すべてのグラフィック要素を保持するGUIFrameと呼ばれる 2 つのクラスとsqueakと呼ばれるスレッド クラスがあります。GUIFrameには 2 つのグラフィック要素があり、最初のボタンはクリックするとスレッドを起動します。
futures.put(1, pool.submit(new squeak("SqueakyThread",this.jTextArea1)));
2 つ目は、jTextArea1という変数を持つjavax.swing.JTextAreaです。
前述の 2 番目のクラスは、 squeak (Runnable を実装)と呼ばれるスレッド クラスであり、 while(true)ループを収容します。このクラスが行うのは、1 から 10 までの乱数を生成し、その数値をGUIFrameクラスのjTextArea1に出力することだけです。
質問:これは、Java で GUI 要素を更新する正しい正式な方法ですか?
この質問が多く寄せられていることは承知していますが、さまざまな回答が寄せられているため、これが私自身や他の人にとって簡単なテンプレートになることを願っています.
GUIFrame.java
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
public class GUIFrame extends javax.swing.JFrame {
public GUIFrame() {
this.pool = Executors.newCachedThreadPool();
initComponents();
}
private ExecutorService pool;
private Map<Integer, Future<?>> futures = new HashMap<>();
/**
* 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() {
jButton1 = new javax.swing.JButton();
jScrollPane2 = new javax.swing.JScrollPane();
jTextArea1 = new javax.swing.JTextArea();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jButton1.setText("Start");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
jTextArea1.setEditable(false);
jTextArea1.setColumns(20);
jTextArea1.setRows(5);
jScrollPane2.setViewportView(jTextArea1);
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(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, 468, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(jButton1, javax.swing.GroupLayout.DEFAULT_SIZE, 188, Short.MAX_VALUE)
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addGap(0, 0, Short.MAX_VALUE)
.addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 96, javax.swing.GroupLayout.PREFERRED_SIZE))
.addComponent(jScrollPane2, javax.swing.GroupLayout.DEFAULT_SIZE, 444, Short.MAX_VALUE))
.addContainerGap())
);
pack();
}// </editor-fold>
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
futures.put(1, pool.submit(new squeak("SqueakyThread",this.jTextArea1)));
}
/**
* @param args the command line arguments
*/
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(GUIFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(GUIFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(GUIFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(GUIFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
new GUIFrame().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
private javax.swing.JScrollPane jScrollPane2;
private javax.swing.JTextArea jTextArea1;
// End of variables declaration
}
squeak.java
import java.util.Random;
import java.util.concurrent.TimeUnit;
import javax.swing.SwingUtilities;
public class squeak implements Runnable {
private String Type = "";
private javax.swing.JTextArea MW;
squeak (String type, javax.swing.JTextArea MW)
{
this.Type = type;
this.MW = MW;
}
@Override
public void run ()
{
while(true)
{
UpdateGUI(RandomNumber()+"\r\n");
try {
TimeUnit.SECONDS.sleep(10);
} catch (InterruptedException e)
{
UpdateGUI("Thread is now Exiting!\r\n");
//Return cause program to exit the while(true) loop and end
return;
}
}
}
private int RandomNumber(){
Random r = new Random();
int num = r.nextInt(10-1) + 1;
return num;
}
private void UpdateGUI(final String foo) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
// Here, we can safely update the GUI
// because we'll be called from the
// event dispatch thread
MW.append(foo);
}
});
}
}