SpringBoot Application事件监听的实现方案

先说结论

springboot application共支持6种事件监听，按顺序分别是：

1. applicationstartingevent：在spring最开始启动的时候触发
2. applicationenvironmentpreparedevent：在spring已经准备好上下文但是上下文尚未创建的时候触发
3. applicationpreparedevent：在bean定义加载之后、刷新上下文之前触发
4. applicationstartedevent：在刷新上下文之后、调用application命令之前触发
5. applicationreadyevent：在调用applicaiton命令之后触发
6. applicationfailedevent：在启动spring发生异常时触发

另外：

• applicationrunner和commandlinerunner的执行在第五步和第六步之间
• bean的创建在第三步和第四步之间
• 在启动类中，执行springapplication.run()方法后的代码，会在第六步后执行

再上代码：

applicationstartingevent

public class applicationstartingeventlistener implements applicationlistener<applicationstartingevent> {

  @override
  public void onapplicationevent(applicationstartingevent applicationstartingevent) {
    system.out.println("============>>>>> applicationstartingevent is trigged");
    system.out.println(applicationstartingevent.gettimestamp());
    system.out.println("============>>>>> end");
  }
}

applicationenvironmentpreparedevent

public class applicationenvironmentpreparedeventlistener implements applicationlistener<applicationenvironmentpreparedevent> {

  @override
  public void onapplicationevent(applicationenvironmentpreparedevent applicationenvironmentpreparedevent) {
    system.out.println("============>>>>> applicationenvironmentpreparedevent is trigged");
    system.out.println(applicationenvironmentpreparedevent.gettimestamp());
    system.out.println("============>>>>> end");
  }
}

applicationpreparedevent

public class applicationpreparedeventlistener implements applicationlistener<applicationpreparedevent> {

  @override
  public void onapplicationevent(applicationpreparedevent applicationpreparedevent) {
    system.out.println("============>>>>> applicationpreparedevent is trigged");
    system.out.println(applicationpreparedevent.gettimestamp());
    system.out.println("============>>>>> end");
  }
}

applicationstartedevent

public class applicationstartedeventlistener implements applicationlistener<applicationstartedevent> {

  @override
  public void onapplicationevent(applicationstartedevent applicationstartedevent) {
    system.out.println("============>>>>> applicationstartedevent is trigged");
    system.out.println(applicationstartedevent.gettimestamp());
    system.out.println("============>>>>> end");
  }
}

applicationreadyevent

public class applicationreadyeventlistener implements applicationlistener<applicationreadyevent> {

  @override
  public void onapplicationevent(applicationreadyevent applicationreadyevent) {
    system.out.println("============>>>>> applicationreadyevent is trigged");
    system.out.println(applicationreadyevent.gettimestamp());
    system.out.println("============>>>>> end");
  }
}

applicationfailedevent

public class applicationfailedeventlistener implements applicationlistener<applicationfailedevent> {

  @override
  public void onapplicationevent(applicationfailedevent applicationfailedevent) {
    system.out.println("============>>>>> applicationfailedevent is trigged");
    system.out.println(applicationfailedevent.gettimestamp());
    system.out.println("============>>>>> end");
  }
}

主启动类

@springbootapplication
public class springboottestapplication {

  public static void main(string[] args) {
    springapplication springapplication = new springapplication(springboottestapplication.class);
    springapplication.addlisteners(new applicationenvironmentpreparedeventlistener());
    springapplication.addlisteners(new applicationfailedeventlistener());
    springapplication.addlisteners(new applicationpreparedeventlistener());
    springapplication.addlisteners(new applicationreadyeventlistener());
    springapplication.addlisteners(new applicationstartedeventlistener());
    springapplication.addlisteners(new applicationstartingeventlistener());
    springapplication.run(args);
  }
}

运行结果

connected to the target vm, address: '127.0.0.1:62927', transport: 'socket'
============>>>>> applicationstartingevent is trigged
============>>>>> end
============>>>>> applicationenvironmentpreparedevent is trigged
============>>>>> end

 .  ____     _      __ _ _
 /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/ ___)| |_)| | | | | || (_| | ) ) ) )
 ' |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: spring boot ::    (v2.0.3.release)

