在单击之前无法加载从 JFreeChart 加载图表的线程

Question

我认为我做的一切都是对的。我想要的只是在加载组件的主线程和 window 完成后加载包含图表的线程。但它没有用。我必须以某种方式单击 jPanel1（将加载图表的面板）并加载图表。任何帮助，将不胜感激。我尝试过的：

将线程更改为 SwingWorker
正在将主题更改为 invokeLater

public LaporanPenjualan() {
    initComponents();
    createFrame1();
}
    
private void createFrame1() {
    SwingWorker thread = new SwingWorker() {
        @Override
        protected Boolean doInBackground() throws Exception {
            JLabel loading = new JLabel("Loading, please wait",SwingConstants.CENTER);
            loading.setSize(500,500);
            loading.setAlignmentY(250);
            jPanel1.add(loading);
            final DefaultCategoryDataset dataset = new DefaultCategoryDataset();
            dataset.addValue(34.0, "Penjualan/produk", "Kue Enak");
            dataset.addValue(23.0, "Penjualan/produk", "Kue Enggak Enak");
            dataset.addValue(54.0, "Penjualan/produk", "Kue Sultan");
            final JFreeChart chart = ChartFactory.createBarChart(
                    "", 
                    "Produk",
                    "Penjualan",
                    dataset,
                    PlotOrientation.VERTICAL,
                    true,
                    true,
                    false
                );
            final ChartPanel chartPanel = new ChartPanel(chart);
            chartPanel.setSize(500,500);
            chartPanel.setPreferredSize(new Dimension(300, 300));
            jPanel1.removeAll();
            jPanel1.add(chartPanel);
            chartPanel.setVisible(true);
            return true;
        }
    };                 
    thread.execute();
}

Answer 1

Swing 是单线程的，不是线程安全的。这意味着您不应该在事件调度线程的上下文中执行任何长运行或阻塞操作，并且您不应该修改 UI 的状态或 UI 的任何状态依赖于，来自 EDT 的上下文。

所以，话虽如此，您 createFrame1 可能看起来更像...

private void createFrame1() {
    JLabel loading = new JLabel("Loading, please wait", SwingConstants.CENTER);
    loading.setSize(500, 500);
    loading.setAlignmentY(250);
    jPanel1.add(loading);
    jPanel1.revalidate();
    jPanel1.repaint();

    SwingWorker<DefaultCategoryDataset, Void> thread;
    thread = new SwingWorker<>() {

        @Override
        protected DefaultCategoryDataset doInBackground() throws Exception {
            final DefaultCategoryDataset dataset = new DefaultCategoryDataset();
            dataset.addValue(34.0, "Penjualan/produk", "Kue Enak");
            dataset.addValue(23.0, "Penjualan/produk", "Kue Enggak Enak");
            dataset.addValue(54.0, "Penjualan/produk", "Kue Sultan");
            return dataset;
        }

        @Override
        protected void done() {
            try {
                DefaultCategoryDataset dataset = get();

                final JFreeChart chart = ChartFactory.createBarChart(
                        "",
                        "Produk",
                        "Penjualan",
                        dataset,
                        PlotOrientation.VERTICAL,
                        true,
                        true,
                        false
                );
                final ChartPanel chartPanel = new ChartPanel(chart);
                jPanel1.removeAll();
                jPanel1.add(chartPanel);
                chartPanel.setVisible(true);
            } catch (InterruptedException ex) {
                Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
            } catch (ExecutionException ex) {
                Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
            }
        }

    };
    thread.execute();
}

或者，如果加载数据需要时间，您可以发布每个数据点...

public class DataPoint {

    private double value;
    private Comparable rowKey;
    private Comparable columnKey;

    public DataPoint(double value, Comparable rowKey, Comparable columnKey) {
        this.value = value;
        this.rowKey = rowKey;
        this.columnKey = columnKey;
    }

    public double getValue() {
        return value;
    }

    public Comparable getRowKey() {
        return rowKey;
    }

    public Comparable getColumnKey() {
        return columnKey;
    }
}

private void createFrame1() {
    SwingWorker<Void, DataPoint> thread;
    DefaultCategoryDataset dataSet = new DefaultCategoryDataset();
    final JFreeChart chart = ChartFactory.createBarChart(
            "",
            "Produk",
            "Penjualan",
            dataSet,
            PlotOrientation.VERTICAL,
            true,
            true,
            false
    );
    final ChartPanel chartPanel = new ChartPanel(chart);
    jPanel1.add(chartPanel);

    thread = new SwingWorker<>() {

        @Override
        protected Void doInBackground() throws Exception {
            publish(new DataPoint(34.0, "Penjualan/produk", "Kue Enak"));
            publish(new DataPoint(23.0, "Penjualan/produk", "Kue Enggak Enak"));
            publish(new DataPoint(54.0, "Penjualan/produk", "Kue Sultan"));
        }

        @Override
        protected void process(List<DataPoint> chunks) {
            for (DataPoint dp : chunks) {
                dataSet.addValue(dp.getValue(), dp.getRowKey(), dp.getColumnKey());
            }
        }
    };
    thread.execute();
}

可运行示例...

