[java] Spring RestTemplate - how to enable full debugging/logging of requests/responses?

Wanted to add my implementation of this as well. I apologize for all the missing semi-colons, this is written in Groovy.

I needed something more configurable than the accepted answer provided. Here's a rest template bean that's very agile and will log everything like the OP is looking for.

Custom Logging Interceptor Class:

import org.springframework.http.HttpRequest
import org.springframework.http.client.ClientHttpRequestExecution
import org.springframework.http.client.ClientHttpRequestInterceptor
import org.springframework.http.client.ClientHttpResponse
import org.springframework.util.StreamUtils

import java.nio.charset.Charset

class HttpLoggingInterceptor implements ClientHttpRequestInterceptor {

    private final static Logger log = LoggerFactory.getLogger(HttpLoggingInterceptor.class)

    @Override
    ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) throws IOException {
        logRequest(request, body)
        ClientHttpResponse response = execution.execute(request, body)
        logResponse(response)
        return response
    }

    private void logRequest(HttpRequest request, byte[] body) throws IOException {
        if (log.isDebugEnabled()) {
            log.debug("===========================request begin================================================")
            log.debug("URI         : {}", request.getURI())
            log.debug("Method      : {}", request.getMethod())
            log.debug("Headers     : {}", request.getHeaders())
            log.debug("Request body: {}", new String(body, "UTF-8"))
            log.debug("==========================request end================================================")
        }
    }

    private void logResponse(ClientHttpResponse response) throws IOException {
        if (log.isDebugEnabled()) {
            log.debug("============================response begin==========================================")
            log.debug("Status code  : {}", response.getStatusCode())
            log.debug("Status text  : {}", response.getStatusText())
            log.debug("Headers      : {}", response.getHeaders())
            log.debug("Response body: {}", StreamUtils.copyToString(response.getBody(), Charset.defaultCharset()))
            log.debug("=======================response end=================================================")
        }
    }
}

Rest Template Bean Definition:

@Bean(name = 'myRestTemplate')
RestTemplate myRestTemplate(RestTemplateBuilder builder) {

    RequestConfig requestConfig = RequestConfig.custom()
            .setConnectTimeout(10 * 1000) // 10 seconds
            .setSocketTimeout(300 * 1000) // 300 seconds
            .build()

    PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager()
    connectionManager.setMaxTotal(10)
    connectionManager.closeIdleConnections(5, TimeUnit.MINUTES)

    CloseableHttpClient httpClient = HttpClients.custom()
            .setConnectionManager(connectionManager)
            .setDefaultRequestConfig(requestConfig)
            .disableRedirectHandling()
            .build()

    RestTemplate restTemplate = builder
            .rootUri("https://domain.server.com")
            .basicAuthorization("username", "password")
            .requestFactory(new BufferingClientHttpRequestFactory(new HttpComponentsClientHttpRequestFactory(httpClient)))
            .interceptors(new HttpLoggingInterceptor())
            .build()

    return restTemplate
}

Implementation:

@Component
class RestService {

    private final RestTemplate restTemplate
    private final static Logger log = LoggerFactory.getLogger(RestService.class)

    @Autowired
    RestService(
            @Qualifier("myRestTemplate") RestTemplate restTemplate
    ) {
        this.restTemplate = restTemplate
    }

    // add specific methods to your service that access the GET and PUT methods

    private <T> T getForObject(String path, Class<T> object, Map<String, ?> params = [:]) {
        try {
            return restTemplate.getForObject(path, object, params)
        } catch (HttpClientErrorException e) {
            log.warn("Client Error (${path}): ${e.responseBodyAsString}")
        } catch (HttpServerErrorException e) {
            String msg = "Server Error (${path}): ${e.responseBodyAsString}"
            log.error(msg, e)
        } catch (RestClientException e) {
            String msg = "Error (${path})"
            log.error(msg, e)
        }
        return null
    }

    private <T> T putForObject(String path, T object) {
        try {
            HttpEntity<T> request = new HttpEntity<>(object)
            HttpEntity<T> response = restTemplate.exchange(path, HttpMethod.PUT, request, T)
            return response.getBody()
        } catch (HttpClientErrorException e) {
            log.warn("Error (${path}): ${e.responseBodyAsString}")
        } catch (HttpServerErrorException e) {
            String msg = "Error (${path}): ${e.responseBodyAsString}"
            log.error(msg, e)
        } catch (RestClientException e) {
            String msg = "Error (${path})"
            log.error(msg, e)
        }
        return null
    }
}