Spring事件发布监听,顺序监听,异步监听方式
最近在做公司的业务需要用到事件通知，比如启动成功打印日志，通知其他业务做相应的操作，就用到了spring的事件通知机制。
1. spring的事件通知
spring的事件通知本质上就是发布-订阅，即生产者-消费者；体现了观察者设计模式或者回调通知，那么spring的事件是如何使用的？
有3要素：发布者-->事件-->监听者
2. spring事件通知使用
spring的事件必须依赖spring容器，所以我在写demo的时候，需要spring-boot-starter。
<dependencies>
<dependency>
<groupid>org.springframework.boot</groupid>
<artifactid>spring-boot-starter</artifactid>
<version>2.1.1.release</version>
</dependency>
<dependency>
<groupid>org.projectlombok</groupid>
<artifactid>lombok</artifactid>
<version>1.18.4</version>
</dependency>
</dependencies>
2.1 spring的事件
spring的事件定义在applicationevent类中，我们可以根据自己的需要自定义事件实体javabean。
@data
public class testspringevent extends applicationevent {
/**
* create a new applicationevent.
*
* @param source the object on which the event initially occurred (never {@code null})
*/
public testspringevent(object source) {
super(source);
}
private integer code;
private string message;
}
跟踪源码：
public abstract class applicationevent extends eventobject {
/** use serialversionuid from spring 1.2 for interoperability. */
private static final long serialversionuid = 7099057708183571937l;
/** system time when the event happened. */
private final long timestamp;
/**
* create a new applicationevent.
* @param source the object on which the event initially occurred (never {@code null})
*/
public applicationevent(object source) {
super(source);
this.timestamp = system.currenttimemillis();
}
/**
* return the system time in milliseconds when the event happened.
*/
public final long gettimestamp() {
return this.timestamp;
}
}
可以看出applicationevent有属性时间戳，即事件的产生的时间，并有object source属性，这个source是有特定意义的，官方的doc是the object on which the event initially occurred.即发布事件的实体类。
进一步跟踪
public class eventobject implements java.io.serializable {
private static final long serialversionuid = 5516075349620653480l;
/**
* the object on which the event initially occurred.
*/
protected transient object source;
/**
* constructs a prototypical event.
*
* @param source the object on which the event initially occurred.
* @exception illegalargumentexception if source is null.
*/
public eventobject(object source) {
if (source == null)
throw new illegalargumentexception("null source");
this.source = source;
}
/**
* the object on which the event initially occurred.
*
* @return the object on which the event initially occurred.
*/
public object getsource() {
return source;
}
/**
* returns a string representation of this eventobject.
*
* @return a a string representation of this eventobject.
*/
public string tostring() {
return getclass().getname() + "[source=" + source + "]";
}
}
定义了一个事件发生的不能序列化的对象
2.2 事件监听
2.2.1 接口方式实现
spring事件的监听由applicationlistener定义，我们写2个，来测试监听它执行的顺序
@component
public class testapplicationlistener implements applicationlistener<testspringevent> {
//@async
public void onapplicationevent(testspringevent event) {
system.out.println("code is:\t" + event.getcode() + ",\tmessage is:\t" + event.getmessage());
}
}
@component
public class testapplicationlistenercopy implements applicationlistener<testspringevent> {
//@async
public void onapplicationevent(testspringevent event) {
system.out.println("2：code is:\t" + event.getcode() + ",\tmessage is:\t" + event.getmessage());
}
}
跟踪代码，可以看出applicationlistener是一个函数式接口
@functionalinterface
public interface applicationlistener<e extends applicationevent> extends eventlistener {
/**
* handle an application event.
* @param event the event to respond to
*/
void onapplicationevent(e event);
}
spring事件监听器的默认是单线程同步执行，异步执行需要加上spring的@async注解，或者自定义线程池实现.
