton2 = new javax.swing.JButton();
        jScrollPane2 = new javax.swing.JScrollPane();
        text = new javax.swing.JTextArea();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        setBackground(new java.awt.Color(1, 1, 1));
        setResizable(false);

        jLabel2.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
        jLabel2.setIcon(new javax.swing.ImageIcon(getClass().getResource("/images/graphics-1658177_960_720.png"))); // NOI18N

        jLabel1.setForeground(new java.awt.Color(5, 0, 0));
        jLabel1.setText("O que deseja fazer(digite uma opção):)");
        jLabel1.setToolTipText("");

        lblValor.setForeground(new java.awt.Color(1, 1, 1));
        lblValor.setHorizontalAlignment(javax.swing.JTextField.CENTER);
        lblValor.setToolTipText("");

        jButton2.setText("Confirmar");
        jButton2.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton2ActionPerformed(evt);
            }
        });

        jScrollPane2.setHorizontalScrollBarPolicy(javax.swing.ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
        jScrollPane2.setVerticalScrollBarPolicy(javax.swing.ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
        jScrollPane2.setAutoscrolls(true);

        text.setEditable(false);
        text.setColumns(20);
        text.setRows(5);
        jScrollPane2.setViewportView(text);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createSequentialGroup()
                        .addContainerGap()
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(jLabel2, javax.swing.GroupLayout.DEFAULT_SIZE, 712, Short.MAX_VALUE)
                            .addGroup(layout.createSequentialGroup()
                                .addComponent(jLabel1)
                                .addGap(0, 0, Short.MAX_VALUE))))
                    .addGroup(layout.createSequentialGroup()
                        .addGap(85, 85, 85)
                        .addComponent(lblValor, javax.swing.GroupLayout.PREFERRED_SIZE, 211, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(95, 95, 95)
                        .addComponent(jButton2, javax.swing.GroupLayout.PREFERRED_SIZE, 192, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(0, 0, Short.MAX_VALUE))
                    .addGroup(layout.createSequentialGroup()
                        .addContainerGap()
                        .addComponent(jScrollPane2)))
                .addContainerGap())
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addComponent(jLabel2, javax.swing.GroupLayout.PREFERRED_SIZE, 60, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, 205, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(jLabel1)
                .addGap(30, 30, 30)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                    .addComponent(jButton2, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(lblValor, javax.swing.GroupLayout.DEFAULT_SIZE, 44, Short.MAX_VALUE))
                .addGap(0, 29, Short.MAX_VALUE))
        );

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

    private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        option = Integer.parseInt(lblValor.getText());
        cont+=1;
        historia(option,cont);
    }                                        

    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(Tela.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(Tela.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(Tela.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(Tela.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>
       /* Create and display the form */
       Tela t = new Tela();
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                t.setVisible(true);
                t.text.setText("Seja bem-vindo ao jogo que as suas decisões podem  "
                + "matar ou salvar alguém...\nSó depende de você! Boa sorte!"
             + "Você está pronto?\n 1 - SIM\n 2 - NÃO\n\n");   
            }
        });    
    }
    public static void historia(int decisao,int cont){
        Textos text = new Textos();
        Tela t = new Tela();
        if(cont == 1){
            switch(decisao){
                case 1:
                    str = "Você tomou essa decisão... A partir de agora tudo está por sua\n"
             + "conta em risco... Salve-se... A aventura começa agora...\n";
                    t.text.append(str);//não atualiza o texto
                    System.out.println(t.text.getText());
            }
        }
    }

    // Variables declaration - do not modify                     
    private javax.swing.JButton jButton2;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JScrollPane jScrollPane2;
    private javax.swing.JTextField lblValor;
    private javax.swing.JTextArea text;
    // End of variables declaration                   
}
java swing jtextarea

  • Your comfort is not executable. To help you, provide a [mcve], so it will be possible to execute the code and check the problem.

  • https://answall.com/questions/41571/como-update-um-jtextarea-informa%C3%A7%C3%B5es-de-jcheckboxes - this does not help?

  • Without a [mcve] It is difficult to help, and sending us to visit another link does not help either. Visit the link and try to provide an example that anyone can run, if it doesn’t get complicated to help you.

  • I have tried such article, but without success. I could not implement nor understand the method of posting.

  • 1

    How we’ll help you if we can’t even execute the code?

  • 1

    The code is not yet executable. Tip to create an executable example: 1) create a new project and isolate only the problematic code by removing dependencies; 2) test the code to see if it is working.

  • And now, the code can be executed?

  • See my previous comment.

  • Okay! Thank you, I will redo the code and reset it again. Thanks in advance.

Show 4 more comments

1 answer

0


Well, I did the programming from scratch and discovered the problem myself. I hope my question and answer can help others with similar questions. The problem lies in the following code snippet:

public static void historia(int decisao,int cont){
    Textos text = new Textos();
    Tela t = new Tela();
    if(cont == 1){
        switch(decisao){
            case 1:
                str = "Você tomou essa decisão... A partir de agora tudo está por sua\n"
         + "conta em risco... Salve-se... A aventura começa agora...\n";
                t.text.append(str);//não atualiza o texto
                System.out.println(t.text.getText());
        }
    }
}

The big question is that by creating the Tela t = new Tela() I’m creating another instance for creating another screen in the interface. So the correction was as follows:

public static void historia(int decisao,int cont){
Textos text = new Textos();
if(cont == 1){
    switch(decisao){
        case 1:
            str = "Você tomou essa decisão...";
            this.text.append(str);//atualiza o texto
            System.out.println(t.text.getText());
    }
}

}

It was a matter of failure in POO. I thank everyone who tried to help me and I hope to help others with the same doubt.

Browser other questions tagged java swing jtextarea

You are not signed in. Login or sign up in order to post.