OkHttp how to log request body

EDIT

Because I see there is still some people interested by this post, here is the final version (until next improvement) of my log interceptor. I hope it will save some of you guys's time.

Please note that this code is using OkHttp 2.2.0 (and Retrofit 1.9.0)

import com.squareup.okhttp.*;
import okio.Buffer;
import java.io.IOException;

public class LoggingInterceptor implements Interceptor {

private static final String F_BREAK = " %n";
private static final String F_URL = " %s";
private static final String F_TIME = " in %.1fms";
private static final String F_HEADERS = "%s";
private static final String F_RESPONSE = F_BREAK + "Response: %d";
private static final String F_BODY = "body: %s";

private static final String F_BREAKER = F_BREAK + "-------------------------------------------" + F_BREAK;
private static final String F_REQUEST_WITHOUT_BODY = F_URL + F_TIME + F_BREAK + F_HEADERS;
private static final String F_RESPONSE_WITHOUT_BODY = F_RESPONSE + F_BREAK + F_HEADERS + F_BREAKER;
private static final String F_REQUEST_WITH_BODY = F_URL + F_TIME + F_BREAK + F_HEADERS + F_BODY + F_BREAK;
private static final String F_RESPONSE_WITH_BODY = F_RESPONSE + F_BREAK + F_HEADERS + F_BODY + F_BREAK + F_BREAKER;

@Override
public Response intercept(Chain chain) throws IOException {
    Request request = chain.request();

    long t1 = System.nanoTime();
    Response response = chain.proceed(request);
    long t2 = System.nanoTime();

    MediaType contentType = null;
    String bodyString = null;
    if (response.body() != null) {
        contentType = response.body().contentType();
        bodyString = response.body().string();
    }

    double time = (t2 - t1) / 1e6d;

    if (request.method().equals("GET")) {
        System.out.println(String.format("GET " + F_REQUEST_WITHOUT_BODY + F_RESPONSE_WITH_BODY, request.url(), time, request.headers(), response.code(), response.headers(), stringifyResponseBody(bodyString)));
    } else if (request.method().equals("POST")) {
        System.out.println(String.format("POST " + F_REQUEST_WITH_BODY + F_RESPONSE_WITH_BODY, request.url(), time, request.headers(), stringifyRequestBody(request), response.code(), response.headers(), stringifyResponseBody(bodyString)));
    } else if (request.method().equals("PUT")) {
        System.out.println(String.format("PUT " + F_REQUEST_WITH_BODY + F_RESPONSE_WITH_BODY, request.url(), time, request.headers(), request.body().toString(), response.code(), response.headers(), stringifyResponseBody(bodyString)));
    } else if (request.method().equals("DELETE")) {
        System.out.println(String.format("DELETE " + F_REQUEST_WITHOUT_BODY + F_RESPONSE_WITHOUT_BODY, request.url(), time, request.headers(), response.code(), response.headers()));
    }

    if (response.body() != null) {
        ResponseBody body = ResponseBody.create(contentType, bodyString);
        return response.newBuilder().body(body).build();
    } else {
        return response;
    }
}


private static String stringifyRequestBody(Request request) {
    try {
        final Request copy = request.newBuilder().build();
        final Buffer buffer = new Buffer();
        copy.body().writeTo(buffer);
        return buffer.readUtf8();
    } catch (final IOException e) {
        return "did not work";
    }
}

public String stringifyResponseBody(String responseBody) {
    return responseBody;
}
}

I tried to comment on the correct answer from @msung, but my reputation isn't high enough.

Here's modification I did to print RequestBody before making it a full request. It works like a charm. Thanks

private static String bodyToString(final RequestBody request){
        try {
            final RequestBody copy = request;
            final Buffer buffer = new Buffer();
            copy.writeTo(buffer);
            return buffer.readUtf8();
        } 
        catch (final IOException e) {
            return "did not work";
        }
}

Nikola's answer did not work for me. My guess is the implementation of ByteString#toString() changed. This solution worked for me:

private static String bodyToString(final Request request){

    try {
        final Request copy = request.newBuilder().build();
        final Buffer buffer = new Buffer();
        copy.body().writeTo(buffer);
        return buffer.readUtf8();
    } catch (final IOException e) {
        return "did not work";
    }
}

From the documentation of readUtf8():

Removes all bytes from this, decodes them as UTF-8, and returns the string.

which should be what you want.