create a login form in java

is this an application or the user will log in though a website ? Either task is easy to perform.

I recommend using STRUTS http://jakarta.apache.org/struts/

down load the jar file.  the jar file contains a demo.  It's demo has a login page which does validation.

The big bonus is that you'll be using a very robust and stable framework.  Since your starting out in Java, you might as well start by writing good code.  STRUTS implements the MVC model.  

Sounds difficult but since you have years of programming experience you shouldn't have too much difficulty.

- tekel

rahul i copied the code and pasted it. Got a few errors which were fixed easily except these

D:\electric\JavaCodes\JavaPrograms\GetParam\Login.java:17: cannot resolve symbol
symbol  : class MySQLConn  
location: class Login
 private MySQLConn mysql;
         ^
D:\electric\JavaCodes\JavaPrograms\GetParam\Login.java:25: cannot resolve symbol
symbol  : class MySQLConn  
location: class Login
   mysql=new MySQLConn(config);
             ^
D:\electric\JavaCodes\JavaPrograms\GetParam\Login.java:60: cannot resolve symbol
symbol  : class VerticalFlowLayout  
location: class Login
   panelcontainer.setLayout(new VerticalFlowLayout());
                                ^
D:\electric\JavaCodes\JavaPrograms\GetParam\Login.java:108: cannot resolve symbol
symbol: variable Stars  
                   Stars.closeLoginFrame();
                   ^
4 errors


Please could u also send the code for the MySQL connection and other classes. I think they are missing.

rahul i copied the code and pasted it. Got a few errors which were fixed easily except these

D:\electric\JavaCodes\JavaPrograms\GetParam\Login.java:17: cannot resolve symbol
symbol  : class MySQLConn  
location: class Login
 private MySQLConn mysql;
         ^
D:\electric\JavaCodes\JavaPrograms\GetParam\Login.java:25: cannot resolve symbol
symbol  : class MySQLConn  
location: class Login
   mysql=new MySQLConn(config);
             ^
D:\electric\JavaCodes\JavaPrograms\GetParam\Login.java:60: cannot resolve symbol
symbol  : class VerticalFlowLayout  
location: class Login
   panelcontainer.setLayout(new VerticalFlowLayout());
                                ^
D:\electric\JavaCodes\JavaPrograms\GetParam\Login.java:108: cannot resolve symbol
symbol: variable Stars  
                   Stars.closeLoginFrame();
                   ^
4 errors


Please could u also send the code for the MySQL connection and other classes. I think they are missing.

rahul i copied the code and pasted it. Got a few errors which were fixed easily except these

D:\electric\JavaCodes\JavaPrograms\GetParam\Login.java:17: cannot resolve symbol
symbol  : class MySQLConn  
location: class Login
 private MySQLConn mysql;
         ^
D:\electric\JavaCodes\JavaPrograms\GetParam\Login.java:25: cannot resolve symbol
symbol  : class MySQLConn  
location: class Login
   mysql=new MySQLConn(config);
             ^
D:\electric\JavaCodes\JavaPrograms\GetParam\Login.java:60: cannot resolve symbol
symbol  : class VerticalFlowLayout  
location: class Login
   panelcontainer.setLayout(new VerticalFlowLayout());
                                ^
D:\electric\JavaCodes\JavaPrograms\GetParam\Login.java:108: cannot resolve symbol
symbol: variable Stars  
                   Stars.closeLoginFrame();
                   ^
4 errors


Please could u also send the code for the MySQL connection and other classes. I think they are missing.

rahul i copied the code and pasted it. Got a few errors which were fixed easily except these

D:\electric\JavaCodes\JavaPrograms\GetParam\Login.java:17: cannot resolve symbol
symbol  : class MySQLConn  
location: class Login
 private MySQLConn mysql;
         ^
D:\electric\JavaCodes\JavaPrograms\GetParam\Login.java:25: cannot resolve symbol
symbol  : class MySQLConn  
location: class Login
   mysql=new MySQLConn(config);
             ^
D:\electric\JavaCodes\JavaPrograms\GetParam\Login.java:60: cannot resolve symbol
symbol  : class VerticalFlowLayout  
location: class Login
   panelcontainer.setLayout(new VerticalFlowLayout());
                                ^
D:\electric\JavaCodes\JavaPrograms\GetParam\Login.java:108: cannot resolve symbol
symbol: variable Stars  
                   Stars.closeLoginFrame();
                   ^
4 errors


Please could u also send the code for the MySQL connection and other classes. I think they are missing.

these are the errors to connect to the MySQL database
in the linux machine for that u need a mysql driver

since u r storing ur password in a file or something, remove MySQL statemnents.

instead add the file access statement.

for verticalflow layout take this codeimport java.awt.*;

