メモリを消費するスレッドを制御する方法

Question

スレッドを使用してGUIテキストエディタを構築しています。このエディタでは、1つのスレッドはテキスト領域の文字数と文字数をカウントし、まだ実装されていません）。

メインウィンドウGUI

import java.util.Calendar; 
import java.util.Locale; 

public class MainWindow extends javax.swing.JFrame { 
    /** 
    * Creates new form MainWindow 
    */ 

    private long initial,last; 
    public MainWindow() { 
     initComponents(); 

     Operation op = new Operation(this); 
     // new FileOperation(op, "demo.txt"); 
     new Count(op); 

    } 


    public void saveFile(){ 

    } 

    public void countUpdate(String wordCount){ 

     System.out.println(wordCount); 
     counting.setText(wordCount); 
    } 

    public long getTime(){ return last-initial;} 

    public String getInput(){ return textfield.getText();} 

    /** 
    * 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">//GEN-BEGIN:initComponents 
    private void initComponents() { 

     jScrollPane1 = new javax.swing.JScrollPane(); 
     textfield = new javax.swing.JTextArea(); 
     save = new javax.swing.JLabel(); 
     counting = new javax.swing.JLabel(); 

     setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE); 

     textfield.setColumns(20); 
     textfield.setRows(5); 
     textfield.addKeyListener(new java.awt.event.KeyAdapter() { 
      public void keyPressed(java.awt.event.KeyEvent evt) { 
       textfieldKeyPressed(evt); 
      } 
      public void keyReleased(java.awt.event.KeyEvent evt) { 
       textfieldKeyReleased(evt); 
      } 
     }); 
     jScrollPane1.setViewportView(textfield); 

     save.setText(" "); 

     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() 
       .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false) 
        .addGroup(layout.createSequentialGroup() 
         .addComponent(save, javax.swing.GroupLayout.PREFERRED_SIZE, 75, javax.swing.GroupLayout.PREFERRED_SIZE) 
         .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE) 
         .addComponent(counting, javax.swing.GroupLayout.PREFERRED_SIZE, 103, javax.swing.GroupLayout.PREFERRED_SIZE)) 
        .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 370, javax.swing.GroupLayout.PREFERRED_SIZE)) 
       .addContainerGap(18, Short.MAX_VALUE)) 
     ); 
     layout.setVerticalGroup(
      layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) 
      .addGroup(layout.createSequentialGroup() 
       .addGap(26, 26, 26) 
       .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 240, javax.swing.GroupLayout.PREFERRED_SIZE) 
       .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED) 
       .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) 
        .addGroup(layout.createSequentialGroup() 
         .addComponent(save) 
         .addGap(0, 0, Short.MAX_VALUE)) 
        .addComponent(counting, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)) 
       .addContainerGap()) 
     ); 

     pack(); 
    }// </editor-fold>//GEN-END:initComponents 

    private void textfieldKeyReleased(java.awt.event.KeyEvent evt)  {//GEN-FIRST:event_textfieldKeyReleased 
     // TODO add your handling code here: 

     last = Calendar.getInstance().getTimeInMillis(); 

    }//GEN-LAST:event_textfieldKeyReleased 

    private void textfieldKeyPressed(java.awt.event.KeyEvent evt) {//GEN-FIRST:event_textfieldKeyPressed 
     // TODO add your handling code here: 

     if(getTime() > 1000) 
      notifyAll(); 
     initial = Calendar.getInstance().getTimeInMillis(); 
    }//GEN-LAST:event_textfieldKeyPressed 

    /** 
    * @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(MainWindow.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); 
     } catch (InstantiationException ex) { 
      java.util.logging.Logger.getLogger(MainWindow.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); 
     } catch (IllegalAccessException ex) { 
      java.util.logging.Logger.getLogger(MainWindow.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); 
     } catch (javax.swing.UnsupportedLookAndFeelException ex) { 
      java.util.logging.Logger.getLogger(MainWindow.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); 
     } 
     //</editor-fold> 

     /* Create and display the form */ 
     java.awt.EventQueue.invokeLater(new Runnable() { 
      public void run() { 
       new MainWindow().setVisible(true); 
      } 
     }); 
    } 

    // Variables declaration - do not modify//GEN-BEGIN:variables 
    private javax.swing.JLabel counting; 
    private javax.swing.JScrollPane jScrollPane1; 
    private javax.swing.JLabel save; 
    private javax.swing.JTextArea textfield; 
    // End of variables declaration//GEN-END:variables 
} 

COUNT.JAVA

import java.util.logging.Level; 
import java.util.logging.Logger; 

/* 
* To change this license header, choose License Headers in Project Properties. 
* To change this template file, choose Tools | Templates 
* and open the template in the editor. 
*/ 

/** 
* 
* @author DEV 
*/ 
public class Count implements Runnable{ 


    Operation target; 
    Thread t; 

    public Count(Operation operation) { 

     target = operation; 
     t = new Thread(this,"Counting Thread"); 
     t.start(); 
    } 




    @Override 
    public void run() { 

     while(true){ 

      target.countWord(); 

     } 
    } 
} 

Operation.java

import java.io.FileWriter; 
import java.io.IOException; 
import java.util.StringTokenizer; 
import java.util.logging.Level; 
import java.util.logging.Logger; 

/* 
* To change this license header, choose License Headers in Project Properties. 
* To change this template file, choose Tools | Templates 
* and open the template in the editor. 
*/ 

/** 
* 
* @author DEV 
*/ 
public class Operation { 

    boolean flag= true; 
    MainWindow window ; 
    String text ; 


Operation(MainWindow window){ 
    this.window = window; 
    this.text=""; 
} 

synchronized public void save(FileWriter data){ 

    try { 

       while(flag) 
       { 
        wait(); 
       } 

       data.write(text); 

       data.close(); 
     flag = true; 

    } catch (IOException ex) { 
     Logger.getLogger(Operation.class.getName()).log(Level.SEVERE, null, ex); 
    } catch (InterruptedException ex) { 
     Logger.getLogger(Operation.class.getName()).log(Level.SEVERE, null, ex); 
    } 


} 


synchronized public void countWord(){ 


    while(!flag){ 

     try { 
      wait(); 
     } catch (InterruptedException ex) { 
      Logger.getLogger(Operation.class.getName()).log(Level.SEVERE, null, ex); 
     } 
    } 

    String result; 
    StringTokenizer token= null; 
    text = window.getInput(); 
    if(text.length() > 0) 
    { 

     token = new StringTokenizer(text); 


    result = token.countTokens() + " w, "+ text.length()+" c"; 

    window.countUpdate(result); 

    } 
    else{ 
     result =" 0 w, 0,c"; 
    } 


    flag = true; 


} 


} 

Answer 1

Count内のスレッドが無限ループを実行している：

while(true){ 
    target.countWord(); 
} 

これは、多くのCPUサイクルを消費することになります。

全体のアプローチを変更する必要があります。 event listenersを見てください。たとえば、ユーザーがキーを押すと、カウントを更新する良い機会になります。