SpringCloud入门(九)： Zuul 上传&回退&异常处理&跨域
- 2020 年 4 月 6 日
- 筆記
Zuul的上传
1、构建一个上传类
import org.springframework.web.bind.annotation.PostMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.RestController; import org.springframework.web.multipart.MultipartFile; import java.io.*; @RestController @RequestMapping("/file") public class FileUploadController { @PostMapping(value = "/upload", consumes = "multipart/form-data") public Object upload(@RequestParam("file") MultipartFile file) throws IOException { File temp = new File("D:/" + file.getOriginalFilename()); if(!temp.getParentFile().exists()){ temp.getParentFile().mkdir(); } try { file.transferTo(temp); //保存文件 return Boolean.TRUE; } catch (IllegalStateException e) { e.printStackTrace(); return Boolean.FALSE; } catch (IOException e) { e.printStackTrace(); return Boolean.FALSE; } } }
2、配置属性文件
zuul默认文件上传的时候，会走Spring DispatcherServlet，这个时候会对文件大小进行判断，默认为10M；如果要传大文件需要对文件大小进行设置。
zuul.ignored-services=* zuul.routes.use-routing.serviceId=ms-provider-order zuul.routes.use-routing.path=/order-service/** zuul.routes.use-routing.sensitiveHeaders= spring.servlet.multipart.max-file-size=4000MB spring.servlet.multipart.max-request-size=4000MB
通过/zuul来访问，可以绕过DispatcherServlet转为zuulServlet，在上传大文件的时候不需要设置文件大小，但是需要设置hystrix和ribbon的超时时间。
zuul.ignored-services=* zuul.routes.use-routing.serviceId=ms-provider-order zuul.routes.use-routing.path=/order-service/** zuul.routes.use-routing.sensitiveHeaders= hystrix.command.default.execution.isolation.thread.timeoutInMilliseconds=600000 ribbon.ConnectTimeout=100000 ribbon.ReadTimeout=100000
3、通过PostMan测试
zuul的回退
1、自定义一个回退类
import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider; import org.springframework.http.HttpHeaders; import org.springframework.http.HttpStatus; import org.springframework.http.MediaType; import org.springframework.http.client.ClientHttpResponse; import java.io.ByteArrayInputStream; import java.io.IOException; import java.io.InputStream; public class CustomZuulFallBack implements FallbackProvider { @Override public String getRoute() { return "*"; //*表示为所有微服务提供回退 //return "ms-provider-order" //指定某个微服务回退 } @Override public ClientHttpResponse fallbackResponse(String route, Throwable cause) { return new ClientHttpResponse() { @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() { } @Override public InputStream getBody() throws IOException { return new ByteArrayInputStream("后端服务不可用".getBytes()); } @Override public HttpHeaders getHeaders() { HttpHeaders headers = new HttpHeaders(); //和body中的内容编码一致，否则容易乱码 headers.setContentType(MediaType.APPLICATION_JSON_UTF8); return headers; } }; } }
zuul的回退只支持宕机回退（服务挂了）和超时回退（服务请求超时）两种；
如果服务自己抛出的异常（404，500等），zuul的回退监控不到；原因就在于RibbonRoutingFilter的拦截器，在拦截器run中的forward方法，只争对了HystrixRuntimeException的拦截，500等异常会直接由SpringBoot的BasicErrorController接管抛出到页面；
protected ClientHttpResponse forward(RibbonCommandContext context) throws Exception { Map<String, Object> info = this.helper.debug(context.getMethod(), context.getUri(), context.getHeaders(), context.getParams(), context.getRequestEntity()); RibbonCommand command = this.ribbonCommandFactory.create(context); try { ClientHttpResponse response = command.execute(); this.helper.appendDebug(info, response.getRawStatusCode(), response.getHeaders()); return response; } catch (HystrixRuntimeException ex) { return handleException(info, ex); } }
zuul的全局异常处理
1、自定义一个异常处理类
import com.alibaba.fastjson.JSON; import com.netflix.zuul.context.RequestContext; import org.springframework.cloud.netflix.zuul.filters.post.SendErrorFilter; import org.springframework.stereotype.Component; import org.springframework.util.ReflectionUtils; import javax.servlet.http.HttpServletResponse; import java.util.HashMap; import java.util.Map; @Component public class CustomErrorFilter extends SendErrorFilter { @Override public Object run() { try { RequestContext ctx = RequestContext.getCurrentContext(); ExceptionHolder exception = findZuulException(ctx.getThrowable()); //HttpServletRequest request = ctx.getRequest(); HttpServletResponse response = ctx.getResponse(); response.setContentType("text/html; charset=UTF-8"); response.setCharacterEncoding("UTF-8"); Map<String,Object> errorMap = new HashMap<>(); errorMap.put("code","203"); errorMap.put("errMsg",exception.getThrowable().getCause().getMessage()); response.getWriter().write(JSON.toJSONString(errorMap)); } catch (Exception ex) { ReflectionUtils.rethrowRuntimeException(ex); } return null; } }
2、禁用系统自带的异常处理类
zuul.SendErrorFilter.error.disable=true
zuul的跨域问题
import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.web.cors.CorsConfiguration; import org.springframework.web.cors.UrlBasedCorsConfigurationSource; import org.springframework.web.filter.CorsFilter; @Configuration public class CorsConfig { @Bean public CorsFilter corsFilter() { final UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource(); final CorsConfiguration config = new CorsConfiguration(); config.setAllowCredentials(true); // 允许cookies跨域 config.addAllowedOrigin("*");// #允许向该服务器提交请求的URI，*表示全部允许，在SpringMVC中，如果设成*，会自动转成当前请求头中的Origin config.addAllowedHeader("*");// #允许访问的头信息,*表示全部 config.setMaxAge(18000L);// 预检请求的缓存时间（秒），即在这个时间段里，对于相同的跨域请求不会再预检了 config.addAllowedMethod("*");// 允许提交请求的方法，*表示全部允许 source.registerCorsConfiguration("/**", config); return new CorsFilter(source); } }
