关于maven项目中

<dependencyManagement>

标签使用的问题

问题描述:

对于pom.xml中<dependencyManagement>使用，我的理解是，子项目需要与父项目中groupId和artifactId对应，才能匹配上版本号。

但是这种情况，子项目只有groupId与父<dependencyManagement>中的groupId匹配上了，artifactId没有匹配上，但却仍然匹配上了了版本号，这是为什么？

具体例子：

父项目：

<dependencyManagement>
 <dependencies>
   <dependency>
     <groupId>org.springframework.cloud</groupId>
     <artifactId>spring-cloud-dependencies</artifactId>
     <version>Greenwich.SR5</version>
     <type>pom</type>
     <scope>import</scope>
   </dependency>
 </dependencies>
</dependencyManagement>

子项目：

<dependencies>
 <dependency>
   <groupId>org.springframework.cloud</groupId>
   <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
 </dependency>
 <dependency>
   <groupId>org.springframework.cloud</groupId>
   <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
 </dependency>
</dependencies>

我的理解是：子项目根据<groupId>org.springframework.cloud</groupId>与父项目<dependencyManagement>中groupId匹配上了，由于父项目中<artifactId>spring-cloud-dependencies</artifactId>里面含有   <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>和

   <artifactId>spring-cloud-starter-netflix-zuul</artifactId>，所以也能匹配上，匹配的版本号就是与父项目<artifactId>spring-cloud-dependencies</artifactId>中对应的

<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>和

   <artifactId>spring-cloud-starter-netflix-zuul</artifactId>，版本号

请老师帮忙解答下？

老师，这里报空指针是为啥呢？

老师，我在进行高可用部署的时候，可以正常运行，并且其他服务也可以正常运行，但是eureka的服务端会爆如下错误(请您有时间的话可以解答一下)：

2023-12-30T20:06:53.437+08:00 ERROR 46409 --- [et_localhost-18] c.n.e.cluster.ReplicationTaskProcessor   : Network level connection to peer localhost; retrying after delay

jakarta.ws.rs.ProcessingException: org.apache.http.conn.HttpHostConnectException: Connect to localhost:8761 [localhost/127.0.0.1, localhost/0:0:0:0:0:0:0:1] failed: Connection refused

at org.glassfish.jersey.apache.connector.ApacheConnector.apply(ApacheConnector.java:531) ~[jersey-apache-connector-3.1.2.jar:na]

at org.glassfish.jersey.client.ClientRuntime.invoke(ClientRuntime.java:300) ~[jersey-client-3.1.2.jar:na]

at org.glassfish.jersey.client.JerseyInvocation.lambda$invoke$0(JerseyInvocation.java:662) ~[jersey-client-3.1.2.jar:na]

at org.glassfish.jersey.client.JerseyInvocation.call(JerseyInvocation.java:697) ~[jersey-client-3.1.2.jar:na]

at org.glassfish.jersey.client.JerseyInvocation.lambda$runInScope$3(JerseyInvocation.java:691) ~[jersey-client-3.1.2.jar:na]

at org.glassfish.jersey.internal.Errors.process(Errors.java:292) ~[jersey-common-3.1.2.jar:na]

at org.glassfish.jersey.internal.Errors.process(Errors.java:274) ~[jersey-common-3.1.2.jar:na]

at org.glassfish.jersey.internal.Errors.process(Errors.java:205) ~[jersey-common-3.1.2.jar:na]

at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:390) ~[jersey-common-3.1.2.jar:na]

at org.glassfish.jersey.client.JerseyInvocation.runInScope(JerseyInvocation.java:691) ~[jersey-client-3.1.2.jar:na]

at org.glassfish.jersey.client.JerseyInvocation.invoke(JerseyInvocation.java:661) ~[jersey-client-3.1.2.jar:na]

at org.glassfish.jersey.client.JerseyInvocation$Builder.method(JerseyInvocation.java:439) ~[jersey-client-3.1.2.jar:na]

at org.glassfish.jersey.client.JerseyInvocation$Builder.post(JerseyInvocation.java:345) ~[jersey-client-3.1.2.jar:na]

at com.netflix.eureka.transport.Jersey3ReplicationClient.submitBatchUpdates(Jersey3ReplicationClient.java:116) ~[eureka-core-jersey3-2.0.1.jar:2.0.1]

at com.netflix.eureka.cluster.ReplicationTaskProcessor.process(ReplicationTaskProcessor.java:80) ~[eureka-core-2.0.1.jar:2.0.1]

at com.netflix.eureka.util.batcher.TaskExecutors$BatchWorkerRunnable.run(TaskExecutors.java:190) ~[eureka-core-2.0.1.jar:2.0.1]

at java.base/java.lang.Thread.run(Thread.java:842) ~[na:na]