2.2.2 注解实现
也可以使用@eventlistener
package com.feng.spring.listener;
import com.feng.spring.event.testspringevent;
import org.springframework.context.event.eventlistener;
import org.springframework.scheduling.annotation.async;
import org.springframework.stereotype.component;
@component
public class testapplicationlistener2{
//@async
@eventlistener
public void onapplicationevent(testspringevent event) {
system.out.println("step2：code is:\t" + event.getcode() + ",\tmessage is:\t" + event.getmessage());
}
}
@component
public class testapplicationlistener2copy {
//@async
@eventlistener
public void onapplicationevent(testspringevent event) {
system.out.println("step3:code is:\t" + event.getcode() + ",\tmessage is:\t" + event.getmessage());
}
}
同理写2个实现
2.3 事件发布
spring的事件的发布定义在applicationeventpublisher类中，而applicationcontext继承了这个类，因此applicationcontext具有发布事件的能力，而且已经注入spring的bean容器中，可直接获取。
public class springeventmain {
public static void main(string[] args) {
annotationconfigapplicationcontext context = new annotationconfigapplicationcontext();
context.scan(springeventmain.class.getcanonicalname());
context.refresh();
testspringevent testspringevent = new testspringevent(new springeventmain());
testspringevent.setcode(10000);
testspringevent.setmessage("---------my spring task event------------");
context.publishevent(testspringevent);
}
}
注意：
new testspringevent(new springeventmain())
这里的source是传入发布事件的实例对象。
运行后打印如下日志：
/software/jdk1.8.0_191/bin/java -javaagent:/software/ideaide/lib/idea_rt.jar=36631:/software/ideaide/bin -dfile.encoding=utf-8 -classpath /software/jdk1.8.0_191/jre/lib/charsets.jar:/software/jdk1.8.0_191/jre/lib/deploy.jar:/software/jdk1.8.0_191/jre/lib/ext/cldrdata.jar:/software/jdk1.8.0_191/jre/lib/ext/dnsns.jar:/software/jdk1.8.0_191/jre/lib/ext/jaccess.jar:/software/jdk1.8.0_191/jre/lib/ext/jfxrt.jar:/software/jdk1.8.0_191/jre/lib/ext/localedata.jar:/software/jdk1.8.0_191/jre/lib/ext/nashorn.jar:/software/jdk1.8.0_191/jre/lib/ext/sunec.jar:/software/jdk1.8.0_191/jre/lib/ext/sunjce_provider.jar:/software/jdk1.8.0_191/jre/lib/ext/sunpkcs11.jar:/software/jdk1.8.0_191/jre/lib/ext/zipfs.jar:/software/jdk1.8.0_191/jre/lib/javaws.jar:/software/jdk1.8.0_191/jre/lib/jce.jar:/software/jdk1.8.0_191/jre/lib/jfr.jar:/software/jdk1.8.0_191/jre/lib/jfxswt.jar:/software/jdk1.8.0_191/jre/lib/jsse.jar:/software/jdk1.8.0_191/jre/lib/management-agent.jar:/software/jdk1.8.0_191/jre/lib/plugin.jar:/software/jdk1.8.0_191/jre/lib/resources.jar:/software/jdk1.8.0_191/jre/lib/rt.jar:/home/huahua/ideaprojects/feng/spring-event/target/classes:/home/huahua/.m2/repository/org/springframework/boot/spring-boot-starter/2.1.1.release/spring-boot-starter-2.1.1.release.jar:/home/huahua/.m2/repository/org/springframework/boot/spring-boot/2.1.1.release/spring-boot-2.1.1.release.jar:/home/huahua/.m2/repository/org/springframework/spring-context/5.1.3.release/spring-context-5.1.3.release.jar:/home/huahua/.m2/repository/org/springframework/spring-aop/5.1.3.release/spring-aop-5.1.3.release.jar:/home/huahua/.m2/repository/org/springframework/spring-beans/5.1.3.release/spring-beans-5.1.3.release.jar:/home/huahua/.m2/repository/org/springframework/spring-expression/5.1.3.release/spring-expression-5.1.3.release.jar:/home/huahua/.m2/repository/org/springframework/boot/spring-boot-autoconfigure/2.1.1.release/spring-boot-autoconfigure-2.1.1.release.jar:/home/huahua/.m2/repository/org/springframework/boot/spring-boot-starter-logging/2.1.1.release/spring-boot-starter-logging-2.1.1.release.jar:/home/huahua/.m2/repository/ch/qos/logback/logback-classic/1.2.3/logback-classic-1