Java and MySQL database connection, and implementation of ADD, delete, modify, query

UserAccount class:

public class UserAccount {
Private String account;//Account card number
Private String uname;//Name
Private String upwd;//Password
private double balance;//Balance

//Construction method
Public UserAccount (String account, String uname, String upwd, double balance) {
Super ();
This.account = account;
This.uname = uname;
This.upwd = upwd;
This.balance = balance;
}
Public String Getaccount () {
return account;
}
public void Setaccount (String account) {
This.account = account;
}
Public String Getuname () {
return uname;
}
public void Setuname (String uname) {
This.uname = uname;
}
Public String getupwd () {
return upwd;
}
public void Setupwd (String upwd) {
This.upwd = upwd;
}
Public double getbalance () {
return balance;
}
public void setbalance (double balance) {
This.balance = balance;
}

import java.sql.Connection;
import Java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import Java.util.Calendar;
import java.util.List;
import Java.util.Scanner;

public class Mysqlconnect {
private static final String driver= "Com.mysql.jdbc.Driver";
private static final String url= "Jdbc:mysql://localhost:3306/bank";
private static final String user= "root";
private static final String pwd= "root";
Static Connection Conn=null; //Link Object
Static Statement St=null; //Operation
Static PreparedStatement Ps=null;
Static ResultSet Rs=null; //Result set

Connecting Database encapsulation
public static void Getconnection () {
try {
Class.forName (DRIVER);
Conn =drivermanager.getconnection (URL, USER, PWD);
} catch (ClassNotFoundException e) {
E.printstacktrace ();
} catch (SQLException e) {
E.printstacktrace ();
}
}

Close Resource
public static void CloseAll () {
try {
if (rs!=null)
Rs.close ();
if (st!=null)
St.close ();
} catch (SQLException e) {
E.printstacktrace ();
}
}

//Querying data in all databases
public static list<useraccount>getallusers () {
List<useraccount>list=new arraylist<useraccount> ();
try {
　　 //Get Connected
Getconnection ();
　　 //Build SQL statements
String sql = "Select account,uname,upassword,balance from UserAccount";
//Create statement Object
st = Conn.createstatement ();
　　 //Execute SQL statement
Rs=st.executequery (SQL);
//Processing result set
while (Rs.next ()) {
UserAccount user=new UserAccount (rs.getstring (1), rs.getstring (2), rs.getstring (3), rs.getdouble (4));
List.add (user);
}
} catch (SQLException e) {
E.printstacktrace ();
}finally{
CloseAll ();
}
return list;
}
//delete data from the database (directly deleted via account)
public static int Deleteuseraccount (String user) {
try {
　　 //Get Connected
Getconnection ();
　　 //Build SQL statements
String sql= "Delete from UserAccount where account=?";
　　 //Build stated Objects
Ps=conn.preparestatement (SQL);
Ps.setstring (1, user);
return Ps.executeupdate ();
}catch (SQLException e) {
E.printstacktrace ();
}finally{
CloseAll ();
}
return-1;
}
//Increase data in the database
public static int Adduseraccount (UserAccount user) {
try {
//Get Connected
Getconnection ();
//Build SQL statements
String sql= "INSERT into UserAccount (account,uname,upassword,balance) VALUES (?,?,?,?)";
　　 //Build stated Objects
Ps=conn.preparestatement (SQL);
Ps.setstring (1, User.getaccount ());
Ps.setstring (2, User.getuname ());
Ps.setstring (3, User.getupwd ());
Ps.setdouble (4, User.getbalance ());
return Ps.executeupdate ();
}catch (SQLException e) {
E.printstacktrace ();
}finally{
CloseAll ();
}
return-1;
}
//Modify data in the database
public static int updateuserbypstmt (UserAccount user) {
try {
　　 //Get Connected
Getconnection ();
　　 //Build SQL statements
String sql= "Update useraccount set uname=?,upassword=? where account=? ";
　　 //Build stated Objects
Ps=conn.preparestatement (SQL);
Ps.setstring (1, User.getuname ());
Ps.setstring (2, User.getupwd ());
Ps.setstring (3, User.getaccount ());
return Ps.executeupdate ();
}catch (SQLException e) {
E.printstacktrace ();
}finally{
CloseAll ();
}
return-1;
}

Check MySQL database single data by account
public static UserAccount Getuserbyaccount (String account) {
UserAccount User=null;
try{
Getconnection ();
String sql= "Select Account,uname,upassword,balance from UserAccount where account= '" +account+ "'";
St=conn.createstatement ();
Rs=st.executequery (SQL);
if (Rs.next ()) {
User=new UserAccount (rs.getstring (1), rs.getstring (2), rs.getstring (3), rs.getdouble (4));
}
}catch (Exception e) {
}finally{
CloseAll ();
}
return user;
}

Java and MySQL database connection, and implementation of ADD, delete, modify, query