import java.awt.*;
import java.awt.event.*;

import java.applet.*;

import com.sun.java.swing.table.*;
import com.sun.java.swing.event.*;
import com.sun.java.swing.*;

import java.util.*;


import java.sql.*;
import oracle.jdbc.driver.OracleDriver.*;
import oracle.jdbc.driver.*;

public class TableViewer extends JApplet {

    //UI-Components
    JTable table = new JTable();
    //JPanel panel = new JPanel();
    Box prompt = new Box(BoxLayout.X_AXIS);
    JLabel selectLabel = new JLabel("Select");
    JLabel fromLabel = new JLabel("from");
    JTextField colField = new JTextField("*",10);
    JTextField tableField = new JTextField(20);
    JLabel whereLabel = new JLabel("where:");
    JTextField whereField = new JTextField(40);
    JDesktopPane desktop = new JDesktopPane();
    
    // Data-Holding for TableModel
    Hashtable tableData = new Hashtable();
    Object[][] data = null;
    String[] headers = null;
    DataTable dt;

    // JDBC-Variables
    String driverClass =  "oracle.jdbc.driver.OracleDriver";
    Connection conn = null;
    String connectStr = "jdbc:oracle:thin:@waldorf.uni-muenster.de:1521:ifgi";
    String user = "laber";
    String password = "blablabla";
    String sqlStatement;
    
    public void init(){
	
	//UI Initialization
	getContentPane().setLayout(new BorderLayout());
	prompt.add(selectLabel);
	prompt.add(Box.createHorizontalStrut(8));
	prompt.add(colField);
	prompt.add(Box.createHorizontalStrut(8));
	prompt.add(fromLabel);
	prompt.add(Box.createHorizontalStrut(8));
	prompt.add(tableField);
	prompt.add(Box.createHorizontalStrut(8));
	prompt.add(whereLabel);
	prompt.add(Box.createHorizontalStrut(8));
	prompt.add(whereField);


	getContentPane().add(desktop, BorderLayout.CENTER);
	getContentPane().add(prompt, BorderLayout.SOUTH);


	//Controller Initialization
	ActionListener ctrl =  new ActionListener() {
	    public void actionPerformed(ActionEvent e) {
		fetchTableData(tableField.getText());
	    }};
    

	tableField.addActionListener(ctrl);
	whereField.addActionListener(ctrl);
	colField.addActionListener(ctrl);

	//DB Initialization
	try {
	DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());
	System.out.println ("  Connecting to " + connectStr + "...");
	
	conn = DriverManager.getConnection (connectStr, user, password);
	
	System.out.println("Done.");
	((OracleConnection)conn).setDefaultRowPrefetch (50);
	DatabaseMetaData dma = conn.getMetaData ();

	System.out.println("Connected to " + dma.getURL());
	System.out.println("Driver       " + dma.getDriverName());
	System.out.println("Version      " + dma.getDriverVersion());
	} catch (Exception e) {System.err.println("Exception: "+e);
	e.printStackTrace();}
    }

    
    void fetchTableData(String tableName){
	System.out.println("Fetching Data from Table: "+tableName+"!");
	
	try {
	Statement s = conn.createStatement();
	ResultSet r = null;
	String whereClause = whereField.getText();
	String cols = colField.getText();
	System.out.println("wherefield: <"+whereClause+">");
	r = s.executeQuery("SELECT COUNT(1) FROM " + tableName 
             + (whereClause.length() > 0 ? " WHERE " + whereClause : "" ));
	r.next();
	int count = r.getInt(1);
	r.close();
	r = s.executeQuery("SELECT " + cols + " FROM " 
             + tableName + (whereClause.length() > 0 ? " WHERE " 
             + whereClause : "" ));
	System.out.println("Done.");
	ResultSetMetaData md = r.getMetaData();
	int width = md.getColumnCount();


	System.out.println("Transferring Data to TableModel ...");

	// headers contain name and type of column
	headers = new String[width];
	for(int i=1; i <= width; i++)
	    headers[i-1] = new String(md.getColumnName(i));
	// headers[i-1] = new String(md.getColumnName(i)+" ("+md.getColumnTypeName(i)+")");
	

	// fill in Data
	data = new Object[count][width];
	for(int i=0; i < count; i++){
	    r.next();
	    for(int j=1; j <= width; j++)
		data[i][j-1] = r.getObject(j);
	}

	System.out.println("Displaying Data ...");

	/*	if(dt != null)
	    this.getContentPane().remove(dt);
	else
	    this.getContentPane().remove(tablelabel);
	*/
	dt = new DataTable(headers, data);
	dt.setSize(800,600);
	JInternalFrame fr = new JInternalFrame(" "+cols+" from "+tableName
		      +(whereClause.length() > 0 ? " WHERE " + whereClause 
                        : "" )+ " ("+count+" Entries)", true, true, true,true);
	fr.getContentPane().add(dt);
	fr.pack();
	desktop.add(fr, new Integer(1));
	fr.moveToFront();
	fr.setMaximum(true);
	this.repaint();
	this.validateTree();
	
	} catch(Exception e) {System.err.println("Exception: "+e);
	e.printStackTrace();}
    }
    

    public static void main(String[] args){
	TableViewer tt = new TableViewer();
	JFrame frame = new JFrame("TableViewer");
	frame.addWindowListener(new WindowAdapter() {
	    public void windowClosing(WindowEvent e){
		System.exit(0);
	     }
	});
	frame.getContentPane().add(tt,BorderLayout.CENTER);
	frame.setSize(800,600);
	frame.setVisible(true);
	tt.init();
	tt.start();
    }
}

class DataTable extends JPanel {
    

     DataTable (final String[] headers, final Object[][] data) {
	 
	 // needed for automatic resizing 
	 setLayout(new GridLayout(1,1));

	 AbstractTableModel model = new AbstractTableModel (){
	    
	    public Object getValueAt(int row, int col){
		try {
		    return data[row][col];
		} catch (Exception e) {
		    System.out.println("Row "+row+" Col: "+col);
		}
		return "ERROR";
	    }
	    
	    public int getRowCount(){
		return data.length;
	    }

	    public int getColumnCount(){
		return headers.length;
	    }

	    public String getColumnName(int col){
		return headers[col];
	    }
	    
	};
	
	JTable t = new JTable(model);
	t.setAutoResizeMode(JTable.AUTO_RESIZE_ALL_COLUMNS);
	JScrollPane s = new JScrollPane(t);
	this.add(s);
	System.out.println("Done with initialization");
	
	
     }

}