Threads in Java

Question

This is the first time I’ve been working with Threads. I created two threads, one to run the report generator (iReport) and one to operate a progress bar (Jprogressbar). However, even using flag, Thread is not terminated (state - TERMINATED), that is, it remains in the RUNNABLE state. See:

package util;

import java.io.InputStream;
import java.sql.ResultSet;
import java.util.Map;
import java.util.concurrent.atomic.AtomicBoolean;
import javax.swing.JProgressBar;
import visao.TelaRelatorioCadastral;

/**
 *
 * @author JFSJUNIOR
 */
public class ControlaThread{
    private Thread threadBarraProgresso;
    private Thread threadEmissaoRelatorio;
    private final AtomicBoolean rodando = new AtomicBoolean(false);
    private JProgressBar progresso;
    private InputStream fluxo;
    private ResultSet dados;
    private TelaRelatorioCadastral tela;
    private Map param;

    public ControlaThread(JProgressBar barraProgresso, 
            InputStream caminho, ResultSet resultados, 
            TelaRelatorioCadastral telaCad, Map paramentros){
        progresso = barraProgresso;
        fluxo = caminho;
        dados = resultados;
        tela = telaCad;
        param = paramentros;
    }

    public void start(){
        threadBarraProgresso = new Thread(new Runnable(){
            @Override
            public void run() {
                rodando.set(true);
                while(progresso.getValue() < 100 && rodando.get()){
                    try {
                        Thread.sleep(100);
                        progresso.setValue(progresso.getValue() + 10);
                    } catch (InterruptedException iex) {
                        System.out.println("ERRO: " + iex.getMessage());
                    }
                }
            }
        });

        threadEmissaoRelatorio= new Thread(new Runnable(){
            @Override
            public void run() {
                if(rodando.get())
                    GeradorDeRelatorio.gerarRelatorio(fluxo, param, dados, tela);
            }
        });

        threadBarraProgresso.start();
        threadEmissaoRelatorio.start();
    }

    public void stop(){
        rodando.set(false);
        System.out.println("Finalizado");
    }
}

Everything works, but the screen that calls this class always comes set with the last option chosen (in a Jcombobox) and the previous bar is completed (100%). How to stop Threads without using the deprecated stop() because the flags are not working? Where am I missing?

Additional information

1 - Checking the name of threads in the stop method:

public void stop(){
        rodando.set(false);
        System.out.println("Finalizado");
        System.out.println("NomeThreadBE: " + threadBarraProgresso.getName());
        System.out.println("NomeThreadER: " + threadEmissaoRelatorio.getName());
}

generates:

run:
Finalizado
NomeThreadBE: Thread-2
NomeThreadER: Thread-3

Here the button method:

private void btnGerarActionPerformed(java.awt.event.ActionEvent evt) {                                         
        if(cbxItemRelatorio.getSelectedIndex() != OPCAO_INVALIDA){
            int opcao =  cbxItemRelatorio.getSelectedIndex();
            InputStream stream;
            ResultSet resultSet;
            Connection conexao;
            ControlaThread controle;
            parametros.put("logo", "/img/");
            parametros.put("SUBREPORT_DIR", "/relatorio/");
            terminado = false;

            try{
                switch(opcao){
                    case 1:
                        stream = getClass().getResourceAsStream(
                                "/relatorio/rc_plano_conta.jasper");
                        resultSet = dao.ContaContabil.retornarPlanoContas();
                        conexao = null;

                        construirRelatorio(stream, resultSet, conexao, this);
                        break;
                    case 5:
                        stream = getClass().getResourceAsStream(
                                "/relatorio/rc_cliente.jasper");
                        resultSet = null;
                        conexao = ConectaBancoDeDados.getConexao();

                        construirRelatorio(stream, resultSet, conexao, this);
                        break;
                    case 9:
                        stream = getClass().getResourceAsStream(
                                "/relatorio/rc_raca.jasper");
                        resultSet = dao.Raca.retornarRelatorioRaca();
                        conexao = null;


                        controle = new ControlaThread(barraProgresso, stream, resultSet, this, parametros);
                        controle.start();
                        controle.stop();
                        break;
                }
            }catch(SQLException sqle){
                System.out.println("ERRO: " + sqle.getMessage());
                JOptionPane.showMessageDialog(this, "Relatório não foi gerado. " 
                    + sqle.getMessage());
            }
        }else{
             JOptionPane.showMessageDialog(this, "Opção inválida!");
        }
    }

Note: As I only built the race report, I am using case 9 for the tests.

