Confusing comments....help plz

hi, i was reading a Operating System Tutorial......and i got some confusion.
Ok, let me explain first............
i was reading about Process and Threads (Chapter 2 ). There 2 keyword you will find "Mutual Exclusion" AND "Semaphore"...right ?
Q1. is this Mutual Exclusion is a solution to avoid data inconsistency ?
is this Semaphore a way how to implement Mutual Exculsion ?
I am not clear about these two . It seems to me both of them are same. can u clarify about its functionalities and difference? ( i mean who works for whom )
Q2. Now Coming down to implementaion using JAVA.
what are equivalents of Mutual Exclusion and what are equivalents of Semaphore ?

But we know it is not the absolute solution
(Bcoz deadlock can occur even if you follow the
Mutual Exclusion Principle )......then why do we
rush for it ? after all its a faulty solution!!Mutual exclusion is what we aim for. Then there are problems associated with it and flaws in different solutions we came up with to achieve it. But that doesn't disqualify the principle. And we must know one thing. If we cannot guarantee mutual exclusivity the there will be bugs in our program.
Look , Semaphore S is either incremented or
decremented by 1 ..........No NO, I dont see in
JAVA this kind of incrementaion or decrementation
in Synchronisation code. DO i have to believe
the so called Semaphore is absent
] in JAVA ?A semaphore can be at different levels (of abstraction). At the lowest level its hidden (method synchronization). At higher levels it's up to you to implement the kind of semaphore you desire using the means available (syncronize, wait, notify etcetera). Version 1.5 offers more, from atomic types to collections with special synchronized bahviour.

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Run Time error!!!Help plz

hi ..
every time i run my application i get this error which i can't understand where exactly the error is
can any one help plz
)at javax.swing.JLayeredPane.paint(JLayeredPane.java:546
)at javax.swing.JComponent.paintChildren(JComponent.java:498
)at javax.swing.JComponent.paint(JComponent.java:669
)at java.awt.GraphicsCallback$PaintCallback.run(GraphicsCallback.java:23
:at sun.awt.SunGraphicsCallback.runOneComponent(SunGraphicsCallback.java
)54
at sun.awt.SunGraphicsCallback.runComponents(SunGraphicsCallback.java:91
)at java.awt.Container.paint(Container.java:960
)at javax.swing.JFrame.update(JFrame.java:329
)at sun.awt.RepaintArea.update(RepaintArea.java:337
)at sun.awt.windows.WComponentPeer.handleEvent(WComponentPeer.java:200
)at java.awt.Component.dispatchEventImpl(Component.java:2663
)at java.awt.Container.dispatchEventImpl(Container.java:1213
)at java.awt.Window.dispatchEventImpl(Window.java:914
)at java.awt.Component.dispatchEvent(Component.java:2497
)at java.awt.EventQueue.dispatchEvent(EventQueue.java:339
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchTh
)read.java:131
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThre
)ad.java:98
)at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93
)at java.awt.EventDispatchThread.run(EventDispatchThread.java:85
this is part of the code:
public void actionPerformed(ActionEvent e)
    FileInputStream fis = null;
    if (e.getSource() == add) //The ADD button.
      //User has not populated all the input fields.
      if(name.getText().equals("")|| address.getText().equals("")|| phone.getText().equals("")|| sex.getText().equals("")|| dob.getText().equals("")|| photo.getText().equals(""))
        JOptionPane.showMessageDialog(null, "Please fill in all the fields","Missing Fields",JOptionPane.INFORMATION_MESSAGE);
      else
        // save the new customer:
        try
          //1. take the customer's data and photo:
          int    userId          = Integer.parseInt(id.getText());
          String userName      = name.getText();
          String userAddress      = address.getText();
          String userPhone      = phone.getText();
          String userSex      = sex.getText();
          String userDateBirth      = dob.getText();
          //String userDateBirth=Date.parse(dob);
          String photoName      = photo.getText();
          String audioName=   audio.getText();
          File   file           = new File(photoName);
          int    fileLength      = (int)file.length();
          //2. Set the user's photo into the photoHolder:
          photoHolder.setVisible(false);
          photoHolder = null;
          comments.setVisible(false);
          comments = null;
          Icon[] custPhotos = {new ImageIcon(photoName)};
          JList photosList = new JList(custPhotos);
          photosList.setFixedCellHeight(100);
          photosList.setFixedCellWidth(80);
          photoHolder = new JPanel();
          photoHolder.add(photosList);
          makeComments();
          //3. Insert the data and photo into the database:
          if(fileLength > 0)
            fis = new FileInputStream(file);
            String query = " INSERT INTO CUSTOMER VALUES('"+userId+"', '"+ userName+ "', '"+ userAddress+ "', " +" '"+ userPhone+ "', '"+ userSex+ "', '"+ userDateBirth+ "', ?,?,? ) ";
            PreparedStatement pstmt = conn.prepareStatement(query);
            pstmt.setBinaryStream(1, fis, fileLength);
              pstmt.setString(2,photoName);
              pstmt.setString(3,audioName);
            pstmt.executeUpdate();
            comments.setText(userName+", added.");
          else
            String query = " INSERT INTO CUSTOMER (id, name, address, phone, sex, dob) VALUES('"+userId+"', '"+userName+"', '"+userAddress+"', '"+userPhone+"', '"+userSex+"', '"+userDateBirth+"') ";
            stat.executeUpdate(query);
            comments.setText("Customer saved without a photo.");
          backPanel.add(photoHolder);
          backPanel.add(comments);
          updateTable();
          //AddScroll();
        } //try
        catch (Exception ee)
           //The danger of putting creating the JOptionPane in here is that it will show the same message regardless of the error.
            JOptionPane.showMessageDialog(null, "Customers CPR already exits!!Please enter another CPR","Invalid",JOptionPane.INFORMATION_MESSAGE);
          System.out.println("Caught exception in add action: " + ee);
          ee.printStackTrace();
        } //catch
      } //if
    }//add button