Caused by: org.apache.http.conn.HttpHostConnectException: Connect to localhost:8761 [localhost/127.0.0.1, localhost/0:0:0:0:0:0:0:1] failed: Connection refused

at org.apache.http.impl.conn.DefaultHttpClientConnectionOperator.connect(DefaultHttpClientConnectionOperator.java:156) ~[httpclient-4.5.14.jar:4.5.14]

at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.connect(PoolingHttpClientConnectionManager.java:376) ~[httpclient-4.5.14.jar:4.5.14]

at org.apache.http.impl.execchain.MainClientExec.establishRoute(MainClientExec.java:393) ~[httpclient-4.5.14.jar:4.5.14]

at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:236) ~[httpclient-4.5.14.jar:4.5.14]

at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:186) ~[httpclient-4.5.14.jar:4.5.14]

at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:89) ~[httpclient-4.5.14.jar:4.5.14]

at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:110) ~[httpclient-4.5.14.jar:4.5.14]

at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:185) ~[httpclient-4.5.14.jar:4.5.14]

at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:72) ~[httpclient-4.5.14.jar:4.5.14]

at org.glassfish.jersey.apache.connector.ApacheConnector.apply(ApacheConnector.java:483) ~[jersey-apache-connector-3.1.2.jar:na]

... 16 common frames omitted

Caused by: java.net.ConnectException: Connection refused

at java.base/sun.nio.ch.Net.pollConnect(Native Method) ~[na:na]

at java.base/sun.nio.ch.Net.pollConnectNow(Net.java:672) ~[na:na]

at java.base/sun.nio.ch.NioSocketImpl.timedFinishConnect(NioSocketImpl.java:554) ~[na:na]

at java.base/sun.nio.ch.NioSocketImpl.connect(NioSocketImpl.java:602) ~[na:na]

at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:327) ~[na:na]

at java.base/java.net.Socket.connect(Socket.java:633) ~[na:na]

at org.apache.http.conn.socket.PlainConnectionSocketFactory.connectSocket(PlainConnectionSocketFactory.java:75) ~[httpclient-4.5.14.jar:4.5.14]

at org.apache.http.impl.conn.DefaultHttpClientConnectionOperator.connect(DefaultHttpClientConnectionOperator.java:142) ~[httpclient-4.5.14.jar:4.5.14]

... 25 common frames omitted

有没有需要注意的点，我启动成功了，容器也存在，端口也开着，防火墙业关了，但还是访问不到，其他服务比如prometheus可以访问到

服务也启动了，可以访问到8068页面，但页面是空白的，这是哪出问题了

哪些配置可以放在远程配置中心哪些配置放在本地bootstrap?或者说本地最小配置是什么?

老师这个怎么来的

老师键盘按什么键可以选择try catch语句呢

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.getQueryParams()不是获取参数的吗？而Token是保存在Header中的

不是应该用.getHeaders()才能获取到Header中的参数吗？
我用getQueryParams()是获取不到。

这里得TimeUnit.SECONDS.sleep(5)可以换成Thread.sleep(5000);吗

老师 消息是怎么被业务层方法区分类型的呢 上面只是定义的业务层方法名字  那他咋知道具体是哪种消息的呢

老师 码云里面的文件 在获取配置文件时 文件名字以及内容有固定的要求么，我遇到的问题是：我之前取得名字很随便，获取不到报404，用老师的内容和名字后，能获取到，之后发现名字好像有要求 类似xxx-xxx这样的，我自己的application-order就可以，像什么aaa 、 dd 就不可以

老师，我可以问一下我们这个之中的message是怎么获得的嘛