/**
 * A vertical flow layout is used to lay out components in a panel.
 * It will arrange the components from top to bottom until no more components fit in the same column.
 * The columns can be aligned vertically.
 *
 * @version 1.0.2
 */
public class VerticalFlowLayout
    implements LayoutManager
{

    /**
     * The top alignment variable.
     */
    public static final int TOP = 1;

    /**
     * The centre alignment variable.
     */
    public static final int CENTER       = 0;

    /**
     * The bottom alignment variable.
     */
    public static final int BOTTOM = 2;
    /**
     * Vertical alignment left
     */
    public static final int LEFT = 3;
    /**
     * Vertical alignment right
     */
    public static final int RIGHT = 4;

    int align;
    int vAlign; // Tim added horizontal alignment
    int hgap;
    int vgap;
    boolean maximise;

    /**
     * Constructs a new layout with a centered alignment and a
     * default 5-unit horizontal and vertical gap.
     */
    public VerticalFlowLayout()
    {
        this(CENTER, 5, 5, false);
    }

    /**
     * Constructs a new layout with the specified alignment and a
     * default 5-unit horizontal and vertical gap.
     * @param align the alignment value
     */
    public VerticalFlowLayout(int align)
    {
        this(align, 5, 5, false);
    }

    /**
     * Constructs a new layout with the specified alignment and gap
     * values.
     * @param align the alignment value
     * @param hgap the horizontal gap variable
     * @param vgap the vertical gap variable
     */
    public VerticalFlowLayout(int align, int hgap, int vgap)
    {
        this(align, hgap, vgap, false);
    }

    /**
     * Constructs a new layout with the specified alignment and gap
     * values.
     * @param align the alignment value
     * @param hgap the horizontal gap variable
     * @param vgap the vertical gap variable
     */
    public VerticalFlowLayout(int align, int hgap, int vgap, boolean maximise)
    {
        if (align!=TOP && align!=CENTER && align!=BOTTOM)
            throw new IllegalArgumentException("illegal alignment value:"+align);
        if (hgap<0)
            throw new IllegalArgumentException("horizontal gap is less than 0");
        if (vgap<0)
            throw new IllegalArgumentException("vertical gap is less than 0");
        this.align = align;
        this.hgap = hgap;
        this.vgap = vgap;
        this.maximise = maximise;
    }

    /**
     * Returns the alignment value for this layout (TOP, CENTER, or BOTTOM).
     */
    public int getAlignment()
    {
        return align;
    }

    /**
     * Sets the alignment value for this layout.
     * @param align the alignment value (TOP, CENTER, or BOTTOM).
     */
    public void setAlignment(int align)
    {
        if (align!=TOP && align!=CENTER && align!=BOTTOM)
            throw new IllegalArgumentException("illegal alignment value:"+align);
        this.align = align;
    }
    /**
     * Set the verical alignment value.
     * @param aligns (LEFT, CENTER, or RIGHT)
     */
    public void setHorizontalAlignment(int align)
    {
        if (align!=LEFT && align!=RIGHT && align!=CENTER)
            throw new IllegalArgumentException("illegal alignment value:"+align);
        this.vAlign = align;
    }
    /**
     * Returns the horizontal gap between components.
     */
    public int getHgap()
    {
        return hgap;
    }

    /**
     * Sets the horizontal gap between components.
     * @param hgap the horizontal gap between components
     */
    public void setHgap(int hgap)
    {
        if (hgap<0)
            throw new IllegalArgumentException("horizontal gap is less than 0");
        this.hgap = hgap;
    }

    /**
     * Returns the vertical gap between components.
     */
    public int getVgap()
    {
        return vgap;
    }

    /**
     * Sets the vertical gap between components.
     * @param vgap the vertical gap between components
     */
    public void setVgap(int vgap)
    {
        if (vgap<0)
            throw new IllegalArgumentException("vertical gap is less than 0");
        this.vgap = vgap;
    }

    /**
     * Adds the specified component to the layout. Not used by this class.
     * @param name the name of the component
     * @param comp the the component to be added
     */
    public void addLayoutComponent(String name, Component comp)
    {}

    /**
     * Removes the specified component from the layout. Not used by this class.
     * @param comp the component to remove
     */
    public void removeLayoutComponent(Component comp) {
    }

