Snippet

Memory Cleanup and Resource Release with @PreDestroy

The @PreDestroy annotation specifies a lifecycle callback that Spring executes right before taking a bean out of service. This allows clearing heavy in-memory data structures and releasing resources to prevent memory leaks during container shutdowns.

snippet.java

java

@Component
public class BufferManager {
 
    private final byte[] memoryBuffer = new byte[1024 * 1024];
 
    @PreDestroy
    public void releaseResources() {
        java.util.Arrays.fill(memoryBuffer, (byte) 0);
        System.out.println("Memory buffer cleared before container shutdown.");
    }
}

spring

Breakdown

private final byte[] memoryBuffer = new byte[1024 * 1024];

Allocates a 1 MB byte array in memory when the Spring component is instantiated.

@PreDestroy

Marks the method to be executed by Spring when the application context is shutting down.

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Memory Cleanup and Resource Release with @PreDestroy

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