How to show error message to user as I want?

Question

Hello.
1)I write application for library in Java. I want to show down message to user as "Not this book in library"
integrity constraint (LIBRARY.BOOK_USER_B_FK) violated - parent key not found
2) Can I change message text for user ? If can, how?
Thanks

Answer 1

String query = insert into book_user user_id, book_id , out_date, in_date values( 2011005 , 123456 , to_date('14.4.2011','dd.mm.yyyy') , to_date('14.4.2011','dd.mm.yyyy') )
k = insert.update(query);
if(k == 0){
JOptionPane.showMessageDialog(this,Errors.getError1() ,"Book", WIDTH);
}else{
JOptionPane.showMessageDialog(this, k + " it is ok" ,"Book", WIDTH);
*public class Errors {*
private static String error1;
*public static String getError1() {*
return error1;
*public static void setError1(String error1) {*
Errors.error1 = error1;
public int update(String query) {
try {
ods = new OracleDataSource();
ods.setURL(read.readUrl());
ods.setUser(Common.getUser());
ods.setPassword(Common.getPassword());
conn = ods.getConnection();
stmt = conn.createStatement();
a = stmt.executeUpdate(query);
conn.commit();
conn.close();
} catch (SQLException e) {
System.out.println("excetion_update + " + e.getMessage());
Errors.setError1(e.getLocalizedMessage());
catch (IOException w){
w.getMessage();
return a;
I am new to Java, sorry this codes:((
Thanks