/* Java Client for POS demo

/* from Zack Stewart, Spring 2003 CIS560

package sql_frontend;

import java.io.*;

import java.math.*;

import java.lang.*;

import java.util.*;

import java.sql.*;

import java.awt.*;

import javax.swing.*;

import javax.swing.event.*;

import java.awt.event.*;

public class POSFrame extends JFrame {

private String url = "jdbc:oracle:thin:@oracle.cis.ksu.edu:1521:ORACLE";

private String query = null;

private Connection oracle = null;

private Statement stmt = null;

private ResultSet result = null;

private Object[][] transactions = null,

customers = null,

inventory = null;

private Object[] columnNames = null;

private JTable inventoryTable = null,

custTable = null,

transTable = null;

/* standard GUI part … see screen snapshots

public POSFrame() {

try {

DriverManager.registerDriver(

new oracle.jdbc.driver.OracleDriver());

oracle = DriverManager.getConnection(url, “USER", "PASSWD");

stmt=oracle.createStatement();

transButton_actionPerformed(null);

invButton_actionPerformed(null);

query = "select * from customer";

result = stmt.executeQuery(query);

columnNames = getColumnNames(result);

customers = setToArray(result);

custTable = new JTable(customers, columnNames);

inventoryTable.setSelectionMode(

ListSelectionModel.SINGLE_SELECTION);

custTable.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);

jbInit();

}catch(Exception e) {

e.printStackTrace();

}

}

private void jbInit() throws Exception {

/* standard GUI inits

this.getContentPane().add(customerPane, null);

this.getContentPane().add(tablePane, null);

tablePane.getViewport().add(inventoryTable, null);

customerPane.getViewport().add(custTable, null);

}

public static void main(String[] args){new POSFrame();}

void this_windowClosing(WindowEvent e) {

try {

if(oracle != null)

oracle.close();

. . .

}

void buyButton_actionPerformed(ActionEvent e) {

if(!isInventoryOnscreen || inventoryTable.getSelectedRow() == -1 ||

custTable.getSelectedRow() == -1){ return; }

Object item = null;

int row = inventoryTable.getSelectedRow();

int customer = ((BigDecimal)customers[

custTable.getSelectedRow()][0]).intValue();

int quantity = Integer.parseInt(quanField.getText());

float total = quantity * ((BigDecimal)inventory[row][4]).floatValue();

int updated = 0;

int transaction = 0;

try{

item = inventory[row][0];

query = "select quantity from inventory where ID = " + item;

result = stmt.executeQuery(query);

result.next();

if(quantity > 0 && result.getInt(1) >= quantity){

query = "select max(id) from transaction";

result = stmt.executeQuery(query);

result.next();

transaction = result.getInt(1) + 1;

query = "update inventory . . .”;

stmt.executeUpdate(query);

query = "insert into transaction . . . ;

stmt.executeUpdate(query);

query = "insert into transactionitem . . . “ ;

stmt.executeUpdate(query);

query = "select quantity from inventory";

result = stmt.executeQuery(query);

for(int i = 0; result.next(); i++){

inventory[i][3] = result.getObject(1);

}

inventoryTable.tableChanged(new TableModelEvent(inventoryTable.getModel()));

}else{

JOptionPane.showMessageDialog(this,"Quantity to sell exceeds stock!");

}

}catch(Exception x){ x.printStackTrace();}

}

void invButton_actionPerformed(ActionEvent e) {

try{

query = "select * from inventory";

result = stmt.executeQuery(query);

columnNames = getColumnNames(result);

inventory = setToArray(result);

inventoryTable = new JTable(inventory, columnNames);

tablePane.getViewport().add(inventoryTable, null);

isInventoryOnscreen = true;

}catch(Exception x){ x.printStackTrace();}

}

void transButton_actionPerformed(ActionEvent e) {

/* similar , but longer

}

Object[][] setToArray(ResultSet s){

Vector data = new Vector();

Object[][] table = null;

int columns = 0 , rows = 0;

try{

columns = s.getMetaData().getColumnCount();

while(s.next()){

data.add(rows, new Vector());

for(int i = 0; i < columns; i++){

((Vector)data.get(rows)).add(i,s.getObject(i+1));

}

rows++;

}

table = new Object[rows][columns];

for(int i = 0; i < rows; i++){

for(int j = 0; j < columns; j++){

table[i][j] = ((Vector)data.get(i)).get(j);

}

}

}catch(Exception e){ e.printStackTrace(); }

return table;

}

Object[] getColumnNames(ResultSet s){

Vector names = new Vector();

int columns = 0;

try{

columns = s.getMetaData().getColumnCount();

for(int i = 0; i < columns; i++){

names.add(i,s.getMetaData().getColumnLabel(i+1));

}

}catch(Exception e){ e.printStackTrace(); }

return names.toArray();

}

}