org.bremersee.exception.feign.FeignClientExceptionErrorDecoder Maven / Gradle / Ivy
/*
* Copyright 2018 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.bremersee.exception.feign;
import static feign.Util.RETRY_AFTER;
import static java.lang.String.format;
import static java.util.concurrent.TimeUnit.SECONDS;
import feign.Request.HttpMethod;
import feign.Response;
import feign.RetryableException;
import feign.Util;
import feign.codec.ErrorDecoder;
import java.time.OffsetDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Collections;
import java.util.Date;
import lombok.extern.slf4j.Slf4j;
import org.bremersee.exception.RestApiExceptionParser;
import org.bremersee.exception.RestApiExceptionParserImpl;
import org.bremersee.exception.model.RestApiException;
import org.bremersee.http.HttpHeadersHelper;
import org.springframework.http.HttpHeaders;
/**
* This error decoder produces either a {@link FeignClientException} or a {@link
* feign.RetryableException}.
*
* @author Christian Bremer
*/
@Slf4j
public class FeignClientExceptionErrorDecoder implements ErrorDecoder {
private final RestApiExceptionParser parser;
/**
* Instantiates a new feign client exception error decoder.
*/
@SuppressWarnings("WeakerAccess")
public FeignClientExceptionErrorDecoder() {
this.parser = new RestApiExceptionParserImpl();
}
/**
* Instantiates a new Feign client exception error decoder.
*
* @param parser the parser
*/
@SuppressWarnings("unused")
public FeignClientExceptionErrorDecoder(
final RestApiExceptionParser parser) {
this.parser = parser != null ? parser : new RestApiExceptionParserImpl();
}
private static HttpMethod findHttpMethod(final Response response) {
if (response == null) {
return null;
}
if (response.request() == null) {
return null;
}
return response.request().httpMethod();
}
@Override
public Exception decode(final String methodKey, final Response response) {
if (log.isDebugEnabled()) {
log.debug("msg=[Decoding error at {}]", methodKey);
}
final String body = readBody(response);
final String message = format("status %s reading %s", response.status(), methodKey);
final RestApiException restApiException = parser.parseException(
body, response.headers());
if (log.isDebugEnabled() && body != null) {
log.debug("msg=[Is error formatted as rest api exception? {}]",
restApiException != null && !body.equals(restApiException.getMessage()));
}
final FeignClientException feignClientException = new FeignClientException(
response.request(),
response.headers() != null ? Collections.unmodifiableMap(response.headers()) : null,
response.status(),
message,
restApiException);
final HttpHeaders httpHeaders = HttpHeadersHelper.buildHttpHeaders(response.headers());
final Date retryAfter = determineRetryAfter(httpHeaders.getFirst(RETRY_AFTER));
if (retryAfter != null) {
return new RetryableException(
feignClientException.getMessage(),
findHttpMethod(response),
feignClientException,
retryAfter);
}
return feignClientException;
}
private String readBody(final Response response) {
if (response.body() == null) {
return null;
}
try {
return Util.toString(response.body().asReader());
} catch (Exception ignored) {
return null;
}
}
private Date determineRetryAfter(final String retryAfter) {
if (retryAfter == null) {
return null;
}
if (retryAfter.matches("^[0-9]+$")) {
long deltaMillis = SECONDS.toMillis(Long.parseLong(retryAfter));
return new Date(System.currentTimeMillis() + deltaMillis);
}
try {
return Date.from(OffsetDateTime.parse(retryAfter,
DateTimeFormatter.RFC_1123_DATE_TIME).toInstant());
} catch (Exception ignored) {
return null;
}
}
}