1.update cobertura settings

2.fix endpoint's degradeRules return value

pom.xml

@@ -200,7 +200,15 @@
                 <groupId>org.codehaus.mojo</groupId>
                 <artifactId>cobertura-maven-plugin</artifactId>
                 <version>${cobertura-maven-plugin.version}</version>
+                <dependencies>
+                    <dependency>
+                        <groupId>org.ow2.asm</groupId>
+                        <artifactId>asm</artifactId>
+                        <version>5.0.3</version>
+                    </dependency>
+                </dependencies>
                 <configuration>
+                    <quiet>true</quiet>
                     <formats>
                         <format>html</format>
                         <format>xml</format>

spring-cloud-alibaba-sentinel/src/main/java/org/springframework/cloud/alibaba/sentinel/endpoint/SentinelEndpoint.java

@@ -19,6 +19,7 @@ package org.springframework.cloud.alibaba.sentinel.endpoint;
 import java.util.HashMap;
 import java.util.Map;
 
+import com.alibaba.csp.sentinel.slots.block.degrade.DegradeRuleManager;
 import org.springframework.boot.actuate.endpoint.annotation.Endpoint;
 import org.springframework.boot.actuate.endpoint.annotation.ReadOperation;
 import org.springframework.cloud.alibaba.sentinel.SentinelProperties;
@@ -67,7 +68,7 @@ public class SentinelEndpoint {
 			final Map<String, Object> rules = new HashMap<>();
 			result.put("rules", rules);
 			rules.put("flowRules", FlowRuleManager.getRules());
-			rules.put("degradeRules", SystemRuleManager.getRules());
+			rules.put("degradeRules", DegradeRuleManager.getRules());
 			rules.put("systemRules", SystemRuleManager.getRules());
 			rules.put("authorityRule", AuthorityRuleManager.getRules());
 			rules.put("paramFlowRule", ParamFlowRuleManager.getRules());