ActiveX Programming Unleashed CD/AXU.iso/visualj/msdev/samples/microsoft/daosample/simpledao.java

Java Source | 1996-08-27 | 15.8 KB | 521 lines

//******************************************************************************
// simpledao.java:    Applet
//
//******************************************************************************
import java.applet.*;
import java.awt.*;
import simpledaoframe;

// Creates the DAO DBEngine use the license
import dao_dbengine;

import dao3032.*;
import com.ms.com.Variant;

// SimpleForm is the data entry form for the sample
class SimpleForm extends Panel
{
    // Access to the data
    Recordset m_recordset;

    // The fields in the form
    TextField field1;
    TextField field2;
    TextField field3;
    TextField field4;
    TextField field5;
    TextField field6;
    Checkbox field7;

    // The names of the recordset fields
    Variant name1;
    Variant name2;
    Variant name3;
    Variant name4;
    Variant name5;
    Variant name6;
    Variant name7;

    // Create the form
    SimpleForm(Recordset r)
    {
        // Set the recordset
        m_recordset = r;

        // Create panels for the labels and fields
        Panel labels = new Panel();
        Panel fields = new Panel();

        // Set those panels as a grid, one column wide
        labels.setLayout(new GridLayout(0, 1));
        fields.setLayout(new GridLayout(0, 1));

        // Set the form as labels to the left, fields to the right
        setLayout(new FlowLayout());
        add(labels);
        add(fields);

        // Set the first label and field
        //    Create the label and add it into the form
        labels.add(new Label("Full Name"));
        //    Create the field and add it into the form
        fields.add(field1 = new TextField(25));
        //    Disable the field since the access is read-only
        field1.disable();
        //    Create the field name for use with getItem
        name1 = new Variant();
        name1.putString("Name");

        // Repeat for the other labels and fields
        labels.add(new Label("E-Mail Name"));
        fields.add(field2 = new TextField(10));
        field2.disable();
        name2 = new Variant();
        name2.putString("Email");

        labels.add(new Label("Phone Extension"));
        fields.add(field3 = new TextField(12));
        field3.disable();
        name3 = new Variant();
        name3.putString("Phone");

        labels.add(new Label("Office Location"));
        fields.add(field4 = new TextField(15));
        field4.disable();
        name4 = new Variant();
        name4.putString("Location");

        labels.add(new Label("Manager"));
        fields.add(field5 = new TextField(10));
        field5.disable();
        name5 = new Variant();
        name5.putString("Manager");

        labels.add(new Label("Date of Hire"));
        fields.add(field6 = new TextField(10));
        field6.disable();
        name6 = new Variant();
        name6.putString("HireDate");

        labels.add(new Label("Certified"));
        fields.add(field7 = new Checkbox());
        field7.disable();
        name7 = new Variant();
        name7.putString("Certified");
    }

    // Show the data in the form
    void showData()
    {
        // Get the fields in the recordset
        Fields fields = m_recordset.getFields();
        _Field f;

        // Create a Variant to get the value of each field
        Variant value;

        // Get the first field
        f = fields.getItem(name1);
        // Get its value
        value = f.getValue();
        // Set the field in the form
        field1.setText(value.toString());

        // Repeat for the other fields
        f = fields.getItem(name2);
        value = f.getValue();
        field2.setText(value.toString());

        f = fields.getItem(name3);
        value = f.getValue();
        field3.setText(value.toString());

        f = fields.getItem(name4);
        value = f.getValue();
        field4.setText(value.toString());

        f = fields.getItem(name5);
        value = f.getValue();
        field5.setText(value.toString());

        f = fields.getItem(name6);
        value = f.getValue();
        field6.setText(value.toString());

        f = fields.getItem(name7);
        value = f.getValue();
        field7.setState(value.getBoolean());
    }
}

//==============================================================================
// Main Class for applet simpledao
//
//==============================================================================
public class simpledao extends Applet
{
    // Toolbar
    Panel m_toolbar;
    Button m_first;
    Button m_prev;
    Button m_next;
    Button m_last;

    // Data Entry Form
    SimpleForm m_form;
    Recordset recordset;
    String filename;

    // STANDALONE APPLICATION SUPPORT:
    //        m_fStandAlone will be set to true if applet is run standalone
    //--------------------------------------------------------------------------
    boolean m_fStandAlone = false;

    // PARAMETER SUPPORT:
    //        Parameters allow an HTML author to pass information to the applet;
    // the HTML author specifies them using the <PARAM> tag within the <APPLET>
    // tag.  The following variables are used to store the values of the
    // parameters.
    //--------------------------------------------------------------------------

    // Members for applet parameters
    // <type>       <MemberVar>    = <Default Value>
    //--------------------------------------------------------------------------
    private String m_Database = "Sample Database.mdb";
    private String m_Recordset = "Employees";

