JAVA如何抓取Oracle的unique错？

try{
.....
}catch(SQLException e){
if (e.getMessage().toLowerCase().indexOf("unique")<>-1){
/*处理unique错*/
}
}

public static final int getNextID(Connection con, String seqName) {
int id = 0;
try {
ResultSet rs = con.createStatement().executeQuery("select " + seqName + ".nextval from dual");
if (rs.next())
id = rs.getInt(1);
} catch (SQLException e) {}
return id;
}