Spring 如何向应用程序上下文初始化事件添加挂钩?
对于一个普通的Servlet,我想您可以声明一个,但是对于SpringMVC,Spring会使这更容易吗 此外,如果我定义了一个上下文侦听器,然后需要访问在我的Spring 如何向应用程序上下文初始化事件添加挂钩?,spring,model-view-controller,applicationcontext,Spring,Model View Controller,Applicationcontext,对于一个普通的Servlet,我想您可以声明一个,但是对于SpringMVC,Spring会使这更容易吗 此外,如果我定义了一个上下文侦听器,然后需要访问在我的servlet.xml或applicationContext.xml中定义的bean,我将如何访问它们 为此,必须创建并注册一个实现ApplicationListener接口的bean,如下所示: package test.pack.age; import org.springframework.context.ApplicationC
servlet.xml
或applicationContext.xml
中定义的bean,我将如何访问它们
为此,必须创建并注册一个实现ApplicationListener
接口的bean,如下所示:
package test.pack.age;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextRefreshedEvent;
public class ApplicationListenerBean implements ApplicationListener {
@Override
public void onApplicationEvent(ApplicationEvent event) {
if (event instanceof ContextRefreshedEvent) {
ApplicationContext applicationContext = ((ContextRefreshedEvent) event).getApplicationContext();
// now you can do applicationContext.getBean(...)
// ...
}
}
}
public class ApplicationListenerBean implements ApplicationListener<ContextRefreshedEvent> {
@Override
public void onApplicationEvent(ContextRefreshedEvent event) {
ApplicationContext applicationContext = event.getApplicationContext();
// now you can do applicationContext.getBean(...)
// ...
}
}
然后在servlet.xml
或applicationContext.xml
文件中注册此bean:
<bean id="eventListenerBean" class="test.pack.age.ApplicationListenerBean" />
从Spring4.2开始,您可以使用
@EventListener
()
我在输入URL时有一个单页应用程序,它正在创建一个HashMap(由我的网页使用),其中包含来自多个数据库的数据。 在服务器启动期间,我执行了以下操作来加载所有内容- 1-已创建ContextListenerClass
public class MyAppContextListener implements ServletContextListener
@Autowired
private MyDataProviderBean myDataProviderBean;
public MyDataProviderBean getMyDataProviderBean() {
return MyDataProviderBean;
}
public void setMyDataProviderBean(MyDataProviderBean MyDataProviderBean) {
this.myDataProviderBean = MyDataProviderBean;
}
@Override
public void contextDestroyed(ServletContextEvent arg0) {
System.out.println("ServletContextListener destroyed");
}
@Override
public void contextInitialized(ServletContextEvent context) {
System.out.println("ServletContextListener started");
ServletContext sc = context.getServletContext();
WebApplicationContext springContext = WebApplicationContextUtils.getWebApplicationContext(sc);
MyDataProviderBean MyDataProviderBean = (MyDataProviderBean)springContext.getBean("myDataProviderBean");
Map<String, Object> myDataMap = MyDataProviderBean.getDataMap();
sc.setAttribute("myMap", myDataMap);
}
公共类MyAppContextListener实现ServletContextListener
@自动连线
私有MyDataProviderBean MyDataProviderBean;
公共MyDataProviderBean getMyDataProviderBean(){
返回MyDataProviderBean;
}
public void setMyDataProviderBean(MyDataProviderBean MyDataProviderBean){
this.myDataProviderBean=myDataProviderBean;
}
@凌驾
公共无效上下文已销毁(ServletContextEvent arg0){
System.out.println(“ServletContextListener已销毁”);
}
@凌驾
公共void contextInitialized(ServletContextEvent上下文){
System.out.println(“ServletContextListener已启动”);
ServletContext sc=context.getServletContext();
WebApplicationContext springContext=WebApplicationContextils.getWebApplicationContext(sc);
MyDataProviderBean MyDataProviderBean=(MyDataProviderBean)springContext.getBean(“MyDataProviderBean”);
