Spring Cloud Edgware对Hystrix回退的逻辑进行了一些改进。本文将信息探讨新旧版本的回退操作,并分析的原因及改进后的优势。
对于Dalston及更低版本,要想为Zuul提供回退,只需编写代码如下:
@Component
public class MyFallbackProvider implements ZuulFallbackProvider {
@Override
public String getRoute() {
// 表明是为哪个微服务提供回退,*表示为所有微服务提供回退
return "*";
}
@Override
public ClientHttpResponse fallbackResponse() {
return new ClientHttpResponse() {
@Override
public HttpStatus getStatusCode() throws IOException {
// fallback时的状态码
return HttpStatus.OK;
}
@Override
public int getRawStatusCode() throws IOException {
// 数字类型的状态码,本例返回的其实就是200,详见HttpStatus
return this.getStatusCode().value();
}
@Override
public String getStatusText() throws IOException {
// 状态文本,本例返回的其实就是OK,详见HttpStatus
return this.getStatusCode().getReasonPhrase();
}
@Override
public void close() {
}
@Override
public InputStream getBody() throws IOException {
// 响应体
return new ByteArrayInputStream("用户微服务不可用,请稍后再试。".getBytes());
}
@Override
public HttpHeaders getHeaders() {
// headers设定
HttpHeaders headers = new HttpHeaders();
MediaType mt = new MediaType("application", "json", Charset.forName("UTF-8"));
headers.setContentType(mt);
return headers;
}
};
}
}
@Component
public class MyFallbackProvider implements FallbackProvider {
@Override
public String getRoute() {
// 表明是为哪个微服务提供回退,*表示为所有微服务提供回退
return "*";
}
@Override
public ClientHttpResponse fallbackResponse(Throwable cause) {
if (cause instanceof HystrixTimeoutException) {
return response(HttpStatus.GATEWAY_TIMEOUT);
} else {
return this.fallbackResponse();
}
}
@Override
public ClientHttpResponse fallbackResponse() {
return this.response(HttpStatus.INTERNAL_SERVER_ERROR);
}
private ClientHttpResponse response(final HttpStatus status) {
return new ClientHttpResponse() {
@Override
public HttpStatus getStatusCode() throws IOException {
return status;
}
@Override
public int getRawStatusCode() throws IOException {
return status.value();
}
@Override
public String getStatusText() throws IOException {
return status.getReasonPhrase();
}
@Override
public void close() {
}
@Override
public InputStream getBody() throws IOException {
return new ByteArrayInputStream("服务不可用,请稍后再试。".getBytes());
}
@Override
public HttpHeaders getHeaders() {
// headers设定
HttpHeaders headers = new HttpHeaders();
MediaType mt = new MediaType("application", "json", Charset.forName("UTF-8"));
headers.setContentType(mt);
return headers;
}
};
}
}
由代码可知:
ZuulFallbackProvider
接口,从而实现回退;FallbackProvider
接口,从而实现回退。Deprecated
,很可能在未来的版本中被删除。ClientHttpResponsefallbackResponse(Throwablecause);
方法,使用该方法,可获得造成回退的原因。本文分享自 A周立SpringCloud 微信公众号,前往查看
如有侵权,请联系 cloudcommunity@tencent.com 删除。
本文参与 腾讯云自媒体同步曝光计划 ,欢迎热爱写作的你一起参与!