#35 springboot: custom auto config init

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

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+package hello.config;
+
+import memory.MemoryController;
+import memory.MemoryFinder;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class MemoryConfig {
+
+    @Bean
+    public MemoryController memoryController() {
+        return new MemoryController(memoryFinder());
+    }
+
+    @Bean
+    public MemoryFinder memoryFinder() {
+        return new MemoryFinder();
+    }
+}

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

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+package memory;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.ToString;
+
+@Getter
+@AllArgsConstructor
+@ToString
+public class Memory {
+
+    private long used;
+    private long max;
+}

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

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+package memory;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@Slf4j
+@RestController
+@RequiredArgsConstructor
+public class MemoryController {
+
+    private final MemoryFinder memoryFinder;
+
+    @GetMapping("/memory")
+    public Memory system() {
+        Memory memory = memoryFinder.get();
+        log.info("memory={}", memory);
+        return memory;
+    }
+}

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

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+package memory;
+
+import jakarta.annotation.PostConstruct;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class MemoryFinder {
+
+    public Memory get() {
+        long max = Runtime.getRuntime().maxMemory();
+        long total = Runtime.getRuntime().totalMemory();
+        long free = Runtime.getRuntime().freeMemory();
+        long used = total - free;
+        return new Memory(used, max);
+    }
+
+    @PostConstruct
+    public void init() {
+        log.info("init memoryFinder");
+    }
+}