Error - Exception in thread "AWT-EventQueue-0" java.lang.OutOfMemoryError: Java heap

I have faced this error and i could find the solution. Could anyone please solve it? Urgent. Thanks
Below is my coding:

Code:

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import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import javax.swing.JFileChooser;
import javax.swing.JOptionPane;

public class toolFrame extends javax.swing.JFrame {
   
    final JFileChooser fc = new JFileChooser(); 
    private String output = "Result.txt";
    File file = new File(output);
    TextFile tf = new TextFile();


    /** Creates new form toolFrame */
    public toolFrame() {
        super("LockText Text Encryption Tool");
        initComponents();
    }

    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                         
    private void initComponents() {

        jLabel1 = new javax.swing.JLabel();
        jTextField1 = new javax.swing.JTextField();
        jLabel2 = new javax.swing.JLabel();
        jButton1 = new javax.swing.JButton();
        jButton2 = new javax.swing.JButton();
        jButton3 = new javax.swing.JButton();
        jButton4 = new javax.swing.JButton();
        jLabel3 = new javax.swing.JLabel();
        jLabel4 = new javax.swing.JLabel();
        jButton5 = new javax.swing.JButton();
        jLabel5 = new javax.swing.JLabel();
        jScrollPane1 = new javax.swing.JScrollPane();
        jTextArea1 = new javax.swing.JTextArea();
        jScrollPane2 = new javax.swing.JScrollPane();
        jTextArea2 = new javax.swing.JTextArea();
        jButton6 = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jLabel1.setText("Enter password(secret key):");

        jLabel2.setText("Contents retrieved from file:");

        jButton1.setText("Open file");
        jButton1.setActionCommand("openFileButton");
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton1ActionPerformed(evt);
            }
        });

        jButton2.setText("Encrypt");
        jButton2.setActionCommand("encryptButton");

        jButton3.setText("Decrypt");
        jButton3.setActionCommand("decryptButton");

        jButton4.setText("Save file");
        jButton4.setActionCommand("saveFileButton");
        jButton4.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton4ActionPerformed(evt);
            }
        });

        jLabel3.setText("Output data:");

        jLabel4.setText("(*must ** digits long)");

        jButton5.setText("Close");
        jButton5.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton5ActionPerformed(evt);
            }
        });

        jLabel5.setIcon(new javax.swing.ImageIcon(getClass().getResource("/dmptextencryptiontool/resources/icon.jpg"))); // NOI18N

        jTextArea1.setColumns(20);
        jTextArea1.setRows(5);
        jScrollPane1.setViewportView(jTextArea1);

        jTextArea2.setColumns(20);
        jTextArea2.setRows(5);
        jScrollPane2.setViewportView(jTextArea2);

        jButton6.setText("Clear text area");
        jButton6.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton6ActionPerformed(evt);
            }
        });

        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)
                    .addComponent(jLabel2)
                    .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                        .addComponent(jButton1, javax.swing.GroupLayout.DEFAULT_SIZE, 147, Short.MAX_VALUE)
                        .addGap(16, 16, 16)
                        .addComponent(jButton2, javax.swing.GroupLayout.PREFERRED_SIZE, 146, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(18, 18, 18)
                        .addComponent(jButton3, javax.swing.GroupLayout.PREFERRED_SIZE, 139, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(18, 18, 18)
                        .addComponent(jButton4, javax.swing.GroupLayout.PREFERRED_SIZE, 148, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addGroup(layout.createSequentialGroup()
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(jScrollPane2, javax.swing.GroupLayout.DEFAULT_SIZE, 375, Short.MAX_VALUE)
                            .addGroup(layout.createSequentialGroup()
                                .addComponent(jLabel1)
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                .addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, 106, javax.swing.GroupLayout.PREFERRED_SIZE)
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                .addComponent(jLabel4))
                            .addComponent(jLabel3)
                            .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 375, Short.MAX_VALUE))
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                                .addComponent(jButton5, javax.swing.GroupLayout.PREFERRED_SIZE, 92, javax.swing.GroupLayout.PREFERRED_SIZE)
                                .addGap(78, 78, 78))
                            .addGroup(layout.createSequentialGroup()
                                .addGap(36, 36, 36)
                                .addComponent(jLabel5)
                                .addGap(16, 16, 16))
                            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                                .addComponent(jButton6, javax.swing.GroupLayout.PREFERRED_SIZE, 154, javax.swing.GroupLayout.PREFERRED_SIZE)
                                .addGap(33, 33, 33)))))
                .addGap(10, 10, 10))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jButton1, javax.swing.GroupLayout.DEFAULT_SIZE, 44, Short.MAX_VALUE)
                    .addComponent(jButton3, javax.swing.GroupLayout.PREFERRED_SIZE, 43, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jButton2, javax.swing.GroupLayout.DEFAULT_SIZE, 44, Short.MAX_VALUE)
                    .addComponent(jButton4, javax.swing.GroupLayout.PREFERRED_SIZE, 43, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(jLabel2)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 242, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                            .addComponent(jLabel1)
                            .addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                            .addComponent(jLabel4))
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(jLabel3)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, 218, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED))
                    .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                        .addComponent(jButton6, javax.swing.GroupLayout.PREFERRED_SIZE, 47, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(jLabel5, javax.swing.GroupLayout.PREFERRED_SIZE, 386, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(jButton5, javax.swing.GroupLayout.PREFERRED_SIZE, 43, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(4, 4, 4)))
                .addGap(23, 23, 23))
        );

