Sentinel初瞭解 • HelloWorld

import com.alibaba.csp.sentinel.Entry;
import com.alibaba.csp.sentinel.SphU;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.alibaba.csp.sentinel.slots.block.RuleConstant;
import com.alibaba.csp.sentinel.slots.block.flow.FlowRule;
import com.alibaba.csp.sentinel.slots.block.flow.FlowRuleManager;

import java.util.ArrayList;
import java.util.List;

public class Demo1 {

    public static void main(String[] args) {
        // 配置規則.
        initFlowRules();

        for (int i = 0; i < 25; i++){
            // 1.5.0 版本開始可以直接利用 try-with-resources 特性，自動 exit entry
            try (Entry entry = SphU.entry("HelloWorld")) {
                // 被保護的邏輯
                System.out.println("hello world");
            } catch (BlockException ex) {
                // 處理被流控的邏輯
                System.out.println("blocked!");
            }
        }
    }

    private static void initFlowRules(){
        List<FlowRule> rules = new ArrayList<>();
        FlowRule rule = new FlowRule();
        rule.setResource("HelloWorld");
        rule.setGrade(RuleConstant.FLOW_GRADE_QPS);
        // Set limit QPS to 20.
        rule.setCount(20);
        rules.add(rule);
        FlowRuleManager.loadRules(rules);
    }

}

import com.alibaba.csp.sentinel.Entry;
import com.alibaba.csp.sentinel.SphU;
import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.alibaba.csp.sentinel.slots.block.RuleConstant;
import com.alibaba.csp.sentinel.slots.block.flow.FlowRule;
import com.alibaba.csp.sentinel.slots.block.flow.FlowRuleManager;

import java.util.ArrayList;
import java.util.List;

public class Demo2 {

    public static void main(String[] args) {
        // 配置規則.
        initFlowRules();

        for (int i = 0; i < 25; i++){
            // 1.5.0 版本開始可以直接利用 try-with-resources 特性，自動 exit entry
            helloWorld();
        }
    }

    @SentinelResource("HelloWorld")
    public static void helloWorld() {
        // 資源中的邏輯
        System.out.println("hello world");
    }

    private static void initFlowRules(){
        List<FlowRule> rules = new ArrayList<>();
        FlowRule rule = new FlowRule();
        rule.setResource("HelloWorld");
        rule.setGrade(RuleConstant.FLOW_GRADE_QPS);
        // Set limit QPS to 20.
        rule.setCount(20);
        rules.add(rule);
        FlowRuleManager.loadRules(rules);
    }

}