    /**
     * Returns the preferred dimensions for this layout given the components
     * in the specified target container.
     * @param target the component which needs to be laid out
     * @see Container
     * @see #minimumLayoutSize
     */
    public Dimension preferredLayoutSize(Container target)
    {
        Dimension dim = new Dimension(0, 0);
        int nmembers = target.getComponentCount();
        for (int i=0; i<nmembers; i++)
        {
            Component m = target.getComponent(i);
            if (m.isVisible())
            {
                Dimension d = maximise ? m.getMaximumSize() : m.getPreferredSize();
                dim.width = Math.max(dim.width, d.width);
                if (i>1)
                    dim.height += vgap;
                dim.height += d.height;
            }
        }
        Insets insets = target.getInsets();
        dim.width += insets.left + insets.right + hgap*2;
        dim.height += insets.top + insets.bottom + vgap*2;
        return dim;
    }

    /**
     * Returns the minimum dimensions needed to layout the components
     * contained in the specified target container.
     * @param target the component which needs to be laid out
     * @see #preferredLayoutSize
     */
    public Dimension minimumLayoutSize(Container target)
    {
        Dimension dim = new Dimension(0, 0);
        int nmembers = target.getComponentCount();
        for (int i=0; i<nmembers; i++)
        {
            Component m = target.getComponent(i);
            if (m.isVisible())
            {
                Dimension d = m.getMinimumSize();
                dim.width = Math.max(dim.width, d.width);
                if (i>0)
                    dim.height += vgap;
                dim.height += d.height;
            }
        }
        Insets insets = target.getInsets();
        dim.width += insets.left + insets.right + hgap*2;
        dim.height += insets.top + insets.bottom + vgap*2;
        return dim;
    }

    /**
     * Centers the elements in the specified column, if there is any slack.
     * @param target the component which needs to be moved
     * @param x the x coordinate
     * @param y the y coordinate
     * @param width the width dimensions
     * @param height the height dimensions
     * @param columnStart the beginning of the column
     * @param columnEnd the the ending of the column
     */
    private void moveComponents(Container target, int x, int y, int width, int height, int columnStart, int columnEnd)
    {
        switch (align)
        {
          case TOP:
            break;
          case CENTER:
            y += height/2;
            break;
          case BOTTOM:
            y += height;
            break;
        }
        for (int i=columnStart; i<columnEnd; i++)
        {
            Component m = target.getComponent(i);
            Rectangle mbounds = m.getBounds();
            int X = x+(width-mbounds.width)/2; //center
            if (m.isVisible())
            {
                if (vAlign == LEFT)
                    X = x;
                else if (vAlign == RIGHT)
                    X = x+(width-mbounds.width);
                m.setLocation(X, y);
                y += vgap+mbounds.height;
            }
        }
    }

    /**
     * Lays out the container. This method will actually reshape the
     * components in the target in order to satisfy the constraints of
     * the BorderLayout object.
     * @param target the specified component being laid out.
     * @see Container
     */
    public void layoutContainer(Container target)
    {
        Insets insets = target.getInsets();
        Rectangle bounds = target.getBounds();
        int maxheight = bounds.height - (insets.top + insets.bottom + vgap*2);
        int nmembers = target.getComponentCount();
        int y = 0, x = insets.left + hgap;
        int rowv = 0, start = 0;

        for (int i=0; i<nmembers; i++)
        {
            Component m = target.getComponent(i);
            if (m.isVisible())
            {
                Dimension d = maximise ? m.getPreferredSize() : m.getPreferredSize();
                m.setSize(d.width, d.height);

                if ((y==0) || ((y+d.height) <= maxheight))
                {
                    if (y>0)
                        y += vgap;
                    y += d.height;
                    rowv = Math.max(rowv, d.width);
                }
                else
                {
                    moveComponents(target, x, insets.top+vgap, rowv, maxheight-y, start, i);
                    x += hgap+rowv;
                    y = d.height;
                    rowv = d.width;
                    start = i;
                }
            }
        }
        moveComponents(target, x, insets.top+vgap, rowv, maxheight-y, start, nmembers);
    }

    /**
     * Returns the string representation of this layout's values.
     */
    public String toString()
    {
        StringBuffer buffer = new StringBuffer();
        buffer.append(getClass().getName());
        buffer.append("[hgap=");
        buffer.append(hgap);
        buffer.append(",vgap=");
        buffer.append(vgap);
        switch (align) {
          case TOP:
            buffer.append(",align=top");
            break;
          case CENTER:
            buffer.append(",align=center");
            break;
          case BOTTOM:
            buffer.append(",align=bottom");
            break;
        }
        buffer.append("]");
        return buffer.toString();
    }
}

rahul i have compiled the code successfully, now how do I run it.

I mean how do I use the Login constructor to open the Login form.

was having the problem running it using JCreator 2.5

but when ran from command prompt by supplying the ClassPath for tools.jar, it ran successfully. rahul can u explain y tools.jar was required in the classpath?
Also i noticed you did not add the

this.show();

line in the JPanel code to display the login form, is it that u missed it or are there other ways to display this form after the constructor is created?

Thanks.

Nomi.