扩展sentinel

一、错误页面优化

实现UrlBlockHandler接口，提供异常处理

package com.uos.contentcenter.sentineltest;

import com.alibaba.csp.sentinel.adapter.servlet.callback.UrlBlockHandler;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.alibaba.csp.sentinel.slots.block.authority.AuthorityException;
import com.alibaba.csp.sentinel.slots.block.degrade.DegradeException;
import com.alibaba.csp.sentinel.slots.block.flow.FlowException;
import com.alibaba.csp.sentinel.slots.block.flow.param.ParamFlowException;
import com.alibaba.csp.sentinel.slots.system.SystemBlockException;
import com.fasterxml.jackson.databind.ObjectMapper;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.springframework.stereotype.Component;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * @author 太子殿下
 * @date 2020/3/29 11:43
 */
@Component
public class MyUrlBlockHandler implements UrlBlockHandler {

    private ErrorMsg msg = null;

    @Override
    public void blocked(HttpServletRequest httpServletRequest, HttpServletResponse response, BlockException ex) throws IOException {
        if (ex instanceof FlowException){
            msg = ErrorMsg.builder()
                    .status(100)
                    .msg("限流了")
                    .build();
        }
        else if (ex instanceof DegradeException){
            msg = ErrorMsg.builder()
                    .status(101)
                    .msg("降级了")
                    .build();
        }
        else if (ex instanceof ParamFlowException){
            msg = ErrorMsg.builder()
                    .status(102)
                    .msg("热点参数限流了")
                    .build();
        }
        else if (ex instanceof SystemBlockException){
            msg = ErrorMsg.builder()
                    .status(103)
                    .msg("系统规则（负载/...不满足要求）")
                    .build();
        }
        else if (ex instanceof AuthorityException){
            msg = ErrorMsg.builder()
                    .status(104)
                    .msg("授权规则不通过")
                    .build();
        }
        // http状态码
        response.setStatus(500);
        response.setCharacterEncoding("utf-8");
        response.setHeader("Content-Type","application/json;charset=utf-8");
        response.setContentType("application/json;charset=utf-8");
        // Spring MVC自带的json操作工具jackson
        new ObjectMapper()
                .writeValue(response.getWriter(),msg);

    }
}
@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
class ErrorMsg{
    private Integer status;
    private String msg;
}

设置限流规则，将出现如下的结果。

二、实现区分来源

实现RequestOriginParser接口

package com.uos.contentcenter.sentineltest;

import com.alibaba.csp.sentinel.adapter.servlet.callback.RequestOriginParser;
import org.apache.commons.lang.StringUtils;
import org.springframework.stereotype.Component;

import javax.servlet.http.HttpServletRequest;

/**
 * @author 太子殿下
 * @date 2020/3/29 13:08
 */
@Component
public class MyRequestOriginParser implements RequestOriginParser {
    @Override
    public String parseOrigin(HttpServletRequest request) {
        // 从请求参数中获取名为origin的参数并返回
        // 如果获取不到origin参数就抛异常
        String origin = request.getParameter("origin");
        if (StringUtils.isBlank(origin)){
            throw new IllegalArgumentException("origin must be specified");
        }
        return origin;
    }
}

新增授权规则

三、RESTful URL支持

实现UrlCleaner接口，重新定义资源名称

package com.uos.contentcenter.sentineltest;

import com.alibaba.csp.sentinel.adapter.servlet.callback.UrlCleaner;
import org.apache.commons.lang.math.NumberUtils;
import org.springframework.stereotype.Component;

import java.util.Arrays;

/**
 * @author 太子殿下
 * @date 2020/3/29 13:40
 */

@Component
public class MyUrlCleaner implements UrlCleaner {
    @Override
    public String clean(String originUrl) {
        // 让/shares/1与/shares/2返回值相同
        // 返回/shares/{number}
        String[] split = originUrl.split("/");
        return Arrays.stream(split)
                .map(string -> {
                    if (NumberUtils.isNumber(string)){
                        return "{number}";
                    }
                    return string;
                })
                .reduce((a,b) -> a + "/" + b)
                .orElse("");
    }
}