实现 RestTemplate 请求全局的日志打印功能

首先实现一个Interceptor器，对请求进行拦截。

/**
 * Web 客户端请求日志打印过滤器
 *
 * @author Jiong
 */
public class TraceLogClientHttpRequestInterceptor implements ClientHttpRequestInterceptor {

    private final static Logger log = LoggerFactory.getLogger(TraceLogClientHttpRequestInterceptor.class);
    private final static long ELAPSED_TIME_OVER_TIME = 1000;
    private final static String LOG_TEMPLATE = "{} {} {} {}";

    @Value("${pms.web.log.printLength:500}")
    private int maxPayloadLength = 500;

    private final JsonConverter jsonConverter;

    public TraceLogClientHttpRequestInterceptor(final JsonConverter jsonConverter) {
        this.jsonConverter = jsonConverter;
    }

    @Override
    public ClientHttpResponse intercept(final HttpRequest request, final byte[] body, final ClientHttpRequestExecution execution) throws IOException {
        final long start = System.currentTimeMillis();
        ClientHttpResponse response = execution.execute(request, body);
        final long cost = System.currentTimeMillis() - start;

        final Map<String, Object> logMap = new HashMap<>(2);

        final MediaType requestMediaType = request.getHeaders().getContentType();

        if (MediaType.APPLICATION_JSON.isCompatibleWith(requestMediaType)
                || MediaType.APPLICATION_FORM_URLENCODED.isCompatibleWith(requestMediaType)) {
            final String requestBody = this.getRequestMessagePayload(body, requestMediaType);
            if (StringUtils.hasText(requestBody)) {
                logMap.put("requestBody", requestBody);
            }
        }

        final MediaType responseMediaType = response.getHeaders().getContentType();

        if (MediaType.APPLICATION_JSON.isCompatibleWith(responseMediaType)) {
            response = new ContentCachingClientHttpResponseWrapper(response);
            final String respBody = this.getResponseMessagePayload(response.getBody(), responseMediaType);
            if (StringUtils.hasText(respBody)) {
                logMap.put("respBody", respBody);
            }
        } else {
            if (Objects.nonNull(responseMediaType)) {
                logMap.put("respType", responseMediaType.getType());
            }
            logMap.put("respLen", response.getHeaders().getContentLength());
        }

        if (response.getStatusCode().value() >= 400) {
            logMap.put("status", response.getStatusCode().value());
            log.warn(LOG_TEMPLATE, cost,
                    request.getMethod().name(),
                    request.getURI(), this.jsonConverter.write(logMap));
        } else {
            if (cost > ELAPSED_TIME_OVER_TIME) {
                log.warn(LOG_TEMPLATE, cost,
                        request.getMethod().name(),
                        request.getURI(), this.jsonConverter.write(logMap));
            } else {
                log.info(LOG_TEMPLATE, cost,
                        request.getMethod().name(),
                        request.getURI(), this.jsonConverter.write(logMap));
            }
        }
        return response;
    }

    protected String getRequestMessagePayload(final byte[] body, final MediaType mediaType) {
        if (body.length > 0) {
            // final int length = Math.min(body.length, this.maxPayloadLength);
            // return new String(body, 0, length, this.getCharset(mediaType));
            // 转换成字符串后再截断可以防止中文乱码.
            return new String(body, this.getCharset(mediaType))
                    .substring(0, Math.min(body.length, this.maxPayloadLength));
        }
        return null;
    }

    protected String getResponseMessagePayload(final InputStream inputStream, final MediaType mediaType) {
        if (!inputStream.markSupported()) {
            log.warn("InputStream mark/reset not supported");
            return null;
        }
        final byte[] buf = new byte[this.maxPayloadLength];
        int length = 0;
        try {
            inputStream.mark(this.maxPayloadLength);
            length = inputStream.read(buf);
            inputStream.reset();
        } catch (final IOException ignore) {
            // 忽略异常
        }
        if (length > 0) {
            return new String(buf, 0, length, this.getCharset(mediaType));
        }
        return null;
    }

    private Charset getCharset(final MediaType mediaType) {
        return Objects.isNull(mediaType.getCharset())
                ? StandardCharsets.UTF_8
                : mediaType.getCharset();
    }


    private static final class ContentCachingClientHttpResponseWrapper implements ClientHttpResponse {

        private final ClientHttpResponse clientHttpResponse;
        private BufferedInputStream inputStream = null;

        private ContentCachingClientHttpResponseWrapper(final ClientHttpResponse clientHttpResponse) {
            this.clientHttpResponse = clientHttpResponse;
        }

        @Override
        public HttpStatusCode getStatusCode() throws IOException {
            return this.clientHttpResponse.getStatusCode();
        }

        @Deprecated(
                since = "6.0"
        )
        @Override
        public int getRawStatusCode() throws IOException {
            return this.clientHttpResponse.getRawStatusCode();
        }

        @Override
        public String getStatusText() throws IOException {
            return this.clientHttpResponse.getStatusText();
        }

        @Override
        public void close() {
            if (Objects.nonNull(this.inputStream)) {
                try {
                    this.inputStream.close();
                } catch (final IOException ignored) {
                    // 忽略关闭异常
                }
            }
            this.clientHttpResponse.close();
        }

        @Override
        public synchronized InputStream getBody() throws IOException {
            if (Objects.isNull(this.inputStream)) {
                this.inputStream = new BufferedInputStream(this.clientHttpResponse.getBody());
            }
            return this.inputStream;
        }

        @Override
        public HttpHeaders getHeaders() {
            return this.clientHttpResponse.getHeaders();
        }
    }

}

然后对 RestTemplateBuilder 的默认值进行配置。

    @Bean
    @Lazy
    @ConditionalOnMissingBean
    public RestTemplateBuilder restTemplateBuilder(final RestTemplateAutoConfiguration restTemplateAutoConfiguration, final RestTemplateBuilderConfigurer restTemplateBuilderConfigurer, final JsonConverter jsonConverter) {
        return restTemplateAutoConfiguration.restTemplateBuilder(restTemplateBuilderConfigurer)
                .setConnectTimeout(Duration.ofSeconds(15))
                .setReadTimeout(Duration.ofSeconds(15))
                .additionalInterceptors(new TraceLogClientHttpRequestInterceptor(jsonConverter));
    }