        pack();
    }// </editor-fold>                       

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                       
        // button 1(open)
        //JOptionPane.showMessageDialog(null,"Opening file");
        tf.viewFile();
}

public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
              TextFile tf = new TextFile();             
                new toolFrame().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify                   
    private javax.swing.JButton jButton1;
    private javax.swing.JButton jButton2;
    private javax.swing.JButton jButton3;
    private javax.swing.JButton jButton4;
    private javax.swing.JButton jButton5;
    private javax.swing.JButton jButton6;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JLabel jLabel4;
    private javax.swing.JLabel jLabel5;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JScrollPane jScrollPane2;
    public javax.swing.JTextArea jTextArea1;
    private javax.swing.JTextArea jTextArea2;
    private javax.swing.JTextField jTextField1;
}

---

Code:

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import java.io.File;
import java.util.*;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import javax.swing.JFileChooser;
import javax.swing.JOptionPane;


public class TextFile extends toolFrame{
    private String fileName;
    File file = new File("output.txt");
    public TextFile(){
        fileName = "";
    }
    public void setFilename(String fn){
        fn = fileName;
    }

    public String getFilename(){
        return fileName;
    }

    public void viewFile(){
        JOptionPane.showMessageDialog(null,"File is opened.");
        try{
            JFileChooser loadFile = new JFileChooser();//new dialog
            File selectedFile;
            BufferedReader in;
            FileReader reader = null;

    //opens dialog if button clicked
    if (loadFile.showOpenDialog(this)==JFileChooser.APPROVE_OPTION)
    {
      //gets file from dialog
      selectedFile = loadFile.getSelectedFile();
      //makes sure files can be processed before proceeding
      if (selectedFile.canRead() && selectedFile.exists())
      {
      reader = new FileReader(selectedFile);
      }
    }

  in = new BufferedReader(reader);

    //inputLine recieves file text
    String inputLine = in.readLine();
    int lineNo = 0;
    while(inputLine!=null)
    {
      //LineNumber isn't needed, but it adds a line count on the left, nice
      lineNo++;
      //StringTokenizer tokenizer = new StringTokenizer(inputLine);

      //displays text file in the text area
      jTextArea1.append(lineNo+") "+inputLine+"\n");
      //next line in File opened
      inputLine = in.readLine();
    }
    //close stream, files stops loading
    in.close();
  }
  //catches input/output exceptions and all subclasses exceptions
  catch(IOException e)
  {
    jTextArea1.append("Error When Processing File:\n" + e.getMessage()+"\n");
  }
  //catches nullpointer exception, file not found
  catch(NullPointerException e)
  {
    jTextArea1.append("Open File Is Cancelled:\n" + e.getMessage()+"\n");
  }
       
}
}

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Moderator Edit: Code tags added

i couldnt find the solution**
and the image attached is the error message appeared after few minutes it runs.
My problem is when I run it, there is nothing come out but the coding part got no problem when compiled.
Any helps are appreciated so much.

Hi,

Firstly you should apply code formatting to any code you send. It makes it much easier to read ^_^
You can do this by highlighting code and pressing the "#" symbol top right.

Secondly, if you read the message it tells you have run out of memory.

This is caused by several things. Firstly, you might not be letting the Garbage Collector run its job - make sure you delete all pointers to unecessary objects.

Secondly, it could be because you genuinly need a lot of memory - for a large file or picture. The default heap size for java is 128MB. If you think you need more than this, you can use from commandline:

Code:

---

    // Sets the maximum size to 256MB
    java -Xmx256m <yourprogramname>
    // Sets the minimum size to 128MB and maximum size to 256MB
    java -Xms128m -Xmx256 <yourprogramname>

---

The minimum size is not necessary, but if you need lots of memory it is recommended (it is faster).

Only use this code if you genuinly need it, if you have a memory leak then it only hides it for longer!

Your code looks like your using netbeans.
If thats the case, then you can right click on your project -> Properties -> Categories -> Run.
Put the code into the vmOptions box.

Hope this helps and good luck.
Berkeleybross

First, Berkeleybross thanks you so muchhh for replying.
Yes. I'm using the Netbeans.
I have tried your suggestion and the problem of out of memory is solved. It is helpful. Thanks dude!
However, there is another error comes out as the image attached.
Can you tell me whats the problem?


Regards,
GAN

I think you misunderstood my directions for netbeans usage.

The code for vmOptions should be something like

Code:

---

-Xmx256m -Xms128m

---

If that doesnt fix it, please can you explain more about the problem i.e. when does it occur, what did you do that caused it etc

Berkeleybross