A Stock Trader - Developing Java Servlets - page 370

L ISTING 22.7 Continued

/*
implemented method from Service interface
*/
public void execute(HttpServletRequest request,
HttpServletResponse response,
ServletContext context) throws Exception {

// Get the symbol from the request
String symbol = request.getParameter(“symbol”);

if ( symbol == null ) {

throw
new Exception(“You must enter a stock symbol to query.”);

}

// Get a database connection from TRADER_POOL
ConnectionPool pool =
(ConnectionPool)context.getAttribute(“TRADER_POOL”);
Connection con = pool.getConnection();

try {

if ( con != null ) {

// Get the stock information from the database
Statement statement = con.createStatement();

StringBuffer query =
new StringBuffer(“SELECT * FROM STOCKS”);
query.append(“ WHERE SYMBOL = \'” + symbol + “\'”);

System.err.println(“Executing : “ + query.toString());

ResultSet rs =
statement.executeQuery(query.toString());

System.err.println(“Executed : “ + query.toString());

if ( rs.next() ) {

// Add the stock attribute to the request
request.setAttribute(“symbol”,
rs.getString(“symbol”));