spring的bean初始化策略

zlpzlpzyd2023-09-24 12:06

如果当前没有使用 GraalVM 镜像环境，AbstractAutowireCapableBeanFactory 中指定 instantiationStrategy 的值为 CglibSubclassingInstantiationStrategy，即默认创建对象使用的是 cglib。

java 复制代码

/**
	 * Create a new AbstractAutowireCapableBeanFactory.
	 */
	public AbstractAutowireCapableBeanFactory() {
		super();
		ignoreDependencyInterface(BeanNameAware.class);
		ignoreDependencyInterface(BeanFactoryAware.class);
		ignoreDependencyInterface(BeanClassLoaderAware.class);
		if (NativeDetector.inNativeImage()) {
			this.instantiationStrategy = new SimpleInstantiationStrategy();
		}
		else {
			this.instantiationStrategy = new CglibSubclassingInstantiationStrategy();
		}
	}

GraalVM 原生镜像通过启动时设置参数指定 org.graalvm.nativeimage.imagecode，不指定默认为 false。

java 复制代码

public abstract class NativeDetector {

	// See https://github.com/oracle/graal/blob/master/sdk/src/org.graalvm.nativeimage/src/org/graalvm/nativeimage/ImageInfo.java
	private static final boolean imageCode = (System.getProperty("org.graalvm.nativeimage.imagecode") != null);

	/**
	 * Returns {@code true} if invoked in the context of image building or during image runtime, else {@code false}.
	 */
	public static boolean inNativeImage() {
		return imageCode;
	}
}