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本篇內(nèi)容介紹了“springboot事件監(jiān)聽(tīng)器怎么使用”的有關(guān)知識(shí)，在實(shí)際案例的操作過(guò)程中，不少人都會(huì)遇到這樣的困境，接下來(lái)就讓小編帶領(lǐng)大家學(xué)習(xí)一下如何處理這些情況吧！希望大家仔細(xì)閱讀，能夠?qū)W有所成！
下面看一個(gè)簡(jiǎn)單的案例，
@Configuration
public class SelfBusiness {
public static void main(String[] args) {
AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(SelfBusiness.class);
context.getBean(MyService.class).doBusiness();
context.close();
}
@Component
static class MyService {
private static final Logger logger = LoggerFactory.getLogger(MyService.class);
@Autowired
private ApplicationEventPublisher publisher;
public void doBusiness (){
logger.debug("主線業(yè)務(wù)");
logger.debug("發(fā)送短信");
logger.debug("發(fā)送郵件");
}
}運(yùn)行上面的代碼，觀察效果
結(jié)合輸出結(jié)果，這這段代碼要實(shí)現(xiàn)的邏輯是，在主線業(yè)務(wù)執(zhí)行完成后，需要執(zhí)行發(fā)短信，發(fā)郵件等操作，這樣寫也沒(méi)毛病，但不夠優(yōu)雅，從后續(xù)的業(yè)務(wù)可擴(kuò)展性上來(lái)講，不夠友好，如果后續(xù)主線業(yè)務(wù)執(zhí)行完畢，還需再增加一個(gè)其他的審計(jì)操作，則需要新增代碼邏輯，這就將主線業(yè)務(wù)和支線邏輯緊密的耦合了起來(lái)；
就是說(shuō)，我們期待的效果是，主線業(yè)務(wù)根本不關(guān)心其他的業(yè)務(wù)操作，只需要完成自身的邏輯就ok了，這就需要使用到spring提供的事件監(jiān)聽(tīng)器功能；
使用事件監(jiān)聽(tīng)器改造過(guò)程
springboot（spring）的事件監(jiān)聽(tīng)器使用主要有兩種方式，通過(guò)實(shí)現(xiàn)ApplicationListener接口，另一個(gè)就是在類上添加 @EventListener 注解來(lái)實(shí)現(xiàn)，接下來(lái)將對(duì)這兩種方式逐一說(shuō)明；
static class MyEvent extends ApplicationEvent {
public MyEvent(Object source) {
super(source);
}
}可以這么理解，在代碼中，可能有很多種類型的事件，不同的業(yè)務(wù)對(duì)應(yīng)著不同的事件，對(duì)于某個(gè)具體的監(jiān)聽(tīng)器來(lái)說(shuō)，它只想監(jiān)聽(tīng)A這種類型的事件；
@Data
static class Params {
private String id ;
private String name;
private String phone;
}
@Component
static class SmsApplicationListener implements ApplicationListener<MyEvent> {
private static final Logger logger = LoggerFactory.getLogger(SmsApplicationListener.class);
@Override
public void onApplicationEvent(MyEvent myEvent) {
Object source = myEvent.getSource();
try {
Params params = objectMapper.readValue(source.toString(), Params.class);
logger.debug("userId : {}",params.getId());
} catch (JsonProcessingException e) {
e.printStackTrace();
}
logger.debug("執(zhí)行 sms 發(fā)短信業(yè)務(wù)");
}
}
@Component
static class EmailApplicationListener implements ApplicationListener<MyEvent> {
private static final Logger logger = LoggerFactory.getLogger(SmsApplicationListener.class);
@Override
public void onApplicationEvent(MyEvent myEvent) {
Object source = myEvent.getSource();
logger.debug("執(zhí)行 email 發(fā)郵件業(yè)務(wù)");
}
}顯然，這里的監(jiān)聽(tīng)器要監(jiān)聽(tīng)的事件類型，正是上面我們定義的MyEvent ，這樣，當(dāng)業(yè)務(wù)被觸發(fā)的時(shí)候，就可以在onApplicationEvent中拿到傳遞過(guò)來(lái)的參數(shù)，從而執(zhí)行發(fā)短信（發(fā)郵件）業(yè)務(wù)操作了
@Component
static class MyService {
private static final Logger logger = LoggerFactory.getLogger(MyService.class);
@Autowired
private ApplicationEventPublisher publisher;
public void doBusiness (){
Params params = new Params();
params.setId("001");
params.setName("xiaoma");
params.setPhone("133******");
