Spring Boot WebFlux 全局异常处理（404，500）解决IllegalArgumentException: Property 'message

直接上代码，一共需要写3个类：

处理json异常消息的类：

import org.reactivestreams.Publisher;
import org.springframework.core.ResolvableType;
import org.springframework.http.MediaType;
import org.springframework.http.ReactiveHttpOutputMessage;
import org.springframework.http.codec.HttpMessageWriter;
import org.springframework.lang.NonNull;
import org.springframework.stereotype.Component;
import reactor.core.publisher.Mono;

import java.util.Collections;
import java.util.List;
import java.util.Map;

/**
 * @author itning
 * @date 2019/4/29 19:07
 */
@Component
public class JsonHttpMessageWriter implements HttpMessageWriter<Map<String, Object>> {
    @NonNull
    @Override
    public List<MediaType> getWritableMediaTypes() {
        return Collections.singletonList(MediaType.APPLICATION_JSON_UTF8);
    }

    @Override
    public boolean canWrite(@NonNull ResolvableType elementType, MediaType mediaType) {
        return MediaType.APPLICATION_JSON.includes(mediaType);
    }

    @NonNull
    @Override
    public Mono<Void> write(@NonNull Publisher<? extends Map<String, Object>> inputStream,
                            @NonNull ResolvableType elementType,
                            MediaType mediaType,
                            @NonNull ReactiveHttpOutputMessage message,
                            @NonNull Map<String, Object> hints) {
        return Mono.from(inputStream).flatMap(m -> message.writeWith(Mono.just(message.bufferFactory().wrap(transform2Json(m).getBytes()))));
    }

    private String transform2Json(Map<String, Object> sourceMap) {
        return "{" +
                "\"code\":" +
                sourceMap.getOrDefault("code", 500) +
                "," +
                "\"msg\":\"" +
                sourceMap.getOrDefault("msg", "") +
                "\"," +
                "\"data\":\"" +
                sourceMap.getOrDefault("data", "") +
                "\"}";
    }
}

设置错误消息Map集合：

import org.springframework.boot.web.reactive.error.DefaultErrorAttributes;
import org.springframework.stereotype.Component;
import org.springframework.web.reactive.function.server.ServerRequest;
import org.springframework.web.server.ResponseStatusException;

import java.util.LinkedHashMap;
import java.util.Map;

/**
 * @author itning
 * @date 2019/4/29 18:11
 */
@Component
public class GlobalErrorAttributes extends DefaultErrorAttributes {
    @Override
    public Map<String, Object> getErrorAttributes(ServerRequest request, boolean includeStackTrace) {
        Throwable error = getError(request);
        if (error instanceof ResponseStatusException) {
            ResponseStatusException responseStatusException = (ResponseStatusException) error;
            Map<String, Object> errorAttributes = new LinkedHashMap<>();
            errorAttributes.put("code", responseStatusException.getStatus().value());
            errorAttributes.put("msg", responseStatusException.getMessage());
            errorAttributes.put("data", "");
            return errorAttributes;
        } else {
            Map<String, Object> errorAttributes = super.getErrorAttributes(request, includeStackTrace);
            errorAttributes.put("code", errorAttributes.getOrDefault("status", 404));
            errorAttributes.put("msg", error.getMessage());
            errorAttributes.put("data", "");
            return errorAttributes;
        }
    }
}

错误处理：

import org.springframework.boot.autoconfigure.web.ResourceProperties;
import org.springframework.boot.autoconfigure.web.reactive.error.AbstractErrorWebExceptionHandler;
import org.springframework.boot.web.reactive.error.ErrorAttributes;
import org.springframework.context.ApplicationContext;
import org.springframework.core.annotation.Order;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Component;
import org.springframework.web.reactive.function.BodyInserters;
import org.springframework.web.reactive.function.server.*;
import reactor.core.publisher.Mono;

import java.util.Collections;
import java.util.Map;

/**
 * @author itning
 * @date 2019/4/29 18:13
 */
@Component
@Order(-2)
public class GlobalErrorWebExceptionHandler extends AbstractErrorWebExceptionHandler {
    public GlobalErrorWebExceptionHandler(JsonHttpMessageWriter jsonHttpMessageWriter,
                                          ErrorAttributes errorAttributes,
                                          ResourceProperties resourceProperties,
                                          ApplicationContext applicationContext) {
        super(errorAttributes, resourceProperties, applicationContext);
        setMessageWriters(Collections.singletonList(jsonHttpMessageWriter));
    }

    @Override
    protected RouterFunction<ServerResponse> getRoutingFunction(ErrorAttributes errorAttributes) {
        return RouterFunctions.route(
                RequestPredicates.all(), this::renderErrorResponse);
    }

    private Mono<ServerResponse> renderErrorResponse(
            ServerRequest request) {
        Map<String, Object> errorPropertiesMap = getErrorAttributes(request, false);
        return ServerResponse
                .status(Integer.valueOf(errorPropertiesMap.getOrDefault("code", 500).toString()))
                .contentType(MediaType.APPLICATION_JSON_UTF8)
                .body(BodyInserters.fromObject(errorPropertiesMap));
    }
}