Oauth2RestTemplate example - this goes with the spring boot rest oauth example project (https://github.com/royclarkson/spring-rest-service-oauth) but the Greeting class needs to have setters and a default constructor.

Greeting.java

package hello;

public class Greeting {

    private long id;
    private String content;

    public Greeting(){}

    public Greeting(long id, String content) {
        this.id = id;
        this.content = content;
    }

    public long getId() {
        return id;
    }

    public String getContent() {
        return content;
    }

    public void setId(long id) {
        this.id = id;
    }

    public void setContent(String content) {
        this.content = content;
    }
}

RestTemplateTest.java

package hello;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.test.IntegrationTest;
import org.springframework.boot.test.SpringApplicationConfiguration;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.security.oauth2.client.DefaultOAuth2ClientContext;
import org.springframework.security.oauth2.client.OAuth2RestTemplate;
import org.springframework.security.oauth2.client.token.grant.password.ResourceOwnerPasswordResourceDetails;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.test.context.web.WebAppConfiguration;

import static java.lang.String.format;
import static java.util.Arrays.asList;

@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(classes = Application.class)
@WebAppConfiguration
@IntegrationTest("server.port:0")
public class RestTemplateTest {

    @Value("${local.server.port}")
    protected int port;

    @Test
    public void clientAccess() {
        ResourceOwnerPasswordResourceDetails resourceDetails = new ResourceOwnerPasswordResourceDetails();
        resourceDetails.setUsername("roy");
        resourceDetails.setPassword("spring");
        resourceDetails.setAccessTokenUri(format("http://localhost:%d/oauth/token", port));
        resourceDetails.setClientId("clientapp");
        resourceDetails.setClientSecret("123456");
        resourceDetails.setGrantType("password");
        resourceDetails.setScope(asList("read", "write"));

        DefaultOAuth2ClientContext clientContext = new DefaultOAuth2ClientContext();

        OAuth2RestTemplate restTemplate = new OAuth2RestTemplate(resourceDetails, clientContext);
        restTemplate.setMessageConverters(asList(new MappingJackson2HttpMessageConverter()));

        final Greeting greeting = restTemplate.getForObject(format("http://localhost:%d/greeting", port), Greeting.class);

        System.out.println(greeting);
    }
}