.2.3.jar:/home/huahua/.m2/repository/ch/qos/logback/logback-core/1.2.3/logback-core-1.2.3.jar:/home/huahua/.m2/repository/org/slf4j/slf4j-api/1.7.25/slf4j-api-1.7.25.jar:/home/huahua/.m2/repository/org/apache/logging/log4j/log4j-to-slf4j/2.11.1/log4j-to-slf4j-2.11.1.jar:/home/huahua/.m2/repository/org/apache/logging/log4j/log4j-api/2.11.1/log4j-api-2.11.1.jar:/home/huahua/.m2/repository/org/slf4j/jul-to-slf4j/1.7.25/jul-to-slf4j-1.7.25.jar:/home/huahua/.m2/repository/javax/annotation/javax.annotation-api/1.3.2/javax.annotation-api-1.3.2.jar:/home/huahua/.m2/repository/org/springframework/spring-core/5.1.3.release/spring-core-5.1.3.release.jar:/home/huahua/.m2/repository/org/springframework/spring-jcl/5.1.3.release/spring-jcl-5.1.3.release.jar:/home/huahua/.m2/repository/org/yaml/snakeyaml/1.23/snakeyaml-1.23.jar:/home/huahua/.m2/repository/org/projectlombok/lombok/1.18.4/lombok-1.18.4.jar com.feng.spring.springeventmain
17:54:05.347 [main] debug org.springframework.context.annotation.classpathbeandefinitionscanner - identified candidate component class: file [/home/huahua/ideaprojects/feng/spring-event/target/classes/com/feng/spring/listener/testapplicationlistener.class]
17:54:05.352 [main] debug org.springframework.context.annotation.classpathbeandefinitionscanner - identified candidate component class: file [/home/huahua/ideaprojects/feng/spring-event/target/classes/com/feng/spring/listener/testapplicationlistener2.class]
17:54:05.353 [main] debug org.springframework.context.annotation.classpathbeandefinitionscanner - identified candidate component class: file [/home/huahua/ideaprojects/feng/spring-event/target/classes/com/feng/spring/listener/testapplicationlistener3.class]
17:54:05.353 [main] debug org.springframework.context.annotation.classpathbeandefinitionscanner - identified candidate component class: file [/home/huahua/ideaprojects/feng/spring-event/target/classes/com/feng/spring/listener/testapplicationlistenercopy.class]
17:54:05.358 [main] debug org.springframework.context.annotation.annotationconfigapplicationcontext - refreshing org.springframework.context.annotation.annotationconfigapplicationcontext@64b8f8f4
17:54:05.380 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'org.springframework.context.annotation.internalconfigurationannotationprocessor'
17:54:05.438 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'org.springframework.context.event.internaleventlistenerprocessor'
17:54:05.440 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'org.springframework.context.event.internaleventlistenerfactory'
17:54:05.443 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'org.springframework.context.annotation.internalautowiredannotationprocessor'
17:54:05.444 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'org.springframework.context.annotation.internalcommonannotationprocessor'
17:54:05.451 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'testapplicationlistener'
17:54:05.466 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'testapplicationlistener2'
17:54:05.470 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'testapplicationlistener3'
17:54:05.471 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'testapplicationlistenercopy'
17:54:05.490 [main] debug org.springframework.context.event.eventlistenermethodprocessor - 1 @eventlistener methods processed on bean 'testapplicationlistener2': {public void com.feng.spring.listener.testapplicationlistener2.onapplicationevent(com.feng.spring.event.testspringevent)=@org.springframework.context.event.eventlistener(condition=, value=[], classes=[])}