Map myDataMap=MyDataProviderBean.getDataMap();
sc.setAttribute(“myMap”,myDataMap);
}
2-在web.xml中添加以下条目
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<listener>
<listener-class>com.context.listener.MyAppContextListener</listener-class>
</listener>
org.springframework.web.context.ContextLoaderListener
com.context.listener.MyAppContextListener
3-在我的控制器类中,更新了代码以首先检查servletContext中的映射
@RequestMapping(value = "/index", method = RequestMethod.GET)
public String index(@ModelAttribute("model") ModelMap model) {
Map<String, Object> myDataMap = new HashMap<String, Object>();
if (context != null && context.getAttribute("myMap")!=null)
{
myDataMap=(Map<String, Object>)context.getAttribute("myMap");
}
else
{
myDataMap = myDataProviderBean.getDataMap();
}
for (String key : myDataMap.keySet())
{
model.addAttribute(key, myDataMap.get(key));
}
return "myWebPage";
}
@RequestMapping(value=“/index”,method=RequestMethod.GET)
公共字符串索引(@modeldattribute(“model”)ModelMap model){
Map myDataMap=newhashmap();
if(context!=null&&context.getAttribute(“myMap”)!=null)
{
myDataMap=(Map)context.getAttribute(“myMap”);
}
其他的
{
myDataMap=myDataProviderBean.getDataMap();
}
for(字符串键:myDataMap.keySet())
{
addAttribute(key,myDataMap.get(key));
}
返回“我的网页”;
}
当我启动tomcat时,它会在startTime期间加载数据映射,并将所有内容放入servletContext中,然后控制器类使用它从已填充的servletContext中获取结果。创建注释
@Retention(RetentionPolicy.RUNTIME)
public @interface AfterSpringLoadComplete {
}
创建类
public class PostProxyInvokerContextListener implements ApplicationListener<ContextRefreshedEvent> {
@Autowired
ConfigurableListableBeanFactory factory;
@Override
public void onApplicationEvent(ContextRefreshedEvent event) {
ApplicationContext context = event.getApplicationContext();
String[] names = context.getBeanDefinitionNames();
for (String name : names) {
try {
BeanDefinition definition = factory.getBeanDefinition(name);
String originalClassName = definition.getBeanClassName();
Class<?> originalClass = Class.forName(originalClassName);
Method[] methods = originalClass.getMethods();
for (Method method : methods) {
if (method.isAnnotationPresent(AfterSpringLoadComplete.class)){
Object bean = context.getBean(name);
Method currentMethod = bean.getClass().getMethod(method.getName(), method.getParameterTypes());
currentMethod.invoke(bean);
}
}
} catch (Exception ignored) {
}
}
}
}
请按照以下步骤在加载应用程序上下文(即应用程序已准备就绪)后进行一些处理
@Component
public class PostApplicationReadyListener implements ApplicationListener<ApplicationReadyEvent> {
public static final Logger LOGGER = LoggerFactory.getLogger(PostApplicationReadyListener.class);
public static final String MODULE = PostApplicationReadyListener.class.getSimpleName();
@Override
public void onApplicationEvent(ApplicationReadyEvent event) {
try {
ApplicationContext context = event.getApplicationContext();
String[] beans = context.getBeanNamesForAnnotation(AfterAppStarted.class);
LOGGER.info("bean found with AfterAppStarted annotation are : {}", Arrays.toString(beans));
for (String beanName : beans) {
Object bean = context.getBean(beanName);
Class<?> targetClass = AopUtils.getTargetClass(bean);
Method[] methods = targetClass.getMethods();
for (Method method : methods) {
if (method.isAnnotationPresent(AfterAppStartedComplete.class)) {
