<parent>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-parent</artifactId>
	<version>2.6.3</version>
</parent>
<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-web</artifactId>
</dependency>

java -Dserver.port=9000 -Dcsp.sentinel.dashboard.server=localhost:9000 -Dproject.name=sentinel-dashboard -jar sentinel-dashboard-1.8.3.jar

<dependency>
	<groupId>com.alibaba.cloud</groupId>
	<artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
	<version>2021.0.1.0</version>
</dependency>

@RestController
@RequestMapping(path = "/user")
@RequiredArgsConstructor
@Slf4j
public class UserCtrl {

    private final IUserService userService;

    @GetMapping("/{id}")
    @SneakyThrows
    @SentinelResource(value = "findById", fallback = "findByIdExt")
    public User findById(@PathVariable("id") Long id) {
        TimeUnit.SECONDS.sleep(3);
        return userService.findById(id);
    }

    public User findByIdExt(Long id) {
        log.error("觸發(fā)熔斷");
        throw new IllegalStateException(String.format("id[{}]觸發(fā)熔斷", id));
    }
}

@RestController
@RequestMapping(path = "/user")
@RequiredArgsConstructor
@Slf4j
public class UserCtrl {

    private final IUserService userService;

    @GetMapping("/{id}")
    @SneakyThrows
    public User findById(@PathVariable("id") Long id) {
        TimeUnit.SECONDS.sleep(3);
        return userService.findById(id);
    }

}

import com.alibaba.csp.sentinel.adapter.spring.webmvc.callback.BlockExceptionHandler;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.alibaba.fastjson.JSON;
import com.test.test.model.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.http.HttpStatus;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * @description sentinel 降級處理
 * @date 2024/6/14
 */
@Slf4j
public class WebBlockExceptionHandler implements BlockExceptionHandler {

    @Override
    public void handle(HttpServletRequest httpServletRequest, HttpServletResponse response, BlockException e) throws Exception {
        log.error(String.format("sentinel 降級 資源名稱%s", e.getRule().getResource()), e);

        response.setContentType("application/json");
        response.setStatus(HttpStatus.TOO_MANY_REQUESTS.value());
        response.getWriter().print(JSON.toJSON(R.err(e.getMessage())));
    }
}

import com.alibaba.cloud.sentinel.feign.SentinelFeignAutoConfiguration;
import com.alibaba.csp.sentinel.adapter.spring.webmvc.callback.BlockExceptionHandler;
import com.test.test.hanlder.WebBlockExceptionHandler;
import org.springframework.boot.autoconfigure.AutoConfigureBefore;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * @description
 * @date 2024/6/14
 */
@Configuration(proxyBeanMethods = false)
@AutoConfigureBefore(SentinelFeignAutoConfiguration.class)
public class SentinelAutoConfiguration {

    @Bean
    @ConditionalOnMissingBean
    public BlockExceptionHandler blockExceptionHandler() {
        return new WebBlockExceptionHandler();
    }
}