logger.debug("主線業(yè)務(wù)");
try {
publisher.publishEvent(new MyEvent(objectMapper.writeValueAsString(params)));
} catch (JsonProcessingException e) {
e.printStackTrace();
}
//publisher.publishEvent(new MyEvent("MyService doBusiness()"));
//logger.debug("發(fā)送短信");
//logger.debug("發(fā)送郵件");
}
}對(duì)主線業(yè)務(wù)來(lái)說(shuō)，這時(shí)候就不再需要寫發(fā)送短信或郵件邏輯了，只需要一個(gè)publisher將事件發(fā)布出去即可，如果需要傳遞參數(shù)，將參數(shù)一起傳遞過(guò)去
完整的代碼
@Configuration
public class SelfBusiness {
private static ObjectMapper objectMapper = new ObjectMapper();
public static void main(String[] args) {
AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(SelfBusiness.class);
context.getBean(MyService.class).doBusiness();
context.close();
}
@Data
static class Params {
private String id ;
private String name;
private String phone;
}
/**
* 自定義事件對(duì)象
*/
static class MyEvent extends ApplicationEvent {
public MyEvent(Object source) {
super(source);
}
}
@Component
static class MyService {
private static final Logger logger = LoggerFactory.getLogger(MyService.class);
@Autowired
private ApplicationEventPublisher publisher;
public void doBusiness (){
Params params = new Params();
params.setId("001");
params.setName("xiaoma");
params.setPhone("133******");
logger.debug("主線業(yè)務(wù)");
try {
publisher.publishEvent(new MyEvent(objectMapper.writeValueAsString(params)));
} catch (JsonProcessingException e) {
e.printStackTrace();
}
//publisher.publishEvent(new MyEvent("MyService doBusiness()"));
//logger.debug("發(fā)送短信");
//logger.debug("發(fā)送郵件");
}
}
/**
* 監(jiān)聽(tīng)事件觸發(fā)后要執(zhí)行的業(yè)務(wù)
*/
@Component
static class SmsApplicationListener implements ApplicationListener<MyEvent> {
private static final Logger logger = LoggerFactory.getLogger(SmsApplicationListener.class);
@Override
public void onApplicationEvent(MyEvent myEvent) {
Object source = myEvent.getSource();
try {
Params params = objectMapper.readValue(source.toString(), Params.class);
logger.debug("userId : {}",params.getId());
} catch (JsonProcessingException e) {
e.printStackTrace();
}
logger.debug("執(zhí)行 sms 發(fā)短信業(yè)務(wù)");
}
}
@Component
static class EmailApplicationListener implements ApplicationListener<MyEvent> {
private static final Logger logger = LoggerFactory.getLogger(SmsApplicationListener.class);
@Override
public void onApplicationEvent(MyEvent myEvent) {
Object source = myEvent.getSource();
logger.debug("執(zhí)行 email 發(fā)郵件業(yè)務(wù)");
}
}
}再次運(yùn)行上面的代碼，觀察效果，可以看到，仍然能滿足預(yù)期的效果
這種方式不再需要實(shí)現(xiàn)ApplicationListener 接口，而是直接在監(jiān)聽(tīng)類的方法上面添加 @EventListener注解即可，相對(duì)要簡(jiǎn)化了一些，下面直接貼出完整的代碼
package com.congge.config;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import lombok.Data;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.context.ApplicationListener;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.event.EventListener;
import org.springframework.stereotype.Component;
@Configuration
public class SelfBusiness2 {
private static ObjectMapper objectMapper = new ObjectMapper();