    // Parameter names.  To change a name of a parameter, you need only make
    // a single change.  Simply modify the value of the parameter string below.
    //--------------------------------------------------------------------------
    private final String PARAM_Database = "Database";
    private final String PARAM_Recordset = "Recordset";

    // STANDALONE APPLICATION SUPPORT
    //     The GetParameter() method is a replacement for the getParameter() method
    // defined by Applet. This method returns the value of the specified parameter;
    // unlike the original getParameter() method, this method works when the applet
    // is run as a standalone application, as well as when run within an HTML page.
    // This method is called by GetParameters().
    //---------------------------------------------------------------------------
    String GetParameter(String strName, String args[])
    {
        if (args == null)
        {
            // Running within an HTML page, so call original getParameter().
            //-------------------------------------------------------------------
            return getParameter(strName);
        }

        // Running as standalone application, so parameter values are obtained from
        // the command line. The user specifies them as follows:
        //
        //    JView simpledao param1=<val> param2=<"val with spaces"> ...
        //-----------------------------------------------------------------------
        int    i;
        String strArg    = strName + "=";
        String strValue = null;

        for (i = 0; i < args.length; i++)
        {
            if (strArg.equalsIgnoreCase(args[i].substring(0, strArg.length())))
            {
                // Found matching parameter on command line, so extract its value.
                // If in double quotes, remove the quotes.
                //---------------------------------------------------------------
                strValue= args[i].substring(strArg.length());
                if (strValue.startsWith("\""))
                {
                    strValue = strValue.substring(1);
                    if (strValue.endsWith("\""))
                        strValue = strValue.substring(0, strValue.length() - 1);
                }
            }
        }

        return strValue;
    }

    // STANDALONE APPLICATION SUPPORT
    //     The GetParameters() method retrieves the values of each of the applet's
    // parameters and stores them in variables. This method works both when the
    // applet is run as a standalone application and when it's run within an HTML
    // page.  When the applet is run as a standalone application, this method is
    // called by the main() method, which passes it the command-line arguments.
    // When the applet is run within an HTML page, this method is called by the
    // init() method with args == null.
    //---------------------------------------------------------------------------
    void GetParameters(String args[])
    {
        // Query values of all Parameters
        //--------------------------------------------------------------
        String param;

        // Database: Parameter description
        //--------------------------------------------------------------
        param = GetParameter(PARAM_Database, args);
        if (param != null)
            m_Database = param;

        // Recordset: Parameter description
        //--------------------------------------------------------------
        param = GetParameter(PARAM_Recordset, args);
        if (param != null)
            m_Recordset = param;

    }

    // STANDALONE APPLICATION SUPPORT
    //     The main() method acts as the applet's entry point when it is run
    // as a standalone application. It is ignored if the applet is run from
    // within an HTML page.
    //--------------------------------------------------------------------------
    public static void main(String args[])
    {
        // Create Toplevel Window to contain applet simpledao
        //----------------------------------------------------------------------
        simpledaoframe frame = new simpledaoframe("simpledao");

        // Must show Frame before we size it so insets() will return valid values
        //----------------------------------------------------------------------
        frame.show();
        frame.hide();
        frame.resize(frame.insets().left + frame.insets().right  + 320,
                     frame.insets().top  + frame.insets().bottom + 240);

        // The following code starts the applet running within the frame window.
        // It also calls GetParameters() to retrieve parameter values from the
        // command line, and sets m_fStandAlone to true to prevent init() from
        // trying to get them from the HTML page.
        //----------------------------------------------------------------------
        simpledao applet_simpledao = new simpledao();

        frame.add("Center", applet_simpledao);
        applet_simpledao.m_fStandAlone = true;
        applet_simpledao.GetParameters(args);
        applet_simpledao.init();
        applet_simpledao.start();
        frame.show();
    }

    // simpledao Class Constructor
    //--------------------------------------------------------------------------
    public simpledao()
    {
        // Create the toolbar and add it to the applet
        m_toolbar = new Panel();
        add("North", m_toolbar);
        m_toolbar.add(m_first = new Button("First"));
        m_toolbar.add(m_prev = new Button("Prev"));
        m_toolbar.add(m_next = new Button("Next"));
        m_toolbar.add(m_last = new Button("Last"));
    }

    // APPLET INFO SUPPORT:
    //        The getAppletInfo() method returns a string describing the applet's
    // author, copyright date, or miscellaneous information.
    //--------------------------------------------------------------------------
    public String getAppletInfo()
    {
        return "Name: simpledao\r\n" +
               "Author: Dan Jinguji\r\n" +
               "Created with Microsoft Visual J++ Version 1.0";
    }

