Swing Interfaces with Sorting and Searching - Java Programming: Comprehensive Concepts and Techniques - page 469

first task of the search() method, in lines 289 through 293, is to clear the
JTextPane and display the headings as it did in the addTextToTextPane() method.

285 public void search ( String searchField, String searchArray [])

286 {

287 try

288 {

289 Document doc = textPane.getDocument () ; //assign text to document object

290 doc.remove ( 0,doc.getLength ()) ; //clear previous text

291
292

//display column titles

293 doc.insertString ( 0, "TITLE\tSTUDIO\tYEAR\n" ,textPane.getStyle ( "large" )) ;

294
295 //prompt user for search data

296 String search = JOptionPane.showInputDialog ( null , "Please enter the " +

searchField ) ;

297 boolean found = false ;

298
299

//search arrays

300 for ( int i = 0; i<title.length; i++ )

301 {

302 if ( search.compareTo ( searchArray [ i ]) ==0 )

303 {

304 doc.insertString ( doc.getLength () , title [ i ] + "\t" ,

textPane.getStyle ( "bold" )) ;

305 doc.insertString ( doc.getLength () , studio [ i ]

+ "\t" , textPane.getStyle ( "italic" )) ;

306 doc.insertString ( doc.getLength () , year [ i ] + "\n" ,

textPane.getStyle ( "regular" )) ;

found = true ;

307

308 }

309 }

310 if ( found == false )

311 {

312 JOptionPane.showMessageDialog ( null , "Your search produced no results." ,

"No results found" ,JOptionPane.INFORMATION_MESSAGE ) ;

313 sort ( title ) ;

314 }

315 }

316 catch ( BadLocationException ble )

317 {

318 System .err.println ( "Couldn't insert text." ) ;

319 }

320 }

321

FIGURE 7-34

Line 296 displays a JOptionPane input dialog box, which asks the user to
enter the search argument for the passed search field. A boolean flag named
found is set to false. The for() loop that begins in line 300 continues through the
entire array. Line 302 uses the compareTo() method to compare the search data
with the array member. If the method returns a 0, a match is found and inserted
in the Document, the flag is set to true (line 307), and the for() loop continues
evaluating the remaining elements in the array.
If the flag is not set to true, then a match was not found. Line 312 then dis-
plays a message dialog box, and the data displays sorted again, by title, in line
313. The code involved in inserting new information in the JTextPane Document
is placed inside a try block, as it was in the addTextToTextPane() method.