Accessing Databases Using JDBC - Java Programming: Comprehensive Concepts and Techniques - page 738

309 // get a stock description from the Stocks table

310 public String getStockDesc ( String stockSymbol )

311 throws SQLException , IOException , ClassNotFoundException

312 {

313 Statement stmt = con.createStatement () ;

314 String stockDesc = null ;

315
316 ResultSet rs = stmt.executeQuery ( "SELECT symbol, name FROM Stocks "

317 + "WHERE symbol = '" +stockSymbol+ "'" ) ;

318 if ( rs.next ())

319 stockDesc = rs.getString ( "name" ) ;

320 rs.close () ;

321 stmt.close () ;

322
323 return stockDesc;

324 }

325
326
327 // Methods to access a complete record

328
329 // get User data from the Users table

330 public User getUser ( String userID ) throws SQLException , IOException ,

331 ClassNotFoundException

332 {

333 Statement stmt = con.createStatement () ;

334
335 String dbUserID;

336 String dbLastName;

337 String dbFirstName;

338 Password dbPswd;

339 boolean isAdmin;

340
341 byte [] buf = null ;

342 User user = null ;

343 ResultSet rs = stmt.executeQuery ( "SELECT * FROM Users WHERE userID = '"

344 +userID+ "'" ) ;

345 if ( rs.next ())

346 {

347 dbUserID = rs.getString ( "userID" ) ;

348 dbLastName = rs.getString ( "lastName" ) ;

349 dbFirstName = rs.getString ( "firstName" ) ;

350
351 // Do NOT use with JDK 1.2.2 using JDBC-ODBC bridge as

352 // SQL NULL data value is not handled correctly.

353 buf = rs.getBytes ( "pswd" ) ;

354 dbPswd= ( Password ) deserializeObj ( buf ) ;

355
356 isAdmin = rs.getBoolean ( "admin" ) ;

357 user = new User ( dbUserID,dbFirstName,dbLastName,dbPswd,isAdmin ) ;

358 }

359 rs.close () ;

360 stmt.close () ;

361
362 return user; // User object created for userID

363 }

364
365
366 // Methods to access a list of records

367
368 // get list of selected fields for all records from the Users Table

369 public ArrayList listUsers () throws SQLException , IOException ,

370 ClassNotFoundException

371 {

372 ArrayList aList = new ArrayList () ;

373 Statement stmt = con.createStatement () ;

374
375 ResultSet rs = stmt.executeQuery ( "SELECT userID, firstName, lastName, admin "

376 + "FROM Users ORDER BY userID" ) ;

377

FIGURE 11-36