    // PARAMETER SUPPORT
    //        The getParameterInfo() method returns an array of strings describing
    // the parameters understood by this applet.
    //
    // simpledao Parameter Information:
    //  { "Name", "Type", "Description" },
    //--------------------------------------------------------------------------
    public String[][] getParameterInfo()
    {
        String[][] info =
        {
            { PARAM_Database, "String", "Name of the Database" },
            { PARAM_Recordset, "String", "Name of the Recordset" },
        };
        return info;
    }

    // The init() method is called by the AWT when an applet is first loaded or
    // reloaded.  Override this method to perform whatever initialization your
    // applet needs, such as initializing data structures, loading images or
    // fonts, creating frame windows, setting the layout manager, or adding UI
    // components.
    //--------------------------------------------------------------------------
    public void init()
    {
        if (!m_fStandAlone)
            GetParameters(null);
        // If you use a ResourceWizard-generated "control creator" class to
        // arrange controls in your applet, you may want to call its
        // CreateControls() method from within this method. Remove the following
        // call to resize() before adding the call to CreateControls();
        // CreateControls() does its own resizing.
        //----------------------------------------------------------------------
        resize(320, 200);

        // Set the name of the database (parameter)
        if (m_fStandAlone)
            // use the value on the command line for the MDB filename
            filename = m_Database;
        else
        try {
            // otherwise generate it relative to the applet
            java.net.URL fn;
            fn = new java.net.URL(getDocumentBase(), m_Database);
            // strip away the "file:/" from the URL
            filename = fn.getFile().substring(1);
        } catch(Exception e) {
            showStatus("Error: " + e.getMessage());
        }
    }

    // Place additional applet clean up code here.  destroy() is called when
    // when you applet is terminating and being unloaded.
    //-------------------------------------------------------------------------
    public void destroy()
    {
    }

    // simpledao Paint Handler
    //--------------------------------------------------------------------------
    public void paint(Graphics g)
    {
    }

    //        The start() method is called when the page containing the applet
    // first appears on the screen. The AppletWizard's initial implementation
    // of this method starts execution of the applet's thread.
    //--------------------------------------------------------------------------
    public void start()
    {
        // Create the database engine using the license key
        _DBEngine idbengine = dao_dbengine.create();
        Database database;

        // Create Variants for optional parameters
        Variant v1 = new Variant();
        Variant v2 = new Variant();
        Variant v3 = new Variant();

        v1.putBoolean(false);
        v2.putBoolean(false);
        v3.putString("");

        // Open the database for non-exclusive access
        database = idbengine.OpenDatabase(filename, v1, v2, v3);

        // Create Variants for optional parameters
        Variant v4 = new Variant();
        Variant v5 = new Variant();

        v4.putShort(Constants.dbOpenDynaset);
        v5.putShort(Constants.dbReadOnly);

        // Create the recordset, a read-only dynaset
        recordset = database.OpenRecordset(m_Recordset, v4, v5);

        // Create the form, passing it the recordset
        m_form = new SimpleForm(recordset);

        // Add it to the applet
        add("Center", m_form);

        // Get the first record in the recordset
        recordset.MoveFirst();

        // Display that record
        m_form.showData();

    }

    //        The stop() method is called when the page containing the applet is
    // no longer on the screen. The AppletWizard's initial implementation of
    // this method stops execution of the applet's thread.
    //--------------------------------------------------------------------------
    public void stop()
    {
        // Close the recordset
        recordset.Close();
        recordset = null;

        // Remove the form
        remove(m_form);
        m_form = null;
    }


    public boolean action(Event  evt, Object  what)
    {
        // Handle click on the First button
        if (evt.target == m_first)
        {
            // Update the status bar, if available
            if (! m_fStandAlone) showStatus ("Getting first record");

            // Move to the requested record
            recordset.MoveFirst();

            // Show that record
            m_form.showData();

            // Event handled
            return true;
        }

        // Handle click on the Prev button
        if (evt.target == m_prev)
        {
            // Update the status bar, if available
            if (! m_fStandAlone) showStatus ("Getting previous record");

            // Move to the requested record
            recordset.MovePrevious();

            // Show that record
            m_form.showData();

            // Event handled
            return true;
        }

        // Handle click on the Next button
        if (evt.target == m_next)
        {
            // Update the status bar, if available
            if (! m_fStandAlone) showStatus ("Getting next record");

            // Move to the requested record
            recordset.MoveNext();

            // Show that record
            m_form.showData();

            // Event handled
            return true;
        }

        // Handle click on the Last button
        if (evt.target == m_last)
        {
            // Update the status bar, if available
            if (! m_fStandAlone) showStatus ("Getting last record");

            // Move to the requested record
            recordset.MoveLast();

            // Show that record
            m_form.showData();

            // Event handled
            return true;
        }

        // Event not handled
        return false;
    }

}