17:54:05.491 [main] debug org.springframework.context.event.eventlistenermethodprocessor - 1 @eventlistener methods processed on bean 'testapplicationlistener3': {public void com.feng.spring.listener.testapplicationlistener3.onapplicationevent(com.feng.spring.event.testspringevent)=@org.springframework.context.event.eventlistener(condition=, value=[], classes=[])}
step2:code is: 10000, message is: ---------my spring task event------------
step3:code is: 10000, message is: ---------my spring task event------------
code is: 10000, message is: ---------my spring task event------------
2：code is: 10000, message is: ---------my spring task event------------
process finished with exit code 0
说明spring事件发布订阅成功。同时使用注解的监听比实现类监听先监听，如果我们需要监听的执行顺序怎么办？比如某些监听器先执行？
2.4 spring顺序监听器
上面的示例，其实都是注解或者都是实现类，监听器是没有顺序的。如果我们要实现顺序监听呢？我么需要ordered接口的实现，spring提供的实现或者暴露的实现接口如下
如果需要执行顺序，spring提供smartapplicationlistener与genericapplicationlistener可供选择。
其中genericapplicationlistener，spring官方推荐我们提供adapter实现
/**
* extended variant of the standard {@link applicationlistener} interface,
* exposing further metadata such as the supported event and source type.
*
* <p>as of spring framework 4.2, this interface supersedes the class-based
* {@link smartapplicationlistener} with full handling of generic event types.
*
* @author stephane nicoll
* @since 4.2
* @see smartapplicationlistener
* @see genericapplicationlisteneradapter
*/
/**
* extended variant of the standard {@link applicationlistener} interface,
* exposing further metadata such as the supported event and source type.
*
* <p>as of spring framework 4.2, this interface supersedes the class-based
* {@link smartapplicationlistener} with full handling of generic event types.
*
* @author stephane nicoll
* @since 4.2
* @see smartapplicationlistener
* @see genericapplicationlisteneradapter
*/
public interface genericapplicationlistener extends applicationlistener<applicationevent>, ordered {
/**
* determine whether this listener actually supports the given event type.
* @param eventtype the event type (never {@code null})
*/
boolean supportseventtype(resolvabletype eventtype);
/**
* determine whether this listener actually supports the given source type.
* <p>the default implementation always returns {@code true}.
* @param sourcetype the source type, or {@code null} if no source
*/
default boolean supportssourcetype(@nullable class<?> sourcetype) {
return true;
}
/**
* determine this listener's order in a set of listeners for the same event.
* <p>the default implementation returns {@link #lowest_precedence}.
*/
@override
default int getorder() {
return lowest_precedence;
}
}
其实applicationlistener在spring中提供了很多默认实现，其中就有smartapplicationlistener，智能监听器。
下面来试试
*/
public interface smartapplicationlistener extends applicationlistener<applicationevent>, ordered {
/**
* determine whether this listener actually supports the given event type.
* @param eventtype the event type (never {@code null})
*/
//supportseventtype与supportssourcetype同时true，监听器才会执行
//监听器支持的事件类型
boolean supportseventtype(class<? extends applicationevent> eventtype);
/**
* determine whether this listener actually supports the given source type.
* <p>the default implementation always returns {@code true}.
* @param sourcetype the source type, or {@code null} if no source
*/
//supportseventtype与supportssourcetype同时true，监听器才会执行
//监听事件发布的类
default boolean supportssourcetype(@nullable class<?> sourcetype) {
return true;
}
/**
* determine this listener's order in a set of listeners for the same event.
* <p>the default implementation returns {@link #lowest_precedence}.