hi...
i got where the error is..
now i have another problem..
Connecting to database..
Valid Login
Caught updateTable exception: java.lang.ArrayIndexOutOfBoundsException
java.lang.ArrayIndexOutOfBoundsException
at UtilityMethods.updateTable(UtilityMethods.java:305)
(which is this line:
tableData[currentRow] = fieldString;)-----> i did this because one of the fields will be a Date and the others are strings
at UtilityMethods.updateTable(UtilityMethods.java:429)
at Login.validLogin(Login.java:114)
at Login.actionPerformed(Login.java:80)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:14
50)
at javax.swing.AbstractButton$ForwardActionEvents.actionPerformed(Abstra
ctButton.java:1504)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel
.java:378)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:250
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonL
istener.java:216)
at java.awt.Component.processMouseEvent(Component.java:3715)
at java.awt.Component.processEvent(Component.java:3544)
at java.awt.Container.processEvent(Container.java:1164)
at java.awt.Component.dispatchEventImpl(Component.java:2593)
at java.awt.Container.dispatchEventImpl(Container.java:1213)
at java.awt.Component.dispatchEvent(Component.java:2497)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:2451
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:2216)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:2125)
at java.awt.Container.dispatchEventImpl(Container.java:1200)
at java.awt.Window.dispatchEventImpl(Window.java:914)
at java.awt.Component.dispatchEvent(Component.java:2497)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:339)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchTh
read.java:131)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThre
ad.java:98)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:85)
this is the code :
void updateTable()
      ResultSet results = null;
      ResultSet results1 = null;
      try
        //Get the number of rows in the table so we know how big to make the data array..
        int rowNumbers = 0;
        int columnCount = 6;
        results = stat.executeQuery("SELECT COUNT(*) FROM CUSTOMER ");
        if(results.next())
          rowNumbers = results.getInt(1);
        } //if
        if(rowNumbers == 0)
        rowNumbers = 1;
        tableData = new String[rowNumbers][columnCount];
        //Initialize the data array with "" so we avoid possibly having nulls in it later..
        for(int i =0;i<tableData.length;i++)
          for(int j=0;j<tableData[0].length;j++)
          tableData[i][j] = "";
        //Populate the data array with results of the query on the database..
        int currentRow = 0;
         SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy");
        results1 = stat.executeQuery("SELECT * FROM CUSTOMER ORDER BY ID");
        while (results1.next())
          for(int i = 0; i < columnCount; i++){
          Object field = results1.getObject(i + 1);
          // actually this next line should be put outside your loop so you don't keep creating this object
          // or whatever format you want
          String fieldString;
          if (field instanceof Date)
                 fieldString = sdf.format((Date) field);
                 else
                      fieldString = field.toString();
                      tableData[currentRow] = fieldString;
//tableData[currentRow][i] = results1.getString(i + 1);
currentRow++;
} //while
}//for
final String[] colName = { "CPR", "Name", "Address", "Phone", "Sex", "Date OF Birth" };
TableModel pageModel = new AbstractTableModel()
public int getColumnCount()
return tableData[0].length;
} //getColumnCount
public int getRowCount()
return tableData.length;
} //getRowCount
public Object getValueAt(int row, int col)
return tableData[row][col];
} //getValueAt
public String getColumnName(int column)
return colName[column];
} //getcolName
public Class getColumnClass(int col)
return getValueAt(0, col).getClass();
} //getColumnClass
public boolean isCellEditable(int row, int col)
return false;
} //isCellEditable
public void setValueAt(String aValue, int row, int column)
tableData[row][column] = aValue;
} //setValueAt
//dataTable.setValue( new JScrollBar(JScrollBar.HORIZONTAL), 2,1 );
}; //pageModel
//Create the JTable from the table model:
JTable dataTable = new JTable(pageModel);
// dataTable.setModel();

Im new to the 5g ipod help plz

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Yes.

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Download and install the free trial version of WinRAR:
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jennyspeedy* wrote:
i dont want to lose any of my pictues of my kids im not sure if ive backed it up before if i have it would of been a long time ago plz help me thanks
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Itunes help plz respond asap

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Confusing comments....help plz

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