springcloud 熔斷處理

在springcloud微服務中，有時候一個服務掛了，我們需要友好的提示，此時我們在api網關路由上做一下過濾，進行友好的提示處理.

代碼如下:

　　

import com.fasterxml.jackson.databind.ObjectMapper;
import com.lujiangchuangzhu.seventeen.api.gateway.vo.BaseVO;
import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Component;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 *Zull路由發起請求失敗時的回滾處理
 * Created by hmb on 2018/3/29.
 */
@Slf4j
@Component
public class GenericFallbackProvider implements FallbackProvider {


    @Override
    public ClientHttpResponse fallbackResponse(Throwable throwable) {
        log.info("服務調用出現了異常:"+throwable.getMessage());
        throwable.printStackTrace();
        return callback();
    }

    /**
     * 如果需要所有調用都支持回退，則return "*"或return null
     * @return
     */
    @Override
    public String getRoute() {
        return "*";
    }

    @Override
    public ClientHttpResponse fallbackResponse() {
        return callback();
    }

    private  ClientHttpResponse callback(){
        return new ClientHttpResponse(){

            @Override
            public InputStream getBody() throws IOException {
                ObjectMapper mapper = new ObjectMapper();
                BaseVO vo=new BaseVO();
                vo.setCode(10000);
                vo.setMessage("服務器開小差了，請稍后再試!");
                String json = mapper.writeValueAsString(vo);
                return new ByteArrayInputStream(json.getBytes("UTF-8"));
            }

            @Override
            public HttpHeaders getHeaders() {
                HttpHeaders headers = new HttpHeaders();
                //和body中的內容編碼一致，否則容易亂碼
                headers.setContentType(MediaType.APPLICATION_JSON_UTF8);
                return headers;
            }

            /**
             * 網關向api服務請求是失敗了，但是消費者客戶端向網關發起的請求是OK的，
             * 不應該把api的404,500等問題拋給客戶端
             * 網關和api服務集群對於客戶端來說是黑盒子
             */
            @Override
            public HttpStatus getStatusCode() throws IOException {
                return HttpStatus.OK;
            }

            @Override
            public int getRawStatusCode() throws IOException {
                return HttpStatus.OK.value();
            }

            @Override
            public String getStatusText() throws IOException {
                return HttpStatus.OK.getReasonPhrase();
            }

            @Override
            public void close() {


            }

        };
    }
}

FallbackProvider 對這個接口實現就可以了.