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingWorker;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.data.category.DefaultCategoryDataset;

public class Test {

    public static void main(String[] args) {
        new Test();
    }

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame frame = new JFrame();
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        public TestPane() {
            setLayout(new BorderLayout());
            DefaultCategoryDataset dataSet = new DefaultCategoryDataset();
            final JFreeChart chart = ChartFactory.createBarChart(
                    "",
                    "Produk",
                    "Penjualan",
                    dataSet,
                    PlotOrientation.VERTICAL,
                    true,
                    true,
                    false
            );
            final ChartPanel chartPanel = new ChartPanel(chart);
            add(chartPanel);

            ChartWorker worker = new ChartWorker(dataSet);
            worker.execute();
        }
    }

    public class ChartWorker extends SwingWorker<Void, ChartWorker.DataPoint> {

        public class DataPoint {

            private double value;
            private Comparable rowKey;
            private Comparable columnKey;

            public DataPoint(double value, Comparable rowKey, Comparable columnKey) {
                this.value = value;
                this.rowKey = rowKey;
                this.columnKey = columnKey;
            }

            public double getValue() {
                return value;
            }

            public Comparable getRowKey() {
                return rowKey;
            }

            public Comparable getColumnKey() {
                return columnKey;
            }
        }

        private DefaultCategoryDataset dataSet;

        public ChartWorker(DefaultCategoryDataset dataSet) {
            this.dataSet = dataSet;
        }

        @Override
        protected Void doInBackground() throws Exception {
            // The sleeps here are just for demonstration, 
            // you don't need them
            Thread.sleep(1000);
            publish(new DataPoint(34.0, "Penjualan/produk", "Kue Enak"));
            Thread.sleep(1000);
            publish(new DataPoint(23.0, "Penjualan/produk", "Kue Enggak Enak"));
            Thread.sleep(1000);
            publish(new DataPoint(54.0, "Penjualan/produk", "Kue Sultan"));
            return null;
        }

        @Override
        protected void process(List<DataPoint> chunks) {
            for (DataPoint dp : chunks) {
                dataSet.addValue(dp.getValue(), dp.getRowKey(), dp.getColumnKey());
            }
        }
    }
}

等待事情完成...

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.util.concurrent.ExecutionException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingWorker;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.data.category.DefaultCategoryDataset;

public class Test {

    public static void main(String[] args) {
        new Test();
    }

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame frame = new JFrame();
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        public TestPane() {
            setLayout(new BorderLayout());

            add(new JLabel("Loading stuff", JLabel.CENTER));

            ChartWorker worker = new ChartWorker();
            worker.addPropertyChangeListener(new PropertyChangeListener() {
                @Override
                public void propertyChange(PropertyChangeEvent evt) {
                    if ("state".equals(evt.getPropertyName())) {
                        if (worker.getState() == SwingWorker.StateValue.DONE) {
                            try {
                                DefaultCategoryDataset dataSet = worker.get();
                                setDataSet(dataSet);
                            } catch (InterruptedException ex) {
                                add(new JLabel("Loading fauked", JLabel.CENTER));
                                Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
                            } catch (ExecutionException ex) {
                                add(new JLabel("Loading fauked", JLabel.CENTER));
                                Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
                            }
                        }
                    }
                }
            });
            worker.execute();
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(400, 400);
        }

        protected void setDataSet(DefaultCategoryDataset dataSet) {
            final JFreeChart chart = ChartFactory.createBarChart(
                    "",
                    "Produk",
                    "Penjualan",
                    dataSet,
                    PlotOrientation.VERTICAL,
                    true,
                    true,
                    false
            );
            final ChartPanel chartPanel = new ChartPanel(chart);
            removeAll();
            add(chartPanel);
            revalidate();
            repaint();
        }

    }

    public class ChartWorker extends SwingWorker<DefaultCategoryDataset, Void> {

        public ChartWorker() {
        }

        @Override
        protected DefaultCategoryDataset doInBackground() throws Exception {
            DefaultCategoryDataset dataSet = new DefaultCategoryDataset();
            dataSet.addValue(34.0, "Penjualan/produk", "Kue Enak");
            dataSet.addValue(23.0, "Penjualan/produk", "Kue Enggak Enak");
            dataSet.addValue(54.0, "Penjualan/produk", "Kue Sultan");

            // Again, you don't need this
            Thread.sleep(5000);

            return dataSet;
        }
    }
}

在单击之前无法加载从 JFreeChart 加载图表的线程

Cannot load a thread that loads chart from JFreeChart until clicked

java

swing

multithreading

可运行示例...

等待事情完成...