文章目录

• • @[TOC](文章目录)
• 前言
• 一、使用步骤
• • 1.编写 GlobalExceptionHandler
  • 2.WebFrameworkUtils 工具类
  • 3.json 工具类
  • 4. 网关异常状态码
  • 5. 测试结果如下
• 总结

前言

Gateway网关统一全局异常处理操作 方便前端看到 这里要精细化翻译，默认返回用户是看不懂的 所以需要配置一个 Gateway 的全局异常处理器

---

如果没有网关全局异常的 会如下截图

一、使用步骤

1.编写 GlobalExceptionHandler

代码如下：

package cn.cws.framework.gatewayservice.handler;

import cn.cws.framework.core.common.service.ApiResult;
import cn.cws.framework.gatewayservice.handler.code.GatewayErrorCode;
import cn.cws.framework.gatewayservice.util.WebFrameworkUtils;
import lombok.extern.slf4j.Slf4j;
import org.springframework.boot.web.reactive.error.ErrorWebExceptionHandler;
import org.springframework.core.annotation.Order;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.server.ResponseStatusException;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

/**
 * Gateway 的全局异常处理器，将 Exception 翻译成 ApiResult + 对应的异常编号
 *
 * 在功能上，和 核心 的 GlobalExceptionHandler 类是一致的
 *
 * @author zw
 */
@Component
@Order(-1) // 保证优先级高于默认的 Spring Cloud Gateway 的 ErrorWebExceptionHandler 实现
@Slf4j
public class GlobalExceptionHandler implements ErrorWebExceptionHandler {

    @Override
    public Mono<Void> handle(ServerWebExchange exchange, Throwable ex) {
        // 已经 commit，则直接返回异常
        ServerHttpResponse response = exchange.getResponse();
        if (response.isCommitted()) {
            return Mono.error(ex);
        }

        // 转换成 CommonResult
        ApiResult<?> result;
        if (ex instanceof ResponseStatusException) {
            result = responseStatusExceptionHandler(exchange, (ResponseStatusException) ex);
        } else {
            result = defaultExceptionHandler(exchange, ex);
        }

        // 返回给前端
        return WebFrameworkUtils.writeJSON(exchange, result);
    }

    /**
     * 处理 Spring Cloud Gateway 默认抛出的 ResponseStatusException 异常
     */
    private  ApiResult<?> responseStatusExceptionHandler(ServerWebExchange exchange,
                                                           ResponseStatusException ex) {
        // TODO zw 这里要精细化翻译，默认返回用户是看不懂的
        ServerHttpRequest request = exchange.getRequest();
        log.error("[responseStatusExceptionHandler][uri({}/{}) 发生异常]", request.getURI(), request.getMethod(), ex);
        if (ex.getRawStatusCode()== GatewayErrorCode.SYS_GATEWAY_ERROR_NACOS.getCode()){
            return ApiResult.buildFail(ex.getRawStatusCode(), " 请联系管理人员 : "+ex.getReason()+GatewayErrorCode
                    .SYS_GATEWAY_ERROR_NACOS.getMsg());
        }
        return ApiResult.buildFail(ex.getRawStatusCode(), ex.getReason());
        // return ApiResult.buildFail(ex.getRawStatusCode(), ex.getReason());
    }

    /**
     * 处理系统异常，兜底处理所有的一切
     */
    @ExceptionHandler(value = Exception.class)
    public  ApiResult<?> defaultExceptionHandler(ServerWebExchange exchange,
                                                Throwable ex) {
        ServerHttpRequest request = exchange.getRequest();
        log.error("[defaultExceptionHandler][uri({}/{}) 发生异常]", request.getURI(), request.getMethod(), ex);
        //  TODO zw 是否要插入异常日志呢？
        // 返回 ERROR CommonResult
        log.error("[responseStatusExceptionHandler][uri({}/{}) 发生异常]", request.getURI(), request.getMethod(), ex);
        return ApiResult.buildFail(-1, ex.getMessage());
       // return ApiResult.buildFail(-1,ex.getStackTrace().toString());
    }

}

2.WebFrameworkUtils 工具类

代码如下：

package cn.cws.framework.gatewayservice.util;

import cn.cws.framework.core.common.util.JsonKit;
import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.gateway.route.Route;
import org.springframework.cloud.gateway.support.ServerWebExchangeUtils;
import org.springframework.core.io.buffer.DataBufferFactory;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

