Maven下载sources时报错java.lang.RuntimeException: Cannot reconnect

1 报错信息

大致报错背景如下:

1. 可以正常导入和更新依赖
2. maven更改过阿里镜像
3. 下载sources会报错，具体堆栈信息如下

java.lang.RuntimeException: Cannot reconnect.
	at org.jetbrains.idea.maven.server.RemoteObjectWrapper.perform(RemoteObjectWrapper.java:82)
	at org.jetbrains.idea.maven.server.MavenEmbedderWrapper.customizeForResolve(MavenEmbedderWrapper.java:38)
	at org.jetbrains.idea.maven.project.MavenProjectResolver.downloadSourcesAndJavadocs(MavenProjectResolver.java:253)
	at org.jetbrains.idea.maven.project.MavenProjectsProcessorArtifactsDownloadingTask.perform(MavenProjectsProcessorArtifactsDownloadingTask.java:40)
	at org.jetbrains.idea.maven.project.MavenProjectsProcessor.doProcessPendingTasks(MavenProjectsProcessor.java:146)
	at org.jetbrains.idea.maven.project.MavenProjectsProcessor$1.run(MavenProjectsProcessor.java:115)
	at org.jetbrains.idea.maven.utils.MavenUtil.lambda$runInBackground$5(MavenUtil.java:518)
	at com.intellij.util.RunnableCallable.call(RunnableCallable.java:20)
	at com.intellij.util.RunnableCallable.call(RunnableCallable.java:11)
	at com.intellij.openapi.application.impl.ApplicationImpl$1.call(ApplicationImpl.java:270)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1$1.run(Executors.java:668)
	at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1$1.run(Executors.java:665)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1.run(Executors.java:665)
	at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.rmi.ConnectException: Connection refused to host: 127.0.0.1; nested exception is: 
	java.net.ConnectException: Connection refused: connect
	at java.rmi/sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:623)
	at java.rmi/sun.rmi.transport.tcp.TCPChannel.createConnection(TCPChannel.java:209)
	at java.rmi/sun.rmi.transport.tcp.TCPChannel.newConnection(TCPChannel.java:196)
	at java.rmi/sun.rmi.server.UnicastRef.invoke(UnicastRef.java:132)
	at java.rmi/java.rmi.server.RemoteObjectInvocationHandler.invokeRemoteMethod(RemoteObjectInvocationHandler.java:217)
	at java.rmi/java.rmi.server.RemoteObjectInvocationHandler.invoke(RemoteObjectInvocationHandler.java:162)
	at com.sun.proxy.$Proxy157.createEmbedder(Unknown Source)
	at jdk.internal.reflect.GeneratedMethodAccessor1731.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at com.intellij.execution.rmi.RemoteUtil.invokeRemote(RemoteUtil.java:150)
	at com.intellij.execution.rmi.RemoteUtil.access$400(RemoteUtil.java:21)
	at com.intellij.execution.rmi.RemoteUtil$1.lambda$invoke$0(RemoteUtil.java:134)
	at com.intellij.openapi.util.ClassLoaderUtil.computeWithClassLoader(ClassLoaderUtil.java:31)
	at com.intellij.execution.rmi.RemoteUtil.executeWithClassLoader(RemoteUtil.java:202)
	at com.intellij.execution.rmi.RemoteUtil$1.invoke(RemoteUtil.java:134)
	at com.sun.proxy.$Proxy157.createEmbedder(Unknown Source)
	at org.jetbrains.idea.maven.server.MavenServerConnector.createEmbedder(MavenServerConnector.java:191)
	at org.jetbrains.idea.maven.server.MavenServerManager$2.create(MavenServerManager.java:344)
	at org.jetbrains.idea.maven.server.MavenServerManager$2.create(MavenServerManager.java:332)
	at org.jetbrains.idea.maven.server.RemoteObjectWrapper.getOrCreateWrappee(RemoteObjectWrapper.java:41)
	at org.jetbrains.idea.maven.server.MavenEmbedderWrapper.doCustomize(MavenEmbedderWrapper.java:79)
	at org.jetbrains.idea.maven.server.MavenEmbedderWrapper.lambda$customizeForResolve$0(MavenEmbedderWrapper.java:39)
	at org.jetbrains.idea.maven.server.RemoteObjectWrapper.perform(RemoteObjectWrapper.java:76)
	... 17 more
Caused by: java.net.ConnectException: Connection refused: connect
	at java.base/java.net.PlainSocketImpl.connect0(Native Method)
	at java.base/java.net.PlainSocketImpl.socketConnect(PlainSocketImpl.java:101)
	at java.base/java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:399)
	at java.base/java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:242)
	at java.base/java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:224)
	at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:403)
	at java.base/java.net.Socket.connect(Socket.java:609)
	at java.base/java.net.Socket.connect(Socket.java:558)
	at java.base/java.net.Socket.<init>(Socket.java:454)
	at java.base/java.net.Socket.<init>(Socket.java:231)
	at com.intellij.execution.rmi.RemoteServer$1.createSocket(RemoteServer.java:122)
	at java.rmi/sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:617)
	... 40 more

2 解决办法

1.添加参数-Djava.net.preferIPv4Stack=true
2.更改JDK为JDK 1.8

具体原因还不清楚，不过添加这参数之后可以解决问题.解决办法是参考开源中国问答得到的，感兴趣可以再看看这篇问答