Need help with Program Please!

Question

// Name: John Weir 02/03/2006
Please read the comments as they will explain what help I need.
All help greatly appreciated! Am new to working with GUI.
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
public class FeverDiagnosis extends JFrame
     // diagnoisis constants
     private final String MENIGITIS = "menigitis";
     private final String DIGESTIVE_TRACT_INFECTION = "digestive tract infection";
     private final String PNEUMONIA_OR_AIRWAYS_INFECTION  ="pneumonia or airways infection";
     private final String VIRAL_INFECTION = "viral infection";
     private final String THROAT_INFECTION = "throat infection";
     private final String KIDNEY_INFECTION = "kidney infection";
     private final String URINARY_INFECTION = "urinary tract infection";
     private final String SUNSTROKE_OR_HEAT_EXHAUSTION = "sunstroke or heat exhaustion";
     // symptom constants
     private final String FEVER = "fever";
     private final String COUGHING = "coughing";
     private final String HEADACHE = "headache";
     private final String BREATHING_WITH_DIFFICULTY = "shortness of breath, wheezing, or coughing up phlegm";
     private final String ACHING_BONES_JOINTS = "aching bones or joints";
     private final String RASH = "rash";
     private final String SORE_THROAT = "sore throat";
     private final String BACK_PAIN_AND_CHILLS_AND_FEVER = "back pain just above the waist with chills and fever";
     private final String URINARY_DIFFICULTY = "pain urinating or are urinating more often";
     private final String TOO_MUCH_SUN = "sun overexposure due to spending the day in the sun or in hot conditions";
     public final String VOMITING_OR_DIARRHEA = "vomitting spell or diarrhea";
     private final String MENIGITIS_POSSIBILITIES =
                      "pain when bending your head forward,\n"
                    + "    nausea or vomiting, eye ache from \n"
                    + "    bright lights, drowsiness or confusion";
     // GUI varibles
     private JTextArea textArea;
     private JFrame theFrame;
     private JLabel stuff2;
     private JButton b1;
     private JButton b2;
     // instance variable
     private String symptoms = "";
     private Scanner cin = new Scanner (System.in);
     char response;
     String input;
     public FeverDiagnosis()
          JFrame.setDefaultLookAndFeelDecorated(true);
          JFrame theFrame = new JFrame("John Weir");
          theFrame.setSize(650, 400);
          Dimension frameSize = theFrame.getSize();
          Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
          theFrame.setLocation((screenSize.width - frameSize.width)/2,(screenSize.height - frameSize.height)/2);
          theFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          Container contentPane = theFrame.getContentPane();
          theFrame.getContentPane().setLayout(new FlowLayout());
          JLabel stuff2 = new JLabel("Test");
          textArea = new JTextArea(12,50);
          textArea.setEditable(true);
          textArea.setBackground(Color.black);
          textArea.setForeground(Color.green);
          textArea.setFont(new Font("Serif", Font.ITALIC, 16));
          textArea.setLineWrap(true);
          textArea.setWrapStyleWord(true);
          b1 = new JButton("Yes");
          b2 = new JButton("No");
          contentPane.add(stuff2);
          contentPane.add(new JScrollPane(textArea));
          contentPane.add(b1);
          b1.setEnabled(true);
          contentPane.add(b2);
          b2.setEnabled(true);
          ActionListener l = new ActionListener()
            public void actionPerformed(ActionEvent e)
               if((e.getSource() == b1))
               //   HELP NEEDED
               //   NEED BUTTON TO PASS
               //   STRING VALUE "Y" TO
               //   METHOD: have(String s)
               input.equals("y");
               else
               if((e.getSource() == b2))
          b1.addActionListener(l);
          b2.addActionListener(l);
          theFrame.setVisible(true);
          theRules();
public void theRules()
     displayNote();
     if (! have(FEVER) )
          displayUnsure();
