test(cache): 集成测试穿透防护(空值缓存,loader 仅调用一次)

src/test/java/com/njcn/middle/cache/integration/CachePenetrationTest.java

@@ -0,0 +1,59 @@
+package com.njcn.middle.cache.integration;
+
+import com.njcn.middle.cache.template.RedisCacheEnhanceTemplate;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.SpringBootConfiguration;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.test.context.SpringBootTest;
+
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Supplier;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+/** 集成测试:回源返回 null 时缓存空值标记,二次查询命中空标记、loader 不再被调用。 */
+@ExtendWith(RedisAvailableCondition.class)
+@SpringBootTest(classes = CachePenetrationTest.TestApp.class,
+        properties = {"redis-cache.key-prefix=it-cache:", "redis-cache.null-ttl-seconds=30"})
+class CachePenetrationTest {
+
+    @Autowired
+    private RedisCacheEnhanceTemplate cache;
+
+    @Test
+    void nullResultCachedAndLoaderCalledOnce() {
+        String key = "pen:missing:1";
+        cache.delete(key);
+
+        AtomicInteger calls = new AtomicInteger();
+        Supplier<User> loader = () -> {
+            calls.incrementAndGet();
+            return null; // 数据不存在
+        };
+
+        assertNull(cache.getOrLoad(key, User.class, 60, loader));
+        assertNull(cache.getOrLoad(key, User.class, 60, loader)); // 命中空值标记
+        assertEquals(1, calls.get());
+
+        cache.delete(key);
+    }
+
+    @SpringBootConfiguration
+    @EnableAutoConfiguration
+    static class TestApp {
+    }
+
+    @Data
+    @AllArgsConstructor
+    @NoArgsConstructor
+    static class User {
+        private Long id;
+        private String name;
+    }
+}