SpringCloud之Zuul网关原理及其配置讲解

<!-- spring cloud Eureka Client 启动器 -->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-eureka</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-zuul</artifactId>
</dependency>
<!-- zuul网关的重试机制，不是使用ribbon内置的重试机制
   是借助spring-retry组件实现的重试
   开启zuul网关重试机制需要增加下述依赖
 -->
<dependency>
   <groupId>org.springframework.retry</groupId>
   <artifactId>spring-retry</artifactId>
</dependency>

@SpringBootApplication
@EnableZuulProxy
public class ZuulApplication {
    public static void main(String[] args) {
        SpringApplication.run(ZuulApplication.class, args);
    }
}

# URL pattern
# 使用路径方式匹配路由规则。
# 参数key结构： zuul.routes.customName.path=xxx
# 用于配置路径匹配规则。
# 其中customName自定义。通常使用要调用的服务名称，方便后期管理
# 可使用的通配符有： * ** ?
# ? 单个字符
# * 任意多个字符，不包含多级路径
# ** 任意多个字符，包含多级路径
zuul.routes.eureka-application-service.path=/apitest
@Component
public class LoggerFilter extends ZuulFilter {
    private static final Logger logger = LoggerFactory.getLogger(LoggerFilter.class);
    
    
    @Override
    public boolean shouldFilter() {
        return true;
    }
    
    @Override
    public Object run() throws ZuulException {
        // 通过zuul，获取请求上下文
        RequestContext rc = RequestContext.getCurrentContext();
        httpservletRequest request = rc.getRequest();
        logger.info("LogFilter1.....method={},url={}",
                request.getMethod(),request.getRequestURL().toString());
        // 可以记录日志、鉴权，给维护人员记录提供定位协助、统计性能
        return null;
    }
    
    @Override
    public String filterType() {
        return "pre";
    }
    
    @Override
    public int filterOrder() {
        return 0;
    }
}

@Component
public class TestFallBbackProvider implements FallbackProvider {
    
    @Override
    public String getRoute() {
        return "eureka-application-service";
    }
    
    @Override
    public ClientHttpResponse fallbackResponse() {
        System.out.println("ClientHttpResponse fallbackResponse()");
        
        List<Map<String, Object>> result = new ArrayList<>();
        Map<String, Object> data = new HashMap<>();
        data.put("message", "服务正忙，请稍后重试");
        result.add(data);
        
        ObjectMapper mapper = new ObjectMapper();
        
        String msg = "";
        try {
            msg = mapper.writeValueAsString(result);
        } catch (JSONProcessingException e) {
            msg = "";
        }
        
        return this.executeFallback(HttpStatus.OK, msg, 
                "application", "json", "utf-8");
    }
    
    @Override
    public ClientHttpResponse fallbackResponse(Throwable cause) {
        System.out.println("ClientHttpResponse fallbackResponse(Throwable cause)");
        if(cause instanceof NullPointerException){
            
            List<Map<String, Object>> result = new ArrayList<>();
            Map<String, Object> data = new HashMap<>();
            data.put("message", "网关超时，请稍后重试");
            result.add(data);
            
            ObjectMapper mapper = new ObjectMapper();
            
            String msg = "";
            try {
                msg = mapper.writeValueAsString(result);
            } catch (JsonProcessingException e) {
                msg = "";
            }
            
            return this.executeFallback(HttpStatus.GATEWAY_TIMEOUT, 
                    msg, "application", "json", "utf-8");
        }else{
            return this.fallbackResponse();
        }
    }
    
    
    private final ClientHttpResponse executeFallback(final HttpStatus status, 
            String contentMsg, String mediaType, String subMediaType, String charsetName) {
        return new ClientHttpResponse() {
            
            @Override
            public HttpHeaders getHeaders() {
                HttpHeaders header = new HttpHeaders();
                MediaType mt = new MediaType(mediaType, subMediaType, Charset.forName(charsetName));
                header.setContentType(mt);
                return header;
            }
            
            @Override
            public InputStream getBody() throws IOException {
                String content = contentMsg;
                return new ByteArrayInputStream(content.getBytes());
            }
            
            @Override
            public String getStatusText() throws IOException {
                return this.getStatusCode().getReasonPhrase();
            }
            
            @Override
            public HttpStatus getStatusCode() throws IOException {
                return status;
            }
            
            @Override
            public int getRawStatusCode() throws IOException {
                return this.getStatusCode().value();
            }
            
            @Override
            public void close() {
            }
        };
    }
}

<dependency>
    <groupId>com.marcosbarbero.cloud</groupId>
    <artifactId>spring-cloud-zuul-ratelimit</artifactId>
    <version>1.3.4.RELEASE</version>
</dependency>

# 开启限流保护
zuul.ratelimit.enabled=true
# 60s内请求超过3次，服务端就抛出异常，60s后可以恢复正常请求
zuul.ratelimit.default-policy.limit=3
zuul.ratelimit.default-policy.refresh-interval=60
# 针对IP进行限流，不影响其他IP
zuul.ratelimit.default-policy.type=origin

# 开启限流保护
zuul.ratelimit.enabled=true
# hystrix-application-client服务60s内请求超过3次，服务抛出异常。
zuul.ratelimit.policies.hystrix-application-client.limit=3
zuul.ratelimit.policies.hystrix-application-client.refresh-interval=60
# 针对IP限流。
zuul.ratelimit.policies.hystrix-application-client.type=origin

# 开启zuul网关重试
zuul.retryable=true
# hystrix超时时间设置
# 线程池隔离，默认超时时间1000ms
hystrix.command.default.execution.isolation.thread.timeoutInMilliseconds=8000
# ribbon超时时间设置：建议设置比Hystrix小
# 请求连接的超时时间: 默认5000ms
ribbon.ConnectTimeout=5000
# 请求处理的超时时间: 默认5000ms
ribbon.ReadTimeout=5000
# 重试次数：MaxAutoRetries表示访问服务集群下原节点（同路径访问）；MaxAutoRetriesNextServer表示访问服务集群下其余节点（换台服务器）
ribbon.MaxAutoRetries=1
ribbon.MaxAutoRetriesNextServer=1
# 开启重试
ribbon.OkToRetryOnAllOperations=true

<dependency>
　　<groupId>org.springframework.retry</groupId>
　　<artifactId>spring-retry</artifactId>
</dependency>