     else
     if(are(COUGHING))
          if( are(BREATHING_WITH_DIFFICULTY))
               addSymptom( PNEUMONIA_OR_AIRWAYS_INFECTION );
               displayDiagnosis(PNEUMONIA_OR_AIRWAYS_INFECTION);
          }else
          if(have(HEADACHE))
               addSymptom( VIRAL_INFECTION );
               displayDiagnosis(VIRAL_INFECTION);
          }else
          if(have(ACHING_BONES_JOINTS))
               addSymptom( VIRAL_INFECTION );
               displayDiagnosis(VIRAL_INFECTION);
          }else
          if(have(RASH))
               displayUnsure();
          }else
          if(have(SORE_THROAT))
               addSymptom( THROAT_INFECTION );
               displayDiagnosis(THROAT_INFECTION);
          }else
          if(have(BACK_PAIN_AND_CHILLS_AND_FEVER))
               addSymptom( KIDNEY_INFECTION );
               displayDiagnosis(KIDNEY_INFECTION);
          }else
          if(have(URINARY_DIFFICULTY))
               addSymptom( URINARY_INFECTION );
               displayDiagnosis(URINARY_INFECTION);
          }else
          if(have(TOO_MUCH_SUN))
               addSymptom( SUNSTROKE_OR_HEAT_EXHAUSTION );
               displayDiagnosis(SUNSTROKE_OR_HEAT_EXHAUSTION);
          }else
               displayUnsure();
          else
          if(have(HEADACHE))
               addSymptom(VIRAL_INFECTION);
               displayDiagnosis(VIRAL_INFECTION);
          }else
          if(are(MENIGITIS_POSSIBILITIES))
               addSymptom( MENIGITIS );
               displayDiagnosis(MENIGITIS);
          }else
          if(are(VOMITING_OR_DIARRHEA))
               addSymptom( DIGESTIVE_TRACT_INFECTION );
               displayDiagnosis(DIGESTIVE_TRACT_INFECTION);
          }else
          displayUnsure();
     public void displayNote()
          textArea.append("\n\n"
               + "Fever Diagnostic Tool\n"
               + "---------------------\n\n"
               + "Please note that this program performs no true diagnostic activity.\n"
               + "No decisions should be made based upon the tool's analysis. If users\n"
               + "have a fever, they should contact their doctor.\n\n");
     public boolean have(String s)
          // prompt and extract
          textArea.append("Do you have you " + s + " (y, n): " + "\n");
          // NEED BUTTON TO PASS STRING  FROM ActionPerformed
          // AND HAVE IT RETURNED AS A CHAR RESPONCE!
          input = cin.nextLine();
          response = (char) Character.toLowerCase(input.charAt(0));
          while ( (response != 'y') && (response != 'n') )
               textArea.append("Are you " + s + " (y, n): " + "\n");
               input = cin.nextLine();
               response = (char) Character.toLowerCase(input.charAt(0));
          textArea.append("");
          return response == 'y';
     private boolean are(String s)
          textArea.append("Are you " + s + " (y, n): " + "\n");
          input = cin.nextLine();
          char response = (char) Character.toLowerCase(input.charAt(0));
          while ( (response != 'y') && (response != 'n') )
               textArea.append("Are you " + s + " (y, n): " + "\n");
               input = cin.nextLine();
               response = (char) Character.toLowerCase(input.charAt(0));
          textArea.append("");
          return response == 'y';
     public void addSymptom(String s)
          symptoms += "*   " + s + "\n";
     public void displayDiagnosis(String diagnosis)
          textArea.setText("");
          textArea.append("\nSymptoms:\n" + symptoms + "\n" + "Diagnosis"
               + "\n   Possibilities include " + diagnosis  + "\n");
          textArea.append("\n");
          //System.exit(0);
     public void displayUnsure()
          textArea.append("\nInsufficient information to make a diagnosis" + "\n");
          textArea.append("\n");
          //System.exit(0);
     public static void main(String[] args)
          new FeverDiagnosis();
}

Answer 1

If you're looking to use a JTextArea as a console you can use these two classes
you are free to use and modify these classes but please do not change the package or take credit for it as your own work.
