RestTemplate Logging Json Body Config

RestTemplateConfig.kt

import java.io.BufferedReader
import java.io.InputStreamReader
import java.nio.charset.StandardCharsets
import java.util.ArrayList
import java.util.stream.Collectors
import org.slf4j.Logger
import org.slf4j.LoggerFactory
import org.springframework.context.annotation.Bean
import org.springframework.context.annotation.Configuration
import org.springframework.http.HttpRequest
import org.springframework.http.client.BufferingClientHttpRequestFactory
import org.springframework.http.client.ClientHttpRequestExecution
import org.springframework.http.client.ClientHttpRequestFactory
import org.springframework.http.client.ClientHttpRequestInterceptor
import org.springframework.http.client.ClientHttpResponse
import org.springframework.http.client.SimpleClientHttpRequestFactory
import org.springframework.web.client.RestTemplate

@Configuration
class RestTemplateConfig {

    @Bean
    fun restTemplate(): RestTemplate {
        val factory: ClientHttpRequestFactory = BufferingClientHttpRequestFactory(SimpleClientHttpRequestFactory())
        val restTemplate = RestTemplate(factory)
        var interceptors = restTemplate.interceptors
        if (interceptors.isEmpty()) {
            interceptors = ArrayList()
        }
        interceptors.add(LoggingInterceptor())
        restTemplate.interceptors = interceptors

        return restTemplate
    }
}

class LoggingInterceptor : ClientHttpRequestInterceptor {

    var log: Logger = LoggerFactory.getLogger(LoggingInterceptor::class.java)

    override fun intercept(
        req: HttpRequest,
        reqBody: ByteArray,
        ex: ClientHttpRequestExecution
    ): ClientHttpResponse {
        log.debug("Request body: {}", String(reqBody, StandardCharsets.UTF_8))
        val response: ClientHttpResponse = ex.execute(req, reqBody)
        val isr = InputStreamReader(response.body, StandardCharsets.UTF_8)
        val body = BufferedReader(isr).lines().collect(Collectors.joining("\n"))
        log.debug("Response body: {}", body)
        return response
    }
}