*/
@override
default int getorder() {
return lowest_precedence;
}
}
3个实现方法。支持的类型，支持的事件类，执行顺序
package com.feng.spring.listener;
import com.feng.spring.springeventmain;
import com.feng.spring.event.testspringevent;
import org.springframework.context.applicationevent;
import org.springframework.context.event.smartapplicationlistener;
import org.springframework.stereotype.component;
@component
public class orderedlistener implements smartapplicationlistener {
public boolean supportseventtype(class<? extends applicationevent> eventtype) {
return eventtype== testspringevent.class;
}
public boolean supportssourcetype(class<?> sourcetype) {
return springeventmain.class==sourcetype;
}
public int getorder() {
return 5;
}
public void onapplicationevent(applicationevent event) {
system.out.println("my execute step is 555555555555555555555555555");
}
}
@component
public class orderedlistenercopy implements smartapplicationlistener {
public boolean supportseventtype(class<? extends applicationevent> eventtype) {
return eventtype== testspringevent.class;
}
public boolean supportssourcetype(class<?> sourcetype) {
return springeventmain.class==sourcetype;
}
public int getorder() {
return 6;
}
public void onapplicationevent(applicationevent event) {
system.out.println("my execute step is 6666666666666666666666666666");
}
}
同理写2个，执行结果如下：
/software/jdk1.8.0_191/bin/java -agentlib:jdwp=transport=dt_socket,address=127.0.0.1:46603,suspend=y,server=n -javaagent:/software/ideaide/lib/rt/debugger-agent.jar -dfile.encoding=utf-8 -classpath /software/jdk1.8.0_191/jre/lib/charsets.jar:/software/jdk1.8.0_191/jre/lib/deploy.jar:/software/jdk1.8.0_191/jre/lib/ext/cldrdata.jar:/software/jdk1.8.0_191/jre/lib/ext/dnsns.jar:/software/jdk1.8.0_191/jre/lib/ext/jaccess.jar:/software/jdk1.8.0_191/jre/lib/ext/jfxrt.jar:/software/jdk1.8.0_191/jre/lib/ext/localedata.jar:/software/jdk1.8.0_191/jre/lib/ext/nashorn.jar:/software/jdk1.8.0_191/jre/lib/ext/sunec.jar:/software/jdk1.8.0_191/jre/lib/ext/sunjce_provider.jar:/software/jdk1.8.0_191/jre/lib/ext/sunpkcs11.jar:/software/jdk1.8.0_191/jre/lib/ext/zipfs.jar:/software/jdk1.8.0_191/jre/lib/javaws.jar:/software/jdk1.8.0_191/jre/lib/jce.jar:/software/jdk1.8.0_191/jre/lib/jfr.jar:/software/jdk1.8.0_191/jre/lib/jfxswt.jar:/software/jdk1.8.0_191/jre/lib/jsse.jar:/software/jdk1.8.0_191/jre/lib/management-agent.jar:/software/jdk1.8.0_191/jre/lib/plugin.jar:/software/jdk1.8.0_191/jre/lib/resources.jar:/software/jdk1.8.0_191/jre/lib/rt.jar:/home/huahua/ideaprojects/feng/spring-event/target/classes:/home/huahua/.m2/repository/org/springframework/boot/spring-boot-starter/2.1.1.release/spring-boot-starter-2.1.1.release.jar:/home/huahua/.m2/repository/org/springframework/boot/spring-boot/2.1.1.release/spring-boot-2.1.1.release.jar:/home/huahua/.m2/repository/org/springframework/spring-context/5.1.3.release/spring-context-5.1.3.release.jar:/home/huahua/.m2/repository/org/springframework/spring-aop/5.1.3.release/spring-aop-5.1.3.release.jar:/home/huahua/.m2/repository/org/springframework/spring-beans/5.1.3.release/spring-beans-5.1.3.release.jar:/home/huahua/.m2/repository/org/springframework/spring-expression/5.1.3.release/spring-expression-5.1.3.release.jar:/home/huahua/.m2/repository/org/springframework/boot/spring-boot-autoconfigure/2.1.1.release/spring-boot-autoconfigure-2.1.1.release.jar:/home/huahua/.m2/repository/org/springframework/boot/spring-boot-starter-logging/2.1.1.release/spring-boot