二十、Sentinel规则之熔断降级规则

public class ParamFlowRule extends AbstractRule {
    //限流模式
    private int grade = RuleConstant.FLOW_GRADE_QPS;

    //热点参数的索引
    private Integer paramIdx;

    //The threshold count.
    private double count;

    //流控效果
    private int controlBehavior = RuleConstant.CONTROL_BEHAVIOR_DEFAULT;
    //最大排队等待时长
    private int maxQueueingTimeMs = 0;
    private int burstCount = 0;
    //统计窗口时间长度
    private long durationInSec = 1;

    //参数的额外项，可以针对指定的参数值单独设置限流阈值，不受前面的count影响，仅支持基本数据类型和字符串
    private List<ParamFlowItem> paramFlowItemList = new ArrayList<ParamFlowItem>();

    //额外参数
    private Map<Object, Integer> hotItems = new HashMap<Object, Integer>();

    //是否是集群参数流控规则 默认是false
    private boolean clusterMode = false;
    private ParamFlowClusterConfig clusterConfig;
}

public class ParamFlowItem {
    private String object;//参数值
    private Integer count;//限流阈值
    private String classType;//参数类型
}

public static void initParamFlowRule(){
    List<ParamFlowRule> rules = new ArrayList<>();
    ParamFlowRule rule = new ParamFlowRule();
    //阈值类型：只支持QPS
    rule.setGrade(RuleConstant.FLOW_GRADE_QPS);
    //阈值
    rule.setCount(1);
    //资源名
    rule.setResource("test");
    rule.setParamIdx(0);//指配热点参数的下标
    //统计窗口时间长度
    rule.setDurationInSec(10);

    List<ParamFlowItem> items = new ArrayList<>();
    ParamFlowItem item = new ParamFlowItem();
    item.setClassType(String.class.getTypeName());
    item.setCount(2);
    item.setObject("123456");//需要统计的值

    ParamFlowItem item1 = new ParamFlowItem();
    item1.setClassType(int.class.getName());
    item1.setCount(3);
    item1.setObject("12");

    items.add(item);
    items.add(item1);
    rule.setParamFlowItemList(items);
    rules.add(rule);
    ParamFlowRuleManager.loadRules(rules);
}

@GetMapping("/test")
public String test(
  				@RequestParam("username") String username, 
  				@RequestParam("password") String password, 
  				@RequestParam("age") int age) {
    String echo = echoService.test(username,password,age);
    SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS");
    System.out.println(echo+" | t:"+dateFormat.format(new Date()));
    return "访问成功";
}

public interface EchoService {
    String test(String username, String password, int age);
}

@Service
public class EchoServiceImpl implements EchoService {

    @Override
    @SentinelResource(value = "test",blockHandler = "handleBlockForTest")
    public String test(String username,String password, int age) {
        return "username:"+username +" password:"+password + " age:"+age;
    }

    public String handleBlockForTest(String username, String password,int age, BlockException e){
        return "username:"+username +" password:"+password +" age:"+age+"
          							e:"+e.getClass().getSimpleName();
    }
}