2018-11-01 14:52:35.117 info 2044 --- [      main] c.l.s.b.test.springboottestapplication  : starting springboottestapplication on edianzu-etgvgb5 with pid 2044 (d:\code\selfcode\springcloud\test\springboottest\target\classes started by administrator in d:\code\selfcode\springcloud)
2018-11-01 14:52:35.122 info 2044 --- [      main] c.l.s.b.test.springboottestapplication  : no active profile set, falling back to default profiles: default
============>>>>> applicationpreparedevent is trigged
============>>>>> end
2018-11-01 14:52:35.212 info 2044 --- [      main] configservletwebserverapplicationcontext : refreshing org.springframework.boot.web.servlet.context.annotationconfigservletwebserverapplicationcontext@3406472c: startup date [thu nov 01 14:52:35 cst 2018]; root of context hierarchy
2018-11-01 14:52:36.891 info 2044 --- [      main] o.s.b.w.embedded.tomcat.tomcatwebserver : tomcat initialized with port(s): 8080 (http)
2018-11-01 14:52:36.920 info 2044 --- [      main] o.apache.catalina.core.standardservice  : starting service [tomcat]
2018-11-01 14:52:36.920 info 2044 --- [      main] org.apache.catalina.core.standardengine : starting servlet engine: apache tomcat/8.5.31
2018-11-01 14:52:36.925 info 2044 --- [ost-startstop-1] o.a.catalina.core.aprlifecyclelistener  : the apr based apache tomcat native library which allows optimal performance in production environments was not found on the java.library.path: [d:\program files\java\jdk1.8.0_191\bin;c:\windows\sun\java\bin;c:\windows\system32;c:\windows;c:\program files (x86)\common files\oracle\java\javapath;c:\program files (x86)\intel\icls client\;c:\program files\intel\icls client\;c:\windows\system32;c:\windows;c:\windows\system32\wbem;c:\windows\system32\windowspowershell\v1.0\;c:\program files (x86)\intel\intel(r) management engine components\dal;c:\program files\intel\intel(r) management engine components\dal;c:\program files (x86)\intel\intel(r) management engine components\ipt;c:\program files\intel\intel(r) management engine components\ipt;c:\program files\intel\wifi\bin\;c:\program files\common files\intel\wirelesscommon\;c:\program files\thinkpad\bluetooth software\;c:\program files\thinkpad\bluetooth software\syswow64;c:\program files (x86)\intel\opencl sdk\2.0\bin\x86;c:\program files (x86)\intel\opencl sdk\2.0\bin\x64;d:\program files\java\jdk1.8.0_191\bin;d:\program files\git\cmd;d:\program files\apache-maven-3.5.4\bin;c:\program files\intel\wifi\bin\;c:\program files\common files\intel\wirelesscommon\;.]
2018-11-01 14:52:37.048 info 2044 --- [ost-startstop-1] o.a.c.c.c.[tomcat].[localhost].[/]    : initializing spring embedded webapplicationcontext
2018-11-01 14:52:37.048 info 2044 --- [ost-startstop-1] o.s.web.context.contextloader      : root webapplicationcontext: initialization completed in 1841 ms
2018-11-01 14:52:37.377 info 2044 --- [ost-startstop-1] o.s.b.w.servlet.servletregistrationbean : servlet dispatcherservlet mapped to [/]
2018-11-01 14:52:37.389 info 2044 --- [ost-startstop-1] o.s.b.w.servlet.filterregistrationbean  : mapping filter: 'characterencodingfilter' to: [/*]
2018-11-01 14:52:37.390 info 2044 --- [ost-startstop-1] o.s.b.w.servlet.filterregistrationbean  : mapping filter: 'hiddenhttpmethodfilter' to: [/*]
2018-11-01 14:52:37.390 info 2044 --- [ost-startstop-1] o.s.b.w.servlet.filterregistrationbean  : mapping filter: 'httpputformcontentfilter' to: [/*]
2018-11-01 14:52:37.390 info 2044 --- [ost-startstop-1] o.s.b.w.servlet.filterregistrationbean  : mapping filter: 'requestcontextfilter' to: [/*]
2018-11-01 14:52:37.598 info 2044 --- [      main] o.s.w.s.handler.simpleurlhandlermapping : mapped url path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.resourcehttprequesthandler]
2018-11-01 14:52:37.857 info 2044 --- [      main] s.w.s.m.m.a.requestmappinghandleradapter : looking for @controlleradvice: org.springframework.boot.web.servlet.context.annotationconfigservletwebserverapplicationcontext@3406472c: startup date [thu nov 01 14:52:35 cst 2018]; root of context hierarchy
2018-11-01 14:52:37.922 info 2044 --- [      main] s.w.s.m.m.a.requestmappinghandlermapping : mapped "{[/error]}" onto public org.springframework.http.responseentity<java.util.map<java.lang.string, java.lang.object>> org.springframework.boot.autoconfigure.web.servlet.error.basicerrorcontroller.error(javax.servlet.http.httpservletrequest)
2018-11-01 14:52:37.923 info 2044 --- [      main] s.w.s.m.m.a.requestmappinghandlermapping : mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.modelandview org.springframework.boot.autoconfigure.web.servlet.error.basicerrorcontroller.errorhtml(javax.servlet.http.httpservletrequest,javax.servlet.http.httpservletresponse)
2018-11-01 14:52:37.973 info 2044 --- [      main] o.s.w.s.handler.simpleurlhandlermapping : mapped url path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.resourcehttprequesthandler]
2018-11-01 14:52:37.973 info 2044 --- [      main] o.s.w.s.handler.simpleurlhandlermapping : mapped url path [/**] onto handler of type [class org.springframework.web.servlet.resource.resourcehttprequesthandler]
2018-11-01 14:52:38.160 info 2044 --- [      main] o.s.j.e.a.annotationmbeanexporter    : registering beans for jmx exposure on startup
2018-11-01 14:52:38.206 info 2044 --- [      main] o.s.b.w.embedded.tomcat.tomcatwebserver : tomcat started on port(s): 8080 (http) with context path ''
2018-11-01 14:52:38.212 info 2044 --- [      main] c.l.s.b.test.springboottestapplication  : started springboottestapplication in 3.976 seconds (jvm running for 5.088)
============>>>>> applicationstartedevent is trigged
============>>>>> end
============>>>>> applicationreadyevent is trigged
============>>>>> end

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