4dkankan-parent/4dkankan-gateway/src/main/java/com/fdkankan/gateway/exception/JsonErrorWebExceptionHandler.java

package com.fdkankan.gateway.exception;


import com.fdkankan.common.constant.ServerCode;
import com.fdkankan.common.exception.BusinessException;
import org.springframework.boot.autoconfigure.web.ErrorProperties;
import org.springframework.boot.autoconfigure.web.ResourceProperties;
import org.springframework.boot.autoconfigure.web.reactive.error.DefaultErrorWebExceptionHandler;
import org.springframework.boot.web.error.ErrorAttributeOptions;
import org.springframework.boot.web.reactive.error.ErrorAttributes;
import org.springframework.context.ApplicationContext;
import org.springframework.http.HttpStatus;
import org.springframework.web.reactive.function.server.*;

import java.util.Calendar;
import java.util.HashMap;
import java.util.Map;

public class JsonErrorWebExceptionHandler extends DefaultErrorWebExceptionHandler {

    public JsonErrorWebExceptionHandler(ErrorAttributes errorAttributes,
                                        ResourceProperties resourceProperties,
                                        ErrorProperties errorProperties,
                                        ApplicationContext applicationContext) {
        super(errorAttributes, resourceProperties, errorProperties, applicationContext);
    }

    @Override
    protected Map<String, Object> getErrorAttributes(ServerRequest request, ErrorAttributeOptions options) {

        // 这里其实可以根据异常类型进行定制化逻辑
        Throwable error = super.getError(request);
        Map<String, Object> errorAttributes = new HashMap<>(8);

        if(error instanceof BusinessException){
            errorAttributes.put("code", ((BusinessException) error).getCode());
            errorAttributes.put("message", ((BusinessException) error).getMessage());
        }else{
            errorAttributes.put("code", ServerCode.SYSTEM_ERROR.code());
            errorAttributes.put("message", ServerCode.SYSTEM_ERROR.message());
        }
        errorAttributes.put("method", request.methodName());
        errorAttributes.put("path", request.path());
        errorAttributes.put("timestamp", Calendar.getInstance().getTimeInMillis());
        return errorAttributes;
    }

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

    @Override
    protected int getHttpStatus(Map<String, Object> errorAttributes) {
        // 这里其实可以根据errorAttributes里面的属性定制HTTP响应码
        return HttpStatus.INTERNAL_SERVER_ERROR.value();
    }


}