Fix potential NPE bug when updating ParamFlowRule before the resource…

… has been requested once (#1901)
alibaba · Dec 18, 2020 · 70b457b · 70b457b
1 parent 82826fa
commit 70b457b
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Showing 2 changed files with 18 additions and 1 deletion.
diff --git a/...l/src/main/java/com/alibaba/csp/sentinel/slots/block/flow/param/ParamFlowRuleManager.java b/...l/src/main/java/com/alibaba/csp/sentinel/slots/block/flow/param/ParamFlowRuleManager.java
@@ -138,7 +138,10 @@ private Map<String, List<ParamFlowRule>> aggregateAndPrepareParamRules(List<Para
                 List<ParamFlowRule> oldRuleList = new ArrayList<>(entry.getValue());
                 oldRuleList.removeAll(newRuleList);
                 for (ParamFlowRule rule : oldRuleList) {
-                    ParameterMetricStorage.getParamMetricForResource(resource).clearForRule(rule);
+                    ParameterMetric parameterMetric = ParameterMetricStorage.getParamMetricForResource(resource);
+                    if (parameterMetric != null) {
+                        parameterMetric.clearForRule(rule);
+                    }
                 }
             }
 

diff --git a/...c/test/java/com/alibaba/csp/sentinel/slots/block/flow/param/ParamFlowRuleManagerTest.java b/...c/test/java/com/alibaba/csp/sentinel/slots/block/flow/param/ParamFlowRuleManagerTest.java
@@ -138,4 +138,18 @@ public void testLoadParamRulesAndGet() {
         assertTrue(allRules.contains(ruleC));
         assertTrue(allRules.contains(ruleD));
     }
+
+    @Test
+    public void testLoadParamRulesWithNoMetric() {
+        String resource = "test";
+        ParamFlowRule paramFlowRule = new ParamFlowRule(resource)
+                .setDurationInSec(1).setParamIdx(1);
+        ParamFlowRuleManager.loadRules(Collections.singletonList(paramFlowRule));
+        ParamFlowRule newParamFlowRule = new ParamFlowRule(resource)
+                .setDurationInSec(2).setParamIdx(1);
+        ParamFlowRuleManager.loadRules(Collections.singletonList(newParamFlowRule));
+        List<ParamFlowRule> result = ParamFlowRuleManager.getRulesOfResource(resource);
+        assertEquals(1, result.size());
+        assertEquals(2, result.get(0).getDurationInSec());
+    }
 }