1.类继承关系
![](https://img.haomeiwen.com/i1297060/40f5c9e4cd74bfbf.png)
2.接口定义
public interface InstantiationStrategy {
//默认构造方法
Object instantiate(RootBeanDefinition beanDefinition, String beanName, BeanFactory owner) throws BeansException;
//指定构造方法
Object instantiate(RootBeanDefinition beanDefinition, String beanName, BeanFactory owner, Constructor<?> ctor,
Object[] args) throws BeansException;
//指定工厂方法
Object instantiate(RootBeanDefinition beanDefinition, String beanName, BeanFactory owner, Object factoryBean,
Method factoryMethod, Object[] args) throws BeansException;
}
3.代码示例
public class InstantiationStrategyTest {
@Test
public void test1() {
DefaultListableBeanFactory factory = new DefaultListableBeanFactory();
RootBeanDefinition beanDefinition=new RootBeanDefinition(TestBean.class);
factory.registerBeanDefinition("testBean", beanDefinition);
InstantiationStrategy strategy= (InstantiationStrategy) FieldUtils.getProtectedFieldValue("instantiationStrategy",factory);
TestBean bean= (TestBean) strategy.instantiate(beanDefinition,"testBean",factory);
}
@Test
public void test2() throws NoSuchMethodException {
DefaultListableBeanFactory factory = new DefaultListableBeanFactory();
RootBeanDefinition beanDefinition=new RootBeanDefinition(TestBean.class);
factory.registerBeanDefinition("testBean", beanDefinition);
Constructor<TestBean> constructor=TestBean.class.getDeclaredConstructor(String.class);
InstantiationStrategy strategy= (InstantiationStrategy) FieldUtils.getProtectedFieldValue("instantiationStrategy",factory);
TestBean bean= (TestBean) strategy.instantiate(beanDefinition,"testBean",factory,constructor,"test1");
}
@Test
public void test3() throws NoSuchMethodException {
DefaultListableBeanFactory factory = new DefaultListableBeanFactory();
RootBeanDefinition beanDefinition=new RootBeanDefinition(TestBean.class);
factory.registerBeanDefinition("testBean", beanDefinition);
TestBeanFactory testBeanFactory=new TestBeanFactory();
InstantiationStrategy strategy= (InstantiationStrategy) FieldUtils.getProtectedFieldValue("instantiationStrategy",factory);
TestBean bean= (TestBean) strategy.instantiate(beanDefinition,"testBean",factory,testBeanFactory,TestBeanFactory.class.getMethod("createBean"));
}
}
参考:
https://my.oschina.net/chengxiaoyuan/blog/823655
http://www.cnblogs.com/sten/p/5762516.html
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