/**
 * Web 工具类
 *
 *
 * @author zw
 */
@Slf4j
public class WebFrameworkUtils {

    private static final String HEADER_TENANT_ID = "tenant-id";




    private WebFrameworkUtils() {}

    /**
     * 将 Gateway 请求中的 header，设置到 HttpHeaders 中
     *
     * @param tenantId 租户编号
     * @param httpHeaders WebClient 的请求
     */
    public static void setTenantIdHeader(Long tenantId, HttpHeaders httpHeaders) {
        if (tenantId == null) {
            return;
        }
        httpHeaders.set(HEADER_TENANT_ID, String.valueOf(tenantId));
    }

    public static Long getTenantId(ServerWebExchange exchange) {
        String tenantId = exchange.getRequest().getHeaders().getFirst(HEADER_TENANT_ID);
        return tenantId != null ? Long.parseLong(tenantId) : null;
    }

    /**
     * 返回 JSON 字符串
     *
     * @param exchange 响应
     * @param object 对象，会序列化成 JSON 字符串
     */
    @SuppressWarnings("deprecation") // 必须使用 APPLICATION_JSON_UTF8_VALUE，否则会乱码
    public static Mono<Void> writeJSON(ServerWebExchange exchange, Object object) {
        // 设置 header
        ServerHttpResponse response = exchange.getResponse();
        response.getHeaders().setContentType(MediaType.APPLICATION_JSON_UTF8);
        // 设置 body
        return response.writeWith(Mono.fromSupplier(() -> {
            DataBufferFactory bufferFactory = response.bufferFactory();
            try {

                return bufferFactory.wrap(JsonKit.toJsonByte(object));
            } catch (Exception ex) {
                ServerHttpRequest request = exchange.getRequest();
                log.error("[writeJSON][uri({}/{}) 发生异常]", request.getURI(), request.getMethod(), ex);
                return bufferFactory.wrap(new byte[0]);
            }
        }));
    }

    /**
     * 获得请求匹配的 Route 路由
     *
     * @param exchange 请求
     * @return 路由
     */
    public static Route getGatewayRoute(ServerWebExchange exchange) {
        return exchange.getAttribute(ServerWebExchangeUtils.GATEWAY_ROUTE_ATTR);
    }

}

3.json 工具类

代码如下：

package cn.cws.framework.core.common.util;

import com.fasterxml.jackson.annotation.JsonFilter;
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.ser.FilterProvider;
import com.fasterxml.jackson.databind.ser.impl.SimpleBeanPropertyFilter;
import com.fasterxml.jackson.databind.ser.impl.SimpleFilterProvider;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import lombok.SneakyThrows;

import java.io.IOException;
import java.io.StringWriter;
import java.util.List;
import java.util.Map;

/**
 * @author zw
 */
public class JsonKit {
    public static final ObjectMapper OBJECT_MAPPER = createObjectMapper();
    private static final ObjectMapper IGNORE_OBJECT_MAPPER = createIgnoreObjectMapper();

    private static ObjectMapper createIgnoreObjectMapper() {
        ObjectMapper objectMapper = createObjectMapper();
        objectMapper.addMixIn(Object.class, DynamicMixIn.class);
        return objectMapper;
    }

    /**
     * 初始化ObjectMapper
     */
    public static ObjectMapper createObjectMapper() {
        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.configure(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES, true);
        objectMapper.configure(DeserializationFeature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT, true);
        objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
        objectMapper.configure(DeserializationFeature.USE_BIG_DECIMAL_FOR_FLOATS, true);
        objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
        objectMapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
        objectMapper.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);
        objectMapper.registerModule(new JavaTimeModule());
        return objectMapper;
    }

    public static String object2Json(Object o) {
        StringWriter sw = new StringWriter();
        JsonGenerator gen = null;
        try {
            gen = new JsonFactory().createGenerator(sw);
            OBJECT_MAPPER.writeValue(gen, o);
        } catch (IOException e) {
            throw new RuntimeException("不能序列化对象为Json", e);
        } finally {
            if (null != gen) {
                try {
                    gen.close();
                } catch (IOException e) {
                    throw new RuntimeException("不能序列化对象为Json", e);
                }
            }
        }
        return sw.toString();
    }


    @SneakyThrows
    public static byte[] toJsonByte(Object object) {
        return OBJECT_MAPPER.writeValueAsBytes(object);
    }