-starter-logging-2.1.1.release.jar:/home/huahua/.m2/repository/ch/qos/logback/logback-classic/1.2.3/logback-classic-1.2.3.jar:/home/huahua/.m2/repository/ch/qos/logback/logback-core/1.2.3/logback-core-1.2.3.jar:/home/huahua/.m2/repository/org/slf4j/slf4j-api/1.7.25/slf4j-api-1.7.25.jar:/home/huahua/.m2/repository/org/apache/logging/log4j/log4j-to-slf4j/2.11.1/log4j-to-slf4j-2.11.1.jar:/home/huahua/.m2/repository/org/apache/logging/log4j/log4j-api/2.11.1/log4j-api-2.11.1.jar:/home/huahua/.m2/repository/org/slf4j/jul-to-slf4j/1.7.25/jul-to-slf4j-1.7.25.jar:/home/huahua/.m2/repository/javax/annotation/javax.annotation-api/1.3.2/javax.annotation-api-1.3.2.jar:/home/huahua/.m2/repository/org/springframework/spring-core/5.1.3.release/spring-core-5.1.3.release.jar:/home/huahua/.m2/repository/org/springframework/spring-jcl/5.1.3.release/spring-jcl-5.1.3.release.jar:/home/huahua/.m2/repository/org/yaml/snakeyaml/1.23/snakeyaml-1.23.jar:/home/huahua/.m2/repository/org/projectlombok/lombok/1.18.4/lombok-1.18.4.jar:/software/ideaide/lib/idea_rt.jar com.feng.spring.springeventmain
connected to the target vm, address: '127.0.0.1:46603', transport: 'socket'
18:37:51.002 [main] debug org.springframework.context.annotation.classpathbeandefinitionscanner - identified candidate component class: file [/home/huahua/ideaprojects/feng/spring-event/target/classes/com/feng/spring/listener/orderedlistener.class]
18:37:51.009 [main] debug org.springframework.context.annotation.classpathbeandefinitionscanner - identified candidate component class: file [/home/huahua/ideaprojects/feng/spring-event/target/classes/com/feng/spring/listener/orderedlistenercopy.class]
18:37:51.017 [main] debug org.springframework.context.annotation.annotationconfigapplicationcontext - refreshing org.springframework.context.annotation.annotationconfigapplicationcontext@37d31475
18:37:51.055 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'org.springframework.context.annotation.internalconfigurationannotationprocessor'
18:37:51.129 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'org.springframework.context.event.internaleventlistenerprocessor'
18:37:51.132 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'org.springframework.context.event.internaleventlistenerfactory'
18:37:51.135 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'org.springframework.context.annotation.internalautowiredannotationprocessor'
18:37:51.136 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'org.springframework.context.annotation.internalcommonannotationprocessor'
18:37:51.145 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'orderedlistener'
18:37:51.154 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'orderedlistenercopy'
my execute step is 555555555555555555555555555
my execute step is 6666666666666666666666666666
disconnected from the target vm, address: '127.0.0.1:46603', transport: 'socket'
process finished with exit code 0
实现了顺序的监听。
2.5 异步监听
spring使用threadpooltaskexecutor来执行异步任务，其实就是schedulingtaskexecutor，使用@enableasync注解@async注解实现异步监听事件的调用
我们来试试
package com.feng.spring.config;
import org.springframework.context.annotation.bean;
import org.springframework.context.annotation.configuration;
import org.springframework.scheduling.concurrent.threadpooltaskexecutor;
import java.util.concurrent.executor;
import java.util.concurrent.threadfactory;
import java.util.concurrent.atomic.atomicinteger;
@configuration
public class asyncconfig {
