fatti una classe a parte e chiamala Database.java dove metti tutti i metodi di connessione,disconnessione ecc.....e poi ti richiami questi metodi dalla tua classe di lavoro che stai utilizzando

Mo ti posto una classe Database che uso io.......

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class Database {

private static final String driver = "org.gjt.mm.mysql.Driver";
private String url = "jdbc:mysql://localhost:3306/Speaker?autoReconnect=true";
private static final String username = "root";
private static final String password = "admin";
private Connection dbConnection = null;



public Database() {
if(dbConnection == null) {
try {
Class.forName(driver).newInstance();
dbConnection = DriverManager.getConnection(url, username, password);
dbConnection.setAutoCommit(true);
} catch (Exception ex) {
System.out.println("Failed to register MySQL Connector/J");
return;
}

}
}

public Database(String host) {
url = "jdbc:mysql://" + host + "/emasdb?autoReconnect=true";
if(dbConnection == null) {
try {
Class.forName(driver).newInstance();
dbConnection = DriverManager.getConnection(url, username, password);
dbConnection.setAutoCommit(true);
} catch (Exception ex) {
System.out.println("Failed to register MySQL Connector/J");
return;
}

}
}

public void changeHost(String host) {
url = "jdbc:mysql://" + host + "/emasdb?autoReconnect=true";
}



public ResultSet executeQuery(String sqlString) throws Exception {
if(dbConnection != null) {
if(!(dbConnection.isClosed())) {
Statement stmt = dbConnection.createStatement();
return stmt.executeQuery(sqlString);
}
else {
dbConnection = null;
dbConnection = DriverManager.getConnection(url, username, password);
dbConnection.setAutoCommit(true);
Statement stmt = dbConnection.createStatement();
return stmt.executeQuery(sqlString);
}
}
else {
Class.forName(driver).newInstance();
dbConnection = DriverManager.getConnection(url, username, password);
dbConnection.setAutoCommit(true);
Statement stmt = dbConnection.createStatement();
return stmt.executeQuery(sqlString);
}
}

public int executeOperation(String sqlString) throws Exception {
if(dbConnection != null) {
if(!(dbConnection.isClosed())) {
Statement stmt = dbConnection.createStatement();
int tResult = stmt.executeUpdate(sqlString);
stmt.close();
return tResult;
}
else {
dbConnection = null;
dbConnection = DriverManager.getConnection(url, username, password);
dbConnection.setAutoCommit(true);
Statement stmt = dbConnection.createStatement();
int tResult = stmt.executeUpdate(sqlString);
stmt.close();
return tResult;
}
}
else {
Class.forName(driver).newInstance();
dbConnection = DriverManager.getConnection(url, username, password);
dbConnection.setAutoCommit(true);
Statement stmt = dbConnection.createStatement();
int tResult = stmt.executeUpdate(sqlString);
stmt.close();
return tResult;
}
}

public void disconnect() throws SQLException {
dbConnection.close();
dbConnection = null;
return;
}
}

Cambia i parametri in alto con i tuoi.....dovrebbe andare....almeno a me va