feat(mq-starter-core): @MqListener 扫描 → MqListenerEndpoint

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

mq-starter-core/src/main/java/com/njcn/mq/container/MqListenerAnnotationBeanPostProcessor.java

@@ -0,0 +1,35 @@
+package com.njcn.mq.container;
+import com.njcn.mq.annotation.MqListener;
+import com.njcn.mq.core.MqContext;
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.config.BeanPostProcessor;
+import org.springframework.core.annotation.AnnotatedElementUtils;
+import java.lang.reflect.Method;
+import java.util.ArrayList;
+import java.util.List;
+
+public class MqListenerAnnotationBeanPostProcessor implements BeanPostProcessor {
+
+    private final List<MqListenerEndpoint> endpoints = new ArrayList<>();
+    public List<MqListenerEndpoint> getEndpoints() { return endpoints; }
+
+    @Override
+    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
+        for (Method m : bean.getClass().getDeclaredMethods()) {
+            MqListener meta = AnnotatedElementUtils.findMergedAnnotation(m, MqListener.class);
+            if (meta == null) continue;
+            Class<?>[] params = m.getParameterTypes();
+            if (params.length < 1 || params.length > 2) {
+                throw new IllegalStateException("@MqListener 方法签名须为 (payload) 或 (payload, MqContext): " + m);
+            }
+            boolean wantsContext = params.length == 2;
+            if (wantsContext && params[1] != MqContext.class) {
+                throw new IllegalStateException("@MqListener 第二参须为 MqContext: " + m);
+            }
+            Class<?> payloadType = params[0];
+            m.setAccessible(true);
+            endpoints.add(new MqListenerEndpoint(bean, m, meta, payloadType, wantsContext));
+        }
+        return bean;
+    }
+}

mq-starter-core/src/main/java/com/njcn/mq/container/MqListenerEndpoint.java

@@ -0,0 +1,15 @@
+package com.njcn.mq.container;
+import com.njcn.mq.annotation.MqListener;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import java.lang.reflect.Method;
+
+@Data
+@AllArgsConstructor
+public class MqListenerEndpoint {
+    private Object bean;
+    private Method method;
+    private MqListener meta;
+    private Class<?> payloadType;
+    private boolean wantsContext;
+}

mq-starter-core/src/test/java/com/njcn/mq/container/MqListenerScanTest.java

@@ -0,0 +1,28 @@
+package com.njcn.mq.container;
+import com.njcn.mq.annotation.MqListener;
+import com.njcn.mq.core.MqContext;
+import org.junit.jupiter.api.Test;
+import java.util.List;
+import static org.junit.jupiter.api.Assertions.*;
+
+class MqListenerScanTest {
+    static class Biz {
+        @MqListener(topic = "LN_Topic", group = "ln_consumer")
+        public void onData(String msg) { }
+        @MqListener(topic = "T2", group = "g2")
+        public void onWithCtx(String msg, MqContext ctx) { }
+    }
+
+    @Test
+    void scan_findsEndpoints_withPayloadTypeAndContextFlag() {
+        MqListenerAnnotationBeanPostProcessor bpp = new MqListenerAnnotationBeanPostProcessor();
+        bpp.postProcessAfterInitialization(new Biz(), "biz");
+        List<MqListenerEndpoint> eps = bpp.getEndpoints();
+        assertEquals(2, eps.size());
+        MqListenerEndpoint e1 = eps.stream().filter(e -> e.getMeta().topic().equals("LN_Topic")).findFirst().orElseThrow(AssertionError::new);
+        assertEquals(String.class, e1.getPayloadType());
+        assertFalse(e1.isWantsContext());
+        MqListenerEndpoint e2 = eps.stream().filter(e -> e.getMeta().topic().equals("T2")).findFirst().orElseThrow(AssertionError::new);
+        assertTrue(e2.isWantsContext());
+    }
+}