Consumir Servicio Spring Boot + JWT con JAVA

package com.util;

import java.nio.charset.Charset;

import org.apache.tomcat.util.codec.binary.Base64;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.ResponseEntity;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MultiValueMap;
import org.springframework.web.client.RestTemplate;

public class Consumidor {

static final String URL_LOGIN = "http://192.168.20.64:8071/oauth/token";

public static void main(String[] args) {

String usernameHeader = "angularapp";
        String passwordHeader = "12345";
     
String usernameBody = "42596272";
        String passwordBody = "12345";
     
        postLogin(usernameHeader, passwordHeader, usernameBody, passwordBody);

}

private static void postLogin(String usernameHeader, String passwordHeader, String usernameBody, String passwordBody) {

        // Request Header
        HttpHeaders headers = new HttpHeaders();
             
        headers = createHeaders(usernameHeader, passwordHeader);
     
        // Request Body
        MultiValueMap<String, String> body = new LinkedMultiValueMap<String, String>();
        body.add("username", usernameBody);
        body.add("password", passwordBody);
        body.add("grant_type", "password");

        // Request Entity
        HttpEntity<MultiValueMap<String, String>> requestEntity = new HttpEntity<>(body, headers);

        // RestTemplate
        RestTemplate restTemplate = new RestTemplate();

        // POST Login
        ResponseEntity<String> response = restTemplate.exchange(URL_LOGIN, HttpMethod.POST, requestEntity, String.class);

        HttpHeaders responseHeaders = response.getHeaders();
        String responseBody = response.getBody();
        String responseStatus = String.valueOf(response.getStatusCodeValue());

        System.out.println("Status : " + responseStatus);
        System.out.println("Body : " + responseBody);
     
    }

private static HttpHeaders createHeaders(String username, String password){
   return new HttpHeaders() {{
         String auth = username + ":" + password;
         byte[] encodedAuth = Base64.encodeBase64(
            auth.getBytes(Charset.forName("US-ASCII")) );
         String authHeader = "Basic " + new String( encodedAuth );
         set( "Authorization", authHeader );
   }};
}

}