===========================================================================

Updated code

Case 9 of the button:

case 9:
    stream = getClass().getResourceAsStream(
            "/relatorio/rc_raca.jasper");
    resultSet = dao.Raca.retornarRelatorioRaca();
    conexao = null;
    construirRelatorio(stream, resultSet, conexao, this);
    break;

and the previous class code I transferred to the build method with some modifications:

private void construirRelatorio(InputStream caminho, ResultSet resultados, 
            Connection conexao, TelaRelatorioCadastral telaCad) 
            throws SQLException{
        final int SONECA = 500;
        final int PERIODO = 10;

        thredRelatorio = new Thread(new Runnable(){
            @Override
            public void run(){
                rodando.set(true);
                if(rodando.get()){
                    if(resultados != null){
                        GeradorDeRelatorio.gerarRelatorio(caminho, parametros,
                            resultados);
                    }
                    if(conexao != null)
                        GeradorDeRelatorio.gerarRelatorio(caminho, parametros,
                            conexao);
                }
                stop();
            }
        });

        threadBarraProgresso = new Thread(new Runnable(){
            @Override
            public void run(){
                rodando.set(true);
                while(barraProgresso.getValue() < 100 && rodando.get()){
                    try{
                        Thread.sleep(SONECA);
                        barraProgresso.setValue(barraProgresso.getValue() 
                                + PERIODO);

                        descreverProgresso(barraProgresso.getValue());

                    }catch(InterruptedException iex){
                        System.out.println("ERRO: " + iex.getMessage());
                        break;
                    }
                }
                thredRelatorio.start();
                telaCadastro.dispose();
                reconfigurarCampos();
            }
        });
        threadBarraProgresso.start();
    }

The Stop method:

private void stop(){
        rodando.set(false);

        System.out.println("Finalizado");
        System.out.println("NomeThreadBE: " + threadBarraProgresso.getName());
        System.out.println("NomeThreadER: " + thredRelatorio.getName());

        System.out.println("StatusBE: " + threadBarraProgresso.getState());
        System.out.println("StatusER: " + thredRelatorio.getState());
    }

And the method that describes progress:

private void descreverProgresso(int progresso){
        if(progresso < 25)
            lblStatus.setText("Reunindo dados...");
        if(progresso > 25 && progresso < 50)
            lblStatus.setText("Obtendo parâmetros...");
        if(progresso > 50 && progresso < 100)
            lblStatus.setText("Construindo o relatório...");
        if(progresso == 100)
            lblStatus.setText("Concluído!");
    }

I put the report thread start() method at the end (after while) of the progress bar thread to ensure that the report thread will only be called when the progress bar thread has TERMINATED status. I tried this using John, but it is difficult to hit the threads' 'time' (hence I would have to put the value of NAP very low), since in certain situations the report is generated with the progress bar at 20%, 30%, hence the bar thread enters WAITING or TIMED-WAITING. I ran the test generating the report without calling the method JasperViewer.viewReport(jasperPrint, false); to see if this is what kept the thread in RUNNABLE, but to no avail.

Thanks in advance.

Answer 1

In my view it’s not that she’s finishing, it’s that you’re not having time to see her finish, even if you seven running it to false, it’s not automatic, the thread is already there inside the while running, will do the whole process and at the same time comes your print indicating that it is running, if you really want to see that the state has ended, after setting the flag you can give one . Join() in the bar thread you will see that in fact it will end,

public void stop(){
        rodando.set(false);
        threadBarraProgresso.join();
        System.out.println("Finalizado");
        System.out.println("NomeThreadBE: " + threadBarraProgresso.getState());
}

the fact that the bar already appears complete was as I explained, with a thread of 100 milliseconds and a bar of percentage 100 in 1 second it already complete, try to change it (increase the thread size.Leep for example) that you will see it going up,

while(progresso.getValue() < 100 && rodando.get()){
                    try {
                        Thread.sleep(1000);
                        progresso.setValue(progresso.getValue() + 10);
                    } catch (InterruptedException iex) {
                        System.out.println("ERRO: " + iex.getMessage());
                    }
                }

the problem of the already selected combobox ta appear not in your code, it is something else totally out of that you posted ai