网站ip指向列表,自助手机网站建站软件,专业的企业网站建设公司,网上免费做网站什么是BeanPostProcessor
BeanPostProcessor是Spring框架中的一个重要的扩展点#xff0c;它允许开发者在Bean初始化前后对Bean进行自定义处理。Spring中有很多内置的BeanPostProcessor#xff0c;如AutowiredAnnotationBeanPostProcessor、CommonAnnotationBeanPostProcess…什么是BeanPostProcessor
BeanPostProcessor是Spring框架中的一个重要的扩展点它允许开发者在Bean初始化前后对Bean进行自定义处理。Spring中有很多内置的BeanPostProcessor如AutowiredAnnotationBeanPostProcessor、CommonAnnotationBeanPostProcessor、InitDestroyAnnotationBeanPostProcessor等。
开发者也可以自定义BeanPostProcessor只需要实现BeanPostProcessor接口即可。BeanPostProcessor接口有两个方法
postProcessBeforeInitialization(Object bean, String beanName)在Bean初始化之前执行postProcessAfterInitialization(Object bean, String beanName)在Bean初始化之后执行
自定义BeanPostProcessor
自定义BeanPostProcessor也可以用来做许多有用的事情如
根据Annotation自动为Bean注入依赖在Bean初始化后执行某些操作利用代理机制为Bean添加一些行为
下面是一个简单的自定义BeanPostProcessor例子。 XssFilter是一个安全过滤组件对提交的内容进行过滤作为jar包引入。 但是为了动态的增加不过滤的url选择从配置中读取配置动态修改fliter的urlExclude。
Component
public class XssBeanPostProcessor implements BeanPostProcessor, EnvironmentAware {private Environment environment;private static String FIELD_FILTER filter;private static String FIELD_URLEXCLUSION urlExclude;private static String CONFIG_PROPERTY fliterUrl;private static String beanNameOfFilterBean org.springframework.boot.web.servlet.FilterRegistrationBean;Overridepublic Object postProcessBeforeInitialization(Object o, String s) throws BeansException {return o;}SneakyThrowsOverridepublic Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {if (bean instanceof FilterRegistrationBean) {try {String name bean.getClass().getName();Class beanNameClz Class.forName(name);changeField(beanNameClz, FIELD_FILTER, bean);} catch (Exception e) {e.printStackTrace();}}return bean;}private void changeField(Class clazz, String fieldName, Object obj) throws Exception {Object value getField(clazz, fieldName, obj);// 获取到XssFilter过滤器if (Objects.nonNull(value) value instanceof XssFilter) {XssFilter xssFilter (XssFilter) value;// XssFilter的属性urlExclude为不过滤的urlObject urlExclusionValue getField(xssFilter.getClass(), FIELD_URLEXCLUSION, xssFilter);// 获取配置中不过滤的urlString property environment.getProperty(CONFIG_PROPERTY );if (Objects.nonNull(urlExclusionValue) urlExclusionValue instanceof List !StringUtils.isEmpty(property)) {List list (List) urlExclusionValue;String[] split property.split(,);ListString objects Lists.newArrayList(Arrays.asList(split));objects.addAll(list);Field field ReflectionUtils.findField(xssFilter.getClass(), FIELD_URLEXCLUSION);// 反射修改ReflectionUtils.setField(field, value, objects);}}}private Object getField(Class clazz, String fieldName, Object obj) throws Exception {Field field ReflectionUtils.findField(clazz, fieldName);if (Objects.nonNull(field)) {ReflectionUtils.makeAccessible(field);Object value field.get(obj);return value;}return null;}Overridepublic void setEnvironment(Environment environment) {this.environment environment;}
}
