1、目的
实现将一个接口动态代理，并将该代理对象在spring容器初始化完成前注册到spring容器中。实现可以通过@Autowired等注释或其他方法从spring容器中获取该代理对象。
2、灵感来源
翻mybatis的源代码获得，
3、代码
源代码下载
3.1、接口类
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| public interface TestService {
public String sayHello();
}
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3.2、代理类
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| public class MyProxy implements InvocationHandler{
private Class<?> interfaceClass;
public Object bind(Class<?> cls) {
this.interfaceClass = cls;
return Proxy.newProxyInstance(cls.getClassLoader(), new Class[] {interfaceClass}, this);
}
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
return "hello world";
}
}
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3.3、代理工厂
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| public class MyProxyFactory<T> implements FactoryBean<T> {
private Class<T> interfaceClass;
public Class<T> getInterfaceClass() {
return interfaceClass;
}
public void setInterfaceClass(Class<T> interfaceClass) {
this.interfaceClass = interfaceClass;
}
@Override
public T getObject() throws Exception {
return (T) new MyProxy().bind(interfaceClass);
}
@Override
public Class<?> getObjectType() {
return interfaceClass;
}
@Override
public boolean isSingleton() {
return true;
}
}
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3.4、注册spring容器
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| @Component
public class MyRegistryBean implements ApplicationContextAware,BeanDefinitionRegistryPostProcessor{
private ApplicationContext ctx;
@Override
public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
}
@Override
public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry beanDefinitionRegistry) throws BeansException {
Class<?> cls = TestService.class;
BeanDefinitionBuilder builder = BeanDefinitionBuilder.genericBeanDefinition(cls);
GenericBeanDefinition definition = (GenericBeanDefinition) builder.getRawBeanDefinition();
definition.getPropertyValues().add("interfaceClass", definition.getBeanClassName());
definition.setBeanClass(MyProxyFactory.class);
definition.setAutowireMode(GenericBeanDefinition.AUTOWIRE_BY_TYPE);
beanDefinitionRegistry.registerBeanDefinition("testService", definition);
}
@Override
public void setApplicationContext(ApplicationContext ctx) throws BeansException {
this.ctx = ctx;
}
}
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3.5、测试
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| @RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration({"classpath*:applicationContext.xml"})
public class Start {
@Autowired
TestService testService;
@Test
public void test() {
System.out.println(testService.sayHello());
}
}
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控制台成功输出“hello world”，即成功在spring容器初始化完成前，将TestService接口代理，并将代理类注册到spring容器中。