spring-boot-starter-actuator doesn't seem to be recognised by one of my properties

Question

I added spring-boot-starter-actuator-2.3.1.RELEASE.jar as an external jar file in my Spring Boot project.

In application.properties I added endpoints.default.web.enabled=true but it has the warning 'endpoints.default.web.enabled' is an unknown property.

When I now run my application and navigate to http://localhost:8080/application I get a 404:

Sun Jun 28 11:01:32 BST 2020
[9ecccfd5] There was an unexpected error (type=Not Found, status=404).
org.springframework.web.server.ResponseStatusException: 404 NOT_FOUND
    at org.springframework.web.reactive.resource.ResourceWebHandler.lambda$handle$0(ResourceWebHandler.java:325)
    Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: 
Error has been observed at the following site(s):
    |_ checkpoint ⇢ org.springframework.web.filter.reactive.HiddenHttpMethodFilter [DefaultWebFilterChain]
    |_ checkpoint ⇢ HTTP GET "/application" [ExceptionHandlingWebHandler]
Stack trace:
        at org.springframework.web.reactive.resource.ResourceWebHandler.lambda$handle$0(ResourceWebHandler.java:325)
        at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:44)
        at reactor.core.publisher.Mono.subscribe(Mono.java:4105)
        at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onComplete(FluxSwitchIfEmpty.java:75)
        at reactor.core.publisher.MonoFlatMap$FlatMapMain.onComplete(MonoFlatMap.java:174)
        at reactor.core.publisher.MonoNext$NextSubscriber.onComplete(MonoNext.java:96)
        at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.drain(FluxConcatMap.java:359)
        at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.onSubscribe(FluxConcatMap.java:211)
        at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:139)
        at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:63)
        at reactor.core.publisher.Mono.subscribe(Mono.java:4105)
        at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.drain(MonoIgnoreThen.java:172)
        at reactor.core.publisher.MonoIgnoreThen.subscribe(MonoIgnoreThen.java:56)
        at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:150)
        at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:67)
        at reactor.core.publisher.MonoNext$NextSubscriber.onNext(MonoNext.java:76)
        at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.innerNext(FluxConcatMap.java:274)
        at reactor.core.publisher.FluxConcatMap$ConcatMapInner.onNext(FluxConcatMap.java:851)
        at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onNext(FluxMapFuseable.java:121)
        at reactor.core.publisher.Operators$ScalarSubscription.request(Operators.java:2186)
        at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.request(FluxMapFuseable.java:162)
        at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.set(Operators.java:1994)
        at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.onSubscribe(Operators.java:1868)
        at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onSubscribe(FluxMapFuseable.java:90)
        at reactor.core.publisher.MonoJust.subscribe(MonoJust.java:54)
        at reactor.core.publisher.Mono.subscribe(Mono.java:4105)
        at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.drain(FluxConcatMap.java:441)
        at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.onSubscribe(FluxConcatMap.java:211)
        at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:139)
        at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:63)
        at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55)
        at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52)
        at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55)
        at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52)
        at reactor.core.publisher.Mono.subscribe(Mono.java:4105)
        at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.drain(MonoIgnoreThen.java:172)
        at reactor.core.publisher.MonoIgnoreThen.subscribe(MonoIgnoreThen.java:56)
        at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55)
        at reactor.netty.http.server.HttpServerHandle.onStateChange(HttpServerHandle.java:64)
        at reactor.netty.tcp.TcpServerBind$ChildObserver.onStateChange(TcpServerBind.java:226)
        at reactor.netty.http.server.HttpServerOperations.onInboundNext(HttpServerOperations.java:441)
        at reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:89)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360)
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352)
        at reactor.netty.http.server.HttpTrafficHandler.channelRead(HttpTrafficHandler.java:167)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360)
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352)
        at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:438)
        at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:326)
        at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:300)
        at io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:253)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360)
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352)
        at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1422)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360)
        at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:931)
        at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163)
        at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:700)
        at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:635)
        at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:552)
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:514)
        at io.netty.util.concurrent.SingleThreadEventExecutor$6.run(SingleThreadEventExecutor.java:1050)
        at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
        at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
        at java.lang.Thread.run(Thread.java:745)

Can anybody tell me what I've done wrong?

Answer 1

Assuming you are using gradle, then the best practice is not to define the spring boot dependency version every time. Rather use something like:

plugins {
  id 'org.springframework.boot' version '2.3.1.RELEASE'
  id 'io.spring.dependency-management' version '1.0.9.RELEASE'
  id 'java'
}

group = 'com.example'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = JavaVersion.VERSION_11

repositories {
  mavenCentral()
}


dependencies {
  implementation 'org.springframework.boot:spring-boot-starter-webflux'
  implementation 'org.springframework.boot:spring-boot-starter-actuator'  

  testImplementation 'org.springframework.boot:spring-boot-starter-test'
 

}

FYI I am using gradle 6.4.1