Spring 整理

Spring   接口类 以XXXXXXAware 只要实现它，用装饰者模式实现就可以。

比如：

BeanClassLoaderAware

BeanFactoryAware

ApplicationContextAware 

只要实现set 方法即可

如Spring里面AbstractFactoryBean：

public abstract class AbstractFactoryBean<T>
implements FactoryBean<T>, BeanClassLoaderAware, BeanFactoryAware, InitializingBean, DisposableBean {

       private ClassLoader beanClassLoader = ClassUtils.getDefaultClassLoader();

private BeanFactory beanFactory;

@Override
public void setBeanClassLoader(ClassLoader classLoader) {
this.beanClassLoader = classLoader;
}

@Override
public void setBeanFactory(BeanFactory beanFactory) {
this.beanFactory = beanFactory;
}

}

Spring  ClassUtil 获取默认ClassLoad

public static ClassLoader getDefaultClassLoader() {
ClassLoader cl = null;
try {
cl = Thread.currentThread().getContextClassLoader();
}
catch (Throwable ex) {
// Cannot access thread context ClassLoader - falling back...
}
if (cl == null) {
// No thread context class loader -> use class loader of this class.
cl = ClassUtils.class.getClassLoader();
if (cl == null) {
// getClassLoader() returning null indicates the bootstrap ClassLoader
try {
cl = ClassLoader.getSystemClassLoader();
}
catch (Throwable ex) {
// Cannot access system ClassLoader - oh well, maybe the caller can live with null...
}
}
}
return cl;
}