Rock Paper Scissors programme

I have been frustrated with this code. The goal is to create a rock paper scissors game, best of 3. I have tried to make a "while" loop but I've got it all wrong and ended up scrapping it back to what I started with, a non-looping code.

If anyone can enlighten me how to make it loop until the computer or player gets a score of 3 wins, I would be so grateful!! Thank you so much
Sorry I should clarify, it needs to loop until the user or computer has 3 wins, so they rebattle until the user or computer reaches 3 wins

import java.util.Scanner;
import java.util.Random;
public class RockPaperScissors
{
public static void main(String[] args)
{
Scanner key;
Random randGen;
char userChoice, computerChoice;
int winner, compInt;
int computerScore;
int userScore;
int scoreCounter;
/***** INITIALIZATION SECTION *****/
key = new Scanner(System.in);
randGen = new Random();
userChoice = ' ';
computerChoice = ' ';
//winner = -1;
compInt = -1;
computerScore = 0;
userScore = 0;
scoreCounter = 0;
System.out.println("What is your name?");
String name = key.nextLine();
System.out.println(name + " play rock, paper, or scissors with me!!");
/***** INPUT SECTION *****/
System.out.println("Please enter R for rock, P for paper, or S for scissors:");
userChoice = key.next().toUpperCase().charAt(0);
//key.close();
/***** PROCESSING SECTION *****/
compInt=randGen.nextInt(3);
if (compInt == 0)
{
computerChoice = 'R';
}
else if (compInt == 1)
{
computerChoice = 'P';
}
else if (compInt == 2)
{
computerChoice = 'S';
}
winner = RockPaperScissors.decideWinner(userChoice,computerChoice);
/***** OUTPUT SECTION *****/
System.out.printf("Player: %c%nComputer: %c%n", userChoice, computerChoice);
switch (winner)
{
case 0:
System.out.println("It's a tie!");
System.out.println(name + ": " + userScore + ", Computer:" + computerScore );
break;
case 1:
System.out.println("You won!");
userScore++;
System.out.println(name + ": " + userScore + ", Computer:" + computerScore );
break;
case 2:
System.out.println("Computer won!");
computerScore++;
System.out.println(name + ": " + userScore + ", Computer:" + computerScore );
break;
default:
System.out.println("Invalid choice, try again.");
break;
}
//System.out.println("Thanks for playing!);
}
/***** STATIC METHODS *****/
/**Description: given two characters (R,P, or S) determines winner using rock
* paper rules. Assume input is valid and error checking is done in main
* programme. **/
public static int decideWinner(char p1,char p2)
{
String combo;
combo = String.format("%c%c", p1, p2);
switch(combo)
{
case "RS":
case "PR":
case "SP":
return 1;
case "RP":
case "PS":
case "SR":
return 2;
case "RR":
case "PP":
case "SS":
return 0;
}
return -1;
}
}
/***************************************************
while(userScore == 3)
{
System.out.println("You won the game" +name+ "! Congratulations");
scoreCounter++;
}
while(computerScore == 3)
{
System.out.println("Sorry " +name+ ", Computer won...");
scoreCounter++;
}
**************************************************/

Try splitting your code in methods that each have their own task, that way u can more easily lay out and control the behaviour of your program. E.g. in the case of user input, you can recursively call the method in case of invalid input.
For the while loop, I simply added a counter that increases after every game, until 3.

import java.util.Scanner;
import java.util.Random;
public class RockPaperScissors
{
private static int totalGames = 0;
public static void main(String[] args)
{
Scanner key;
Random randGen;
char userChoice, computerChoice;
int winner;
int computerScore;
int userScore;
/***** INITIALIZATION SECTION *****/
key = new Scanner(System.in);
randGen = new Random();
computerChoice = ' ';
//winner = -1;
computerScore = 0;
userScore = 0;
System.out.println("What is your name?");
String name = key.nextLine();
System.out.println(name + " play rock, paper, or scissors with me!!");
while(totalGames < 3) {
userChoice = getUserChoice(key, false);
/* PROCESSING SECTION */
computerChoice = getComputerChoice(computerChoice, randGen.nextInt(3));
winner = RockPaperScissors.decideWinner(userChoice, computerChoice);
totalGames++;
/* OUTPUT SECTION */
System.out.printf("Player: %c%nComputer: %c%n", userChoice, computerChoice);
switch (winner) {
case 0:
System.out.println("It's a tie!");
System.out.println(name + ": " + userScore + ", Computer:" + computerScore);
break;
case 1:
System.out.println("You won!");
userScore++;
System.out.println(name + ": " + userScore + ", Computer:" + computerScore);
break;
case 2:
System.out.println("Computer won!");
computerScore++;
System.out.println(name + ": " + userScore + ", Computer:" + computerScore);
break;
default:
System.out.println("Invalid choice, try again.");
break;
}
}
//System.out.println("Thanks for playing!);
}
private static char getComputerChoice(char computerChoice, int compInt) {
if (compInt == 0)
{
computerChoice = 'R';
}
else if (compInt == 1)
{
computerChoice = 'P';
}
else if (compInt == 2)
{
computerChoice = 'S';
}
return computerChoice;
}
private static char getUserChoice(Scanner key, boolean retry) {
char userChoice;
/* INPUT SECTION */
if(retry)
System.out.println("You entered an invalid input, please try again...");
System.out.println("Please enter R for rock, P for paper, or S for scissors:");
try {
userChoice = key.next().toUpperCase().charAt(0);
if(userChoice != 'R' && userChoice != 'P' && userChoice != 'S')
return getUserChoice(key, true);
} catch (Exception e){
return getUserChoice(key, true);
}
return userChoice;
}
/***** STATIC METHODS *****/
/**Description: given two characters (R,P, or S) determines winner using rock
* paper rules. Assume input is valid and error checking is done in main
* programme. **/
public static int decideWinner(char p1,char p2)
{
String combo;
combo = String.format("%c%c", p1, p2);
switch(combo)
{
case "RS":
case "PR":
case "SP":
return 1;
case "RP":
case "PS":
case "SR":
return 2;
case "RR":
case "PP":
case "SS":
return 0;
}
return -1;
}
}
/***************************************************
while(userScore == 3)
{
System.out.println("You won the game" +name+ "! Congratulations");
scoreCounter++;
}
while(computerScore == 3)
{
System.out.println("Sorry " +name+ ", Computer won...");
scoreCounter++;
}
**************************************************/