TextAreaReader.java
=================
* Created on Jul 7, 2005 by @author Tom Jacobs
package tjacobs;
import java.awt.TextArea;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.TextEvent;
import java.awt.event.TextListener;
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import javax.swing.JFrame;
import javax.swing.JTextArea;
public class TextAreaReader extends Reader implements KeyListener {
     JTextArea mJArea;
     TextArea mAWTArea;
     Object mKeyLock = new Object();
     Object mLineLock = new Object();
     String mLastLine;
     int mLastKeyCode = 1;
     public TextAreaReader(JTextArea area) {
          super();
          mJArea = area;
          mJArea.addKeyListener(this);
     public TextAreaReader(TextArea area) {
          super();
          mAWTArea = area;
          mAWTArea.addKeyListener(this);
     public void keyPressed(KeyEvent ke) {
          mLastKeyCode = ke.getKeyCode();
          synchronized(mKeyLock) {
               mKeyLock.notifyAll();
          if (ke.getKeyCode() == KeyEvent.VK_ENTER) {
               if (mJArea != null) {
                    String txt = mJArea.getText();
                    int idx = txt.lastIndexOf('\n', mJArea.getCaretPosition() - 1);
                    mLastLine = txt.substring(idx != -1 ? idx : 0, mJArea.getCaretPosition());//txt.length());
                    synchronized(mLineLock) {
                         mLineLock.notifyAll();
               else {
                    String txt = mAWTArea.getText();
                    int idx = txt.lastIndexOf('\n', mAWTArea.getCaretPosition() - 1);
                    mLastLine = txt.substring(idx != -1 ? idx : 0, mAWTArea.getCaretPosition());//txt.length());
                    synchronized(mLineLock) {
                         mLineLock.notifyAll();
     public void keyReleased(KeyEvent ke) {
     public void keyTyped(KeyEvent ke) {
     public int read(char[] arg0, int arg1, int arg2) throws IOException {
          throw new IOException("Not supported");
     public String readLine() {
          synchronized(mLineLock) {
               try {
                    mLineLock.wait();
               catch (InterruptedException ex) {
          return mLastLine;
     public int read() {
          synchronized(mKeyLock) {
               try {
                    mKeyLock.wait();
               catch (InterruptedException ex) {
          return mLastKeyCode;
     public void close() throws IOException {
          // TODO Auto-generated method stub
     public static void main(String args[]) {
          JFrame f = new JFrame("TextAreaInput Test");
          JTextArea area = new JTextArea();
          final TextAreaReader tar = new TextAreaReader(area);
          f.add(area);
          Runnable r1 = new Runnable() {
               public void run() {
                    while (true) {
                         int code = tar.read();
                         System.out.println("read: " + code);
          Runnable r2 = new Runnable() {
               public void run() {
                    while (true) {
                         String line = tar.readLine();
                         System.out.println("read line: " + line);
          Thread t1 = new Thread(r1);
          Thread t2 = new Thread(r2);
          t1.start();
          t2.start();
          f.setBounds(100, 100, 200, 200);
          f.setVisible(true);
     public InputStream toInputStream() {
          return new MyInputStream();
     private class MyInputStream extends InputStream {
          public int read() {
               return TextAreaReader.this.read();
==================
TextAreaOutputStream
==================
* Created on Mar 13, 2005 by @author Tom Jacobs
package tjacobs;
import java.io.IOException;
import java.io.OutputStream;
import javax.swing.JTextArea;
import javax.swing.text.JTextComponent;
public class TextAreaOutputStream extends OutputStream {
     public static final int DEFAULT_BUFFER_SIZE = 1;
     JTextArea mText;
     byte mBuf[];
     int mLocation;
     public TextAreaOutputStream(JTextArea component) {
          this(component, DEFAULT_BUFFER_SIZE);
     public TextAreaOutputStream(JTextArea component, int bufferSize) {
          mText = component;
          if (bufferSize < 1) bufferSize = 1;
          mBuf = new byte[bufferSize];
          mLocation = 0;
     @Override
     public void write(int arg0) throws IOException {
          //System.err.println("arg = "  + (char) arg0);
          mBuf[mLocation++] = (byte)arg0;
          if (mLocation == mBuf.length) {
               flush();
     public void flush() {
          mText.append(new String(mBuf, 0, mLocation));
          mLocation = 0;
          try {
               Thread.sleep(1);
          catch (Exception ex) {}
}