@bean
public executor initexecutor(){
threadpooltaskexecutor executor = new threadpooltaskexecutor();
//定制线程名称，还可以定制线程group
executor.setthreadfactory(new threadfactory() {
private final atomicinteger threadnumber = new atomicinteger(1);
@override
public thread newthread(runnable r) {
thread t = new thread(thread.currentthread().getthreadgroup(), r,
"async-eventlistener-" + threadnumber.getandincrement(),
0);
return t;
}
});
executor.setcorepoolsize(10);
executor.setmaxpoolsize(20);
executor.setkeepaliveseconds(5);
executor.setqueuecapacity(100);
// executor.setrejectedexecutionhandler(null);
return executor;
}
}
@enableasync
@component
public class testapplicationlistener implements applicationlistener<testspringevent> {
@async
public void onapplicationevent(testspringevent event) {
system.out.println("code is:\t" + event.getcode() + ",\tmessage is:\t" + event.getmessage());
//通过线程group/名称区别
system.out.println(thread.currentthread().getthreadgroup()+ "/" +thread.currentthread().getname());
}
}
执行结果：
/software/jdk1.8.0_191/bin/java -agentlib:jdwp=transport=dt_socket,address=127.0.0.1:44287,suspend=y,server=n -javaagent:/software/ideaide/lib/rt/debugger-agent.jar -dfile.encoding=utf-8 -classpath /software/jdk1.8.0_191/jre/lib/charsets.jar:/software/jdk1.8.0_191/jre/lib/deploy.jar:/software/jdk1.8.0_191/jre/lib/ext/cldrdata.jar:/software/jdk1.8.0_191/jre/lib/ext/dnsns.jar:/software/jdk1.8.0_191/jre/lib/ext/jaccess.jar:/software/jdk1.8.0_191/jre/lib/ext/jfxrt.jar:/software/jdk1.8.0_191/jre/lib/ext/localedata.jar:/software/jdk1.8.0_191/jre/lib/ext/nashorn.jar:/software/jdk1.8.0_191/jre/lib/ext/sunec.jar:/software/jdk1.8.0_191/jre/lib/ext/sunjce_provider.jar:/software/jdk1.8.0_191/jre/lib/ext/sunpkcs11.jar:/software/jdk1.8.0_191/jre/lib/ext/zipfs.jar:/software/jdk1.8.0_191/jre/lib/javaws.jar:/software/jdk1.8.0_191/jre/lib/jce.jar:/software/jdk1.8.0_191/jre/lib/jfr.jar:/software/jdk1.8.0_191/jre/lib/jfxswt.jar:/software/jdk1.8.0_191/jre/lib/jsse.jar:/software/jdk1.8.0_191/jre/lib/management-agent.jar:/software/jdk1.8.0_191/jre/lib/plugin.jar:/software/jdk1.8.0_191/jre/lib/resources.jar:/software/jdk1.8.0_191/jre/lib/rt.jar:/home/huahua/ideaprojects/feng/spring-event/target/classes:/home/huahua/.m2/repository/org/springframework/boot/spring-boot-starter/2.1.1.release/spring-boot-starter-2.1.1.release.jar:/home/huahua/.m2/repository/org/springframework/boot/spring-boot/2.1.1.release/spring-boot-2.1.1.release.jar:/home/huahua/.m2/repository/org/springframework/spring-context/5.1.3.release/spring-context-5.1.3.release.jar:/home/huahua/.m2/repository/org/springframework/spring-aop/5.1.3.release/spring-aop-5.1.3.release.jar:/home/huahua/.m2/repository/org/springframework/spring-beans/5.1.3.release/spring-beans-5.1.3.release.jar:/home/huahua/.m2/repository/org/springframework/spring-expression/5.1.3.release/spring-expression-5.1.3.release.jar:/home/huahua/.m2/repository/org/springframework/boot/spring-boot-autoconfigure/2.1.1.release/spring-boot-autoconfigure-2.1.1.release.jar:/home/huahua/.m2/repository/org/springframework/boot/spring-boot-starter-logging/2.1.1.release/spring-boot-starter-logging-2.1.1.release.jar:/home/huahua/.m2/repository/ch/qos/logback/logback-classic/1.2.3/logback-classic-1.2.3.jar:/home/huahua/.m2/repository/ch/qos/logback/logback-core/1.2.3/logback-core-1.2.3.jar:/home/huahua/.m2/repository/org/slf4j/slf4j-api/1.7.25/slf4j-api-1.7.25.jar:/home/huahua/.m2/repository/org/