public static void main(String[] args) {
AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(SelfBusiness2.class);
context.getBean(MyService.class).doBusiness();
context.close();
}
@Data
static class Params {
private String id ;
private String name;
private String phone;
}
/**
* 自定義事件對(duì)象
*/
static class MyEvent extends ApplicationEvent {
public MyEvent(Object source) {
super(source);
}
}
@Component
static class MyService {
private static final Logger logger = LoggerFactory.getLogger(MyService.class);
@Autowired
private ApplicationEventPublisher publisher;
public void doBusiness (){
Params params = new Params();
params.setId("001");
params.setName("xiaoma");
params.setPhone("133******");
logger.debug("主線業(yè)務(wù)");
try {
publisher.publishEvent(new MyEvent(objectMapper.writeValueAsString(params)));
} catch (JsonProcessingException e) {
e.printStackTrace();
}
}
}
@Component
static class SmsListenerService {
private static final Logger logger = LoggerFactory.getLogger(SmsListenerService.class);
@EventListener
public void smsListener(MyEvent myEvent){
Object source = myEvent.getSource();
try {
SelfBusiness2.Params params = objectMapper.readValue(source.toString(), SelfBusiness2.Params.class);
logger.debug("userId : {}",params.getId());
} catch (JsonProcessingException e) {
e.printStackTrace();
}
logger.debug("執(zhí)行 sms 發(fā)短信業(yè)務(wù)");
}
}
@Component
static class EmailListenerService {
private static final Logger logger = LoggerFactory.getLogger(EmailListenerService.class);
@EventListener
public void emailListener(MyEvent myEvent){
Object source = myEvent.getSource();
try {
SelfBusiness2.Params params = objectMapper.readValue(source.toString(), SelfBusiness2.Params.class);
logger.debug("userId : {}",params.getId());
} catch (JsonProcessingException e) {
e.printStackTrace();
}
logger.debug("執(zhí)行 email 發(fā)郵件業(yè)務(wù)");
}
}
}運(yùn)行上面的代碼，觀察效果，同樣可以達(dá)到預(yù)期的效果
更進(jìn)一步來(lái)說(shuō)，為了提升主線業(yè)務(wù)的邏輯執(zhí)行效率，我們希望發(fā)布事件的業(yè)務(wù)邏輯異步執(zhí)行，這個(gè)該如何做呢?
翻閱源碼可以知道，ApplicationEventPublisher 默認(rèn)發(fā)布事件時(shí)候采用單線程同步發(fā)送，如果需要使用異步，需要自定義 ThreadPoolTaskExecutor ，以及SimpleApplicationEventMulticaster ，因此我們只需要覆蓋一下這兩個(gè)組件的bean即可，在上面的業(yè)務(wù)類中將下面的這兩個(gè)bean添加進(jìn)去；
@Bean
public ThreadPoolTaskExecutor executor() {
ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
executor.setCorePoolSize(5);
executor.setMaxPoolSize(10);
executor.setQueueCapacity(100);
return executor;
}
@Bean
public SimpleApplicationEventMulticaster applicationEventMulticaster(ThreadPoolTaskExecutor executor) {
SimpleApplicationEventMulticaster eventMulticaster = new SimpleApplicationEventMulticaster();
eventMulticaster.setTaskExecutor(executor);
return eventMulticaster;
}這時(shí)候再次運(yùn)行代碼，反復(fù)運(yùn)行多次，就可以看到效果
對(duì)比下上面單線程效果
“springboot事件監(jiān)聽(tīng)器怎么使用”的內(nèi)容就介紹到這里了，感謝大家的閱讀。如果想了解更多行業(yè)相關(guān)的知識(shí)可以關(guān)注億速云網(wǎng)站，小編將為大家輸出更多高質(zhì)量的實(shí)用文章！
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