#35 springboot: @Conditional

springboot/autoconfig/src/main/java/hello/config/MemoryConfig.java

@@ -1,11 +1,16 @@
 package hello.config;
 
+import memory.MemoryCondition;
 import memory.MemoryController;
 import memory.MemoryFinder;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Conditional;
 import org.springframework.context.annotation.Configuration;
 
 @Configuration
+//@Conditional(MemoryCondition.class)
+@ConditionalOnProperty(name = "memory", havingValue = "on")
 public class MemoryConfig {
 
     @Bean

springboot/autoconfig/src/main/java/memory/MemoryCondition.java

@@ -0,0 +1,18 @@
+package memory;
+
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.context.annotation.Condition;
+import org.springframework.context.annotation.ConditionContext;
+import org.springframework.core.type.AnnotatedTypeMetadata;
+
+@Slf4j
+public class MemoryCondition implements Condition {
+    @Override
+    public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {
+
+        // -Dmemory=on
+        String memory = context.getEnvironment().getProperty("memory");
+        log.info("memory={}", memory);
+        return "on".equals(memory);
+    }
+}