Java Simple link Oracle database registration and login function of the implementation code _java

Copy Code code as follows:

Basic information for user users and 3 columns in the UserInfo table
Package landing judgment;

public class User {

private String name;
Private String LoginName;
Private String LOGINPSW;
Public String GetName () {
return name;
}
public void SetName (String name) {
THIS.name = name;
}
Public String Getloginname () {
return loginname;
}
public void Setloginname (String loginname) {
This.loginname = LoginName;
}
Public String GETLOGINPSW () {
return LOGINPSW;
}
public void Setloginpsw (String loginpsw) {
THIS.LOGINPSW = LOGINPSW;
}
}
Small blocks of code for registration and landing
Package landing judgment;

Import Java.util.Scanner;

public class in {

public static User GetUser () {
User U = new user ();
Scanner sc = new Scanner (system.in);
System.out.println ("Please enter login name");
U.setloginname (Sc.nextline ());
System.out.println ("Please enter the password");
U.SETLOGINPSW (Sc.nextline ());
return u;
}
public static User RegisterUser () {
User U = new user ();
Scanner sc = new Scanner (system.in);
SYSTEM.OUT.PRINTLN ("Please register user name");
U.setname (Sc.nextline ());
SYSTEM.OUT.PRINTLN ("Please register login name");
U.setloginname (Sc.nextline ());
SYSTEM.OUT.PRINTLN ("Please register password");
U.SETLOGINPSW (Sc.nextline ());
return u;
}
}

Check when landing, to determine whether the login name and password is correct, correct return username
Package landing judgment;

Import java.sql.Connection;
Import Java.sql.DriverManager;
Import java.sql.PreparedStatement;
Import Java.sql.ResultSet;
Import java.sql.SQLException;

public class Check {

public static void CheckUser (User u)
{
try {
Class.forName ("Oracle.jdbc.driver.OracleDriver");
catch (ClassNotFoundException e) {
E.printstacktrace ();
}
String url = "Jdbc:oracle:thin: @localhost: 1521:ORCL";
String user = "Scott";
String password = "Tiger";
Connection conn = null;
ResultSet rs = null;
PreparedStatement PST = NULL;

String sql = "SELECT name from USERINFO where LoginName =?" and LOGINPSW =? ";
try {
conn = drivermanager.getconnection (URL, user, password);
PST = conn.preparestatement (SQL);
Pst.setstring (1, U.getloginname ());
Pst.setstring (2,U.GETLOGINPSW ());
rs = Pst.executequery ();
while (Rs.next ()) {
U.setname (rs.getstring (1));
}
catch (SQLException e) {
E.printstacktrace ();
}finally{
try {
Rs.close ();
Pst.close ();
Conn.close ();
catch (SQLException e) {
E.printstacktrace ();
}
}
if (u.getname () = null | | u.getname (). IsEmpty ()) {
SYSTEM.OUT.PRINTLN ("Landing failure");
}else{
System.out.println ("Welcome" +u.getname () + "landing");
}

}
}

Registration interface, to determine whether the login has a duplicate, there is a duplication of registration failure. There's a little doubt that has been marked out with comments
Package landing judgment;

Import java.sql.Connection;
Import Java.sql.DriverManager;
Import java.sql.PreparedStatement;
Import Java.sql.ResultSet;
Import java.sql.SQLException;
Import java.sql.Statement;

public class Register {

public static void Registuser (User u) {

try {
Class.forName ("Oracle.jdbc.driver.OracleDriver");
catch (ClassNotFoundException e) {
E.printstacktrace ();
}
String url = "Jdbc:oracle:thin: @localhost: 1521:ORCL";
String user = "Scott";
String password = "Tiger";
Connection conn = null;
String sql = "Insert into USERINFO values (?,?,?)";
PreparedStatement PST = NULL;

Determine if the login name already exists
Statement s = null;
ResultSet rs = null;
String sql_ck = "Select LOGINNAME from USERINFO";
try {
conn = drivermanager.getconnection (URL, user, password);
PST = conn.preparestatement (SQL);
Pst.setstring (1, U.getname ());
Pst.setstring (2, U.getloginname ());
Pst.setstring (3, U.GETLOGINPSW ());
Determine if the login name already exists
s = conn.createstatement ();
rs = S.executequery (SQL_CK);
while (Rs.next ()) {//Why rs.getstring (2) prompts an invalid index?
if (rs.getstring ("LOGINNAME"). Equals (U.getloginname ())) {
SYSTEM.OUT.PRINTLN ("Login name already exists, registration failed");
Break
}else{
Pst.executeupdate ();
SYSTEM.OUT.PRINTLN ("registered success");
Break
}
}
catch (SQLException e) {
E.printstacktrace ();
}finally{
try {
Rs.close ();
Pst.close ();
S.close ();
Conn.close ();
catch (SQLException e) {
E.printstacktrace ();
}
}


}
}
Main interface//
The structure of the table in the database so
Name (user name, for display),
LoginName (login name, ID entered at login)
LOGINPSW (password entered at login)
Package landing judgment;

Import Java.util.Scanner;

public class Test {

public static void Main (string[] args) {

int chos = 0;
Scanner sc = new Scanner (system.in);
SYSTEM.OUT.PRINTLN ("\t\t login please press the 1\t\t register please press 2");
Chos = Sc.nextint ();
Switch (chos) {
Case 1:check.checkuser (In.getuser ());
Case 2:register.registuser (In.registeruser ());
Default:System.out.println ("Please enter the right choice");
}
}

}