LOGGER.info("Method:[{} of Bean:{}] found with AfterAppStartedComplete Annotation.", method.getName(), beanName);
Method currentMethod = bean.getClass().getMethod(method.getName(), method.getParameterTypes());
LOGGER.info("Going to invoke method:{} of bean:{}", method.getName(), beanName);
currentMethod.invoke(bean);
LOGGER.info("Invocation compeleted method:{} of bean:{}", method.getName(), beanName);
}
}
}
} catch (Exception e) {
LOGGER.warn("Exception occured : ", e);
}
}
}
@组件
公共类PostApplicationReadyListener实现ApplicationListener{
公共静态最终记录器Logger=LoggerFactory.getLogger(PostApplicationReadyListener.class);
公共静态最终字符串模块=PostApplicationReadyListener.class.getSimpleName();
@凌驾
ApplicationEvent上的公共无效(ApplicationReadyEvent事件){
试一试{
ApplicationContext context=event.getApplicationContext();
String[]beans=context.getBeanNamesForAnnotation(AfterAppStarted.class);
info(“使用AfterAppStarted注释找到的bean是:{}”,Arrays.toString(bean));
for(字符串bean名称:bean){
objectbean=context.getBean(beanName);
Class targetClass=AopUtils.getTargetClass(bean);
方法[]methods=targetClass.getMethods();
用于(方法:方法){
if(方法.isAnnotationPresent(AfterAppStartedComplete.class)){
info(“使用AfterAppStartedComplete注释找到的Bean:{}的方法:[{}”,Method.getName(),beanName);
方法currentMethod=bean.getClass().getMethod(方法.getName(),方法.getParameterTypes());
info(“将调用bean:{},method.getName(),beanName的方法:{}”);
调用(bean);
info(“bean的调用完成方法:{}”,method.getName(),beanName);
}
}
}
}捕获(例外e){
LOGGER.warn(“发生异常:”,e);
}
}
}
最后,当您在日志声明应用程序启动之前启动Spring应用程序时,将调用您的侦听器。好的,谢谢。很高兴知道spring3过滤了这些事件。我以前确实注意到applicationlistener类。但是它的钩子也会为RequestHandledEvent调用。你知道如果你使用注释的东西并声明两个类会发生什么吗?非注释(XML)和两个?他们会按照宣布的顺序开火吗?谢谢;)仅供参考,context start的事件是ContextStartedEvent Docs:-@Kumar Sambhav:这是正确的,但也必须提到它们之间的差异。请参见此处:和此处:from:“从Spring3.0开始,ApplicationListener可以通用地声明
<bean class="ua.adeptius.PostProxyInvokerContextListener"/>
@AfterSpringLoadComplete
public void init() {}
@Component
public class PostApplicationReadyListener implements ApplicationListener<ApplicationReadyEvent> {
public static final Logger LOGGER = LoggerFactory.getLogger(PostApplicationReadyListener.class);
public static final String MODULE = PostApplicationReadyListener.class.getSimpleName();
@Override
public void onApplicationEvent(ApplicationReadyEvent event) {
try {
ApplicationContext context = event.getApplicationContext();
String[] beans = context.getBeanNamesForAnnotation(AfterAppStarted.class);
LOGGER.info("bean found with AfterAppStarted annotation are : {}", Arrays.toString(beans));
for (String beanName : beans) {
Object bean = context.getBean(beanName);
Class<?> targetClass = AopUtils.getTargetClass(bean);
Method[] methods = targetClass.getMethods();
for (Method method : methods) {
if (method.isAnnotationPresent(AfterAppStartedComplete.class)) {
LOGGER.info("Method:[{} of Bean:{}] found with AfterAppStartedComplete Annotation.", method.getName(), beanName);
Method currentMethod = bean.getClass().getMethod(method.getName(), method.getParameterTypes());
LOGGER.info("Going to invoke method:{} of bean:{}", method.getName(), beanName);
currentMethod.invoke(bean);
LOGGER.info("Invocation compeleted method:{} of bean:{}", method.getName(), beanName);
}
}
}
} catch (Exception e) {
LOGGER.warn("Exception occured : ", e);
}
}
}