SpringBoot中运行代码报错：Null return value from advice does not match primitive return type for: public boolean

代码执行报错：

org.springframework.aop.AopInvocationException: Null return value from advice does not match primitive return type for: public boolean com.itzhimei.service.impl.ITzhimeiServiceImpl.save(java.lang.String,com.itzhimei.ResponseVO,java.lang.String,java.lang.Long)
	at org.springframework.aop.framework.CglibAopProxy.processReturnType(CglibAopProxy.java:391) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
	at org.springframework.aop.framework.CglibAopProxy.access$000(CglibAopProxy.java:84) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
	at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:690) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_181]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_181]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_181]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_181]
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209) [spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136) [spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102) [spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877) [spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783) [spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) [spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991) [spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925) [spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974) [spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:877) [spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:661) [tomcat-embed-core-8.5.32.jar:8.5.32]
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851) [spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) [tomcat-embed-core-8.5.32.jar:8.5.32]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) [tomcat-embed-core-8.5.32.jar:8.5.32]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.32.jar:8.5.32]
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) [tomcat-embed-websocket-8.5.32.jar:8.5.32]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.32.jar:8.5.32]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.32.jar:8.5.32]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.32.jar:8.5.32]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.32.jar:8.5.32]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.32.jar:8.5.32]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.32.jar:8.5.32]

代码中我使用了SpringBoot的异步方法，也就是对应方法上使用了注解：@Async，代码如下：

@Async
public boolean save(参数...) {
	...
}

报错原因：从错误提示可以看出，是因为定义的方法有返回值，而切面处理后没有返回值，二者的返回类型不一致产生的问题，因为Spring中的bean都是代理类来处理的。但实际上是因为异步线程处理时，切面不支持返回类型是基础类型。

解决：将基础类型定义为包装类型，也就是返回类型boolean修改为Boolean。