fix(cache): 缺 StringRedisTemplate Bean 时自动装配优雅退场

原仅 @ConditionalOnClass(类在 classpath 恒真),StringRedisTemplate Bean 缺失
(多 ConnectionFactory 致 @ConditionalOnSingleCandidate 不满足,或 exclude
RedisAutoConfiguration)时会因构造参数缺依赖而启动失败。加
@ConditionalOnBean(StringRedisTemplate),配合既有
@AutoConfigureAfter(RedisAutoConfiguration) 在 Redis 装配后求值,缺 Bean 时整类
back off 而非报错。仅改 cache,不动 stream(接受两者风格暂不一致)。

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

src/main/java/com/njcn/middle/cache/autoconfig/RedisCacheAutoConfiguration.java

@@ -4,6 +4,7 @@ import com.njcn.middle.cache.support.CacheKeyBuilder;
 import com.njcn.middle.cache.support.CacheValueCodec;
 import com.njcn.middle.cache.template.RedisCacheEnhanceTemplate;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.data.redis.RedisAutoConfiguration;
@@ -18,6 +19,7 @@ import org.springframework.data.redis.core.StringRedisTemplate;
  */
 @Configuration
 @ConditionalOnClass(StringRedisTemplate.class)
+@ConditionalOnBean(StringRedisTemplate.class)
 @AutoConfigureAfter(RedisAutoConfiguration.class)
 @EnableConfigurationProperties(RedisCacheProperties.class)
 public class RedisCacheAutoConfiguration {

src/test/java/com/njcn/middle/cache/autoconfig/RedisCacheAutoConfigurationTest.java

@@ -40,6 +40,17 @@ class RedisCacheAutoConfigurationTest {
         });
     }
 
+    @Test
+    void backsOffWhenNoStringRedisTemplateBean() {
+        // 不装配 RedisAutoConfiguration,上下文内无 StringRedisTemplate Bean:
+        // 应整类 back off 优雅退场,而非因缺依赖启动失败。
+        new ApplicationContextRunner()
+                .withConfiguration(AutoConfigurations.of(RedisCacheAutoConfiguration.class))
+                .run(ctx -> assertThat(ctx)
+                        .hasNotFailed()
+                        .doesNotHaveBean(RedisCacheEnhanceTemplate.class));
+    }
+
     @Configuration
     static class CustomConfig {
         @Bean