    @SneakyThrows
    public static String toJsonString(Object object) {
        return OBJECT_MAPPER.writeValueAsString(object);
    }



    /**
     * @param ignoreFiledNames 要忽略的属性名
     */
    public static String object2Json(Object o, String... ignoreFiledNames) {
        try {
            SimpleBeanPropertyFilter theFilter = SimpleBeanPropertyFilter.serializeAllExcept(ignoreFiledNames);
            FilterProvider filters = new SimpleFilterProvider().addFilter("dynamicFilter", theFilter);
            return IGNORE_OBJECT_MAPPER.writer(filters).writeValueAsString(o);
        } catch (IOException e) {
            throw new RuntimeException("不能序列化对象为Json", e);
        }
    }

    @JsonFilter("dynamicFilter")
    private static class DynamicMixIn {

    }

    public static Map<String, Object> object2Map(Object o) {
        return OBJECT_MAPPER.convertValue(o, Map.class);
    }


    /**
     * 将 json 字段串转换为 对象.
     *
     * @param json  字符串
     * @param clazz 需要转换为的类
     */
    public static <T> T json2Object(String json, Class<T> clazz) {
        try {
            return OBJECT_MAPPER.readValue(json, clazz);
        } catch (IOException e) {
            throw new RuntimeException("将 Json 转换为对象时异常,数据是:" + json, e);
        }
    }

    /**
     * 将 json 字段串转换为 List.
     */
    public static <T> List<T> json2List(String json, Class<T> clazz) {
        JavaType type = OBJECT_MAPPER.getTypeFactory().constructCollectionType(List.class, clazz);
        try {
            return OBJECT_MAPPER.readValue(json, type);
        } catch (Exception e) {
            return null;
        }
    }


    /**
     * 将 json 字段串转换为 数据.
     */
    public static <T> T[] json2Array(String json, Class<T[]> clazz) throws IOException {
        return OBJECT_MAPPER.readValue(json, clazz);

    }

    public static <T> T node2Object(JsonNode jsonNode, Class<T> clazz) {
        try {
            T t = OBJECT_MAPPER.treeToValue(jsonNode, clazz);
            return t;
        } catch (JsonProcessingException e) {
            throw new RuntimeException("将 Json 转换为对象时异常,数据是:" + jsonNode.toString(), e);
        }
    }

    public static JsonNode object2Node(Object o) {
        try {
            if (o == null) {
                return OBJECT_MAPPER.createObjectNode();
            } else {
                return OBJECT_MAPPER.convertValue(o, JsonNode.class);
            }
        } catch (Exception e) {
            throw new RuntimeException("不能序列化对象为Json", e);
        }
    }

    /**
     * JsonNode转换为Java泛型对象，可以是各种类型。
     *
     * @param json String
     * @param tr   TypeReference,例如: new TypeReference< List<FamousUser> >(){}
     * @return List对象列表
     */
    public static <T> T json2GenericObject(String json, TypeReference<T> tr) {

        if (json == null || "".equals(json)) {
            throw new RuntimeException("将 Json 转换为对象时异常,数据是:" + json);
        } else {
            try {
                return (T) OBJECT_MAPPER.readValue(json, tr);
            } catch (Exception e) {
                throw new RuntimeException("将 Json 转换为对象时异常,数据是:" + json, e);
            }
        }
    }
}

4. 网关异常状态码

package cn.cws.framework.gatewayservice.handler.code;

import cn.cws.framework.core.common.constant.ModelEnum;

/**
 * @description: 网关异常状态码
 * @author：zw，微信：yingshengzw
 * @date: 2023/1/16
 * @Copyright： 公众号：搬砖暗夜码农 | 博客：https://itzhouwei.com - 沉淀、分享、成长，让自己和他人都能有所收获！
 */
@SuppressWarnings("all")
public enum GatewayErrorCode {


    SYS_GATEWAY_ERROR_NACOS(503," 服务没有注册到nacos上");



    private String msg;
    private int code;

    GatewayErrorCode(int code, String msg) {
        this.code = code;
        this.msg = msg;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public int getCode() {
        return code;
    }


    public void setCode(int code) {
        this.code = code;
    }

}

5. 测试结果如下

总结

以上就是今天要讲的内容，本文仅仅简单 所以需要配置一个 Gateway 的全局异常处理器