apache/logging/log4j/log4j-to-slf4j/2.11.1/log4j-to-slf4j-2.11.1.jar:/home/huahua/.m2/repository/org/apache/logging/log4j/log4j-api/2.11.1/log4j-api-2.11.1.jar:/home/huahua/.m2/repository/org/slf4j/jul-to-slf4j/1.7.25/jul-to-slf4j-1.7.25.jar:/home/huahua/.m2/repository/javax/annotation/javax.annotation-api/1.3.2/javax.annotation-api-1.3.2.jar:/home/huahua/.m2/repository/org/springframework/spring-core/5.1.3.release/spring-core-5.1.3.release.jar:/home/huahua/.m2/repository/org/springframework/spring-jcl/5.1.3.release/spring-jcl-5.1.3.release.jar:/home/huahua/.m2/repository/org/yaml/snakeyaml/1.23/snakeyaml-1.23.jar:/home/huahua/.m2/repository/org/projectlombok/lombok/1.18.4/lombok-1.18.4.jar:/software/ideaide/lib/idea_rt.jar com.feng.spring.springeventmain
connected to the target vm, address: '127.0.0.1:44287', transport: 'socket'
19:08:24.692 [main] debug org.springframework.context.annotation.classpathbeandefinitionscanner - identified candidate component class: file [/home/huahua/ideaprojects/feng/spring-event/target/classes/com/feng/spring/config/asyncconfig.class]
19:08:24.730 [main] debug org.springframework.context.annotation.classpathbeandefinitionscanner - identified candidate component class: file [/home/huahua/ideaprojects/feng/spring-event/target/classes/com/feng/spring/listener/testapplicationlistener.class]
19:08:24.741 [main] debug org.springframework.context.annotation.annotationconfigapplicationcontext - refreshing org.springframework.context.annotation.annotationconfigapplicationcontext@37d31475
19:08:24.782 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'org.springframework.context.annotation.internalconfigurationannotationprocessor'
19:08:25.091 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'org.springframework.context.event.internaleventlistenerprocessor'
19:08:25.094 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'org.springframework.context.event.internaleventlistenerfactory'
19:08:25.099 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'org.springframework.context.annotation.internalautowiredannotationprocessor'
19:08:25.100 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'org.springframework.context.annotation.internalcommonannotationprocessor'
19:08:25.106 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'org.springframework.context.annotation.internalasyncannotationprocessor'
19:08:25.109 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'org.springframework.scheduling.annotation.proxyasyncconfiguration'
19:08:25.252 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'asyncconfig'
19:08:25.261 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'testapplicationlistener'
19:08:25.299 [main] debug org.springframework.beans.factory.support.defaultlistablebeanfactory - creating shared instance of singleton bean 'initexecutor'
19:08:25.330 [main] info org.springframework.scheduling.concurrent.threadpooltaskexecutor - initializing executorservice 'initexecutor'
code is: 10000, message is: ---------my spring task event------------
java.lang.threadgroup[name=main,maxpri=10]/async-eventlistener-1
看线程名称，已经异步执行了
[name=main,maxpri=10]/async-eventlistener-1
3. 总结
spring的事件通知demo已经完成，如果需要详细的spring事件从发布到订阅的过程，需要跟踪spring的applicationcontext的publishevent的过程，其实spring的applicationcontext的启动的过程中也定义了很详细的事件，使用intellij idea分析，如下：
spring事件通知的本质：生产者-消费者，体现了设计模式的观察者模式。
以上为个人经验，希望能给大家一个参考，也希望大家多多支持。
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