Java connect to mysql

Question

hi,im new user here.....im also a new java user.......i've just learn how to connect java with mysql,so i download the driver MySQL Connector/J 5.0
after that,i mport the library to JBulider X.then i got error with my script.
package database;
import java.sql.*;
public class Mysql {
public static void main(String[] args) {
Connection con = null;
Statement stmt = null;
ResultSet rs = null;
try {
Class.forName("com.mysql.jdbc.Driver").newInstance();
catch (Exception e){
System.err.println("Error Loading driver :" + e.getMessage());
and then the error are :
java.lang.NoClassDefFoundError: org/aspectj/lang/Signature
     at java.lang.Class.forName0(Native Method)
     at java.lang.Class.forName(Class.java:141)
     at database.Mysql.main(Mysql.java:19)
Exception in thread "main"
What is that meant ?please someone help me...i need a quick reply......thanxxxsss....

Answer 1

hello,all.........i just connected to the driver,but now another error come out
Error SQL Communications link failure due to underlying exception:
** BEGIN NESTED EXCEPTION **
java.net.SocketException
MESSAGE: java.net.ConnectException: Connection refused: connect
STACKTRACE:
java.net.SocketException: java.net.ConnectException: Connection refused: connect
     at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:156)
     at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:276)
     at com.mysql.jdbc.Connection.createNewIO(Connection.java:2592)
     at com.mysql.jdbc.Connection.<init>(Connection.java:1509)
     at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:266)
     at java.sql.DriverManager.getConnection(DriverManager.java:512)
     at java.sql.DriverManager.getConnection(DriverManager.java:193)
     at database.Mysql.main(Mysql.java:28)
** END NESTED EXCEPTION **
wat is that mean ?
this is my script
package database;
import java.sql.*;
public class Mysql {
public static void main(String[] args) {
Connection con = null;
Statement stmt = null;
ResultSet rs = null;
try {
System.out.println("Loading drivers........");
Class.forName("com.mysql.jdbc.Driver").newInstance();
System.out.println("Driver loaded !");
catch (Exception e){
System.err.println("Error Loading driver :" + e.getMessage());
try {
con = DriverManager.getConnection("jdbc:mysql://localhost/test_db?user=test_admin&password=1234");
stmt = con.createStatement();
rs = stmt.executeQuery("select * from `stock`");
ResultSetMetaData rsmd = rs.getMetaData();
int nColumn = rsmd.getColumnCount();
for(int i=1;i<=nColumn;i++){
System.out.print(rsmd.getColumnName(i) + " | ");
System.out.print("\n");
/*while(rs.next()){
System.out.println(rs.getLong(1) + "\t" + rs.getString(2) + "\t" + rs.getLong(3) + "\t" + rs.getString(4) + "\t"
+ rs.getDouble("price") + "\t" + rs.getInt("supplier") + "\t" + rs.getDate("buy_date"));
rs.close();
stmt.close();
con.close();
catch (SQLException e){
System.err.println("Error SQL " + e.getMessage());