933.【开发工具】解决idea：Caused by: java

一、问题背景

启动idea时，报错如下：

Internal error. Please refer to https://jb.gg/ide/critical-startup-errors

com.intellij.ide.plugins.StartupAbortedException: Cannot start app
    at com.intellij.idea.StartupUtil.lambda$start$15(StartupUtil.java:265)
    at java.base/java.util.concurrent.CompletableFuture.uniExceptionally(CompletableFuture.java:990)
    at java.base/java.util.concurrent.CompletableFuture$UniExceptionally.tryFire(CompletableFuture.java:974)
    at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:510)
    at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1773)
    at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.exec(CompletableFuture.java:1760)
    at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:373)
    at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1182)
    at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1655)
    at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1622)
    at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:165)
Caused by: java.net.BindException: Address already in use: bind
    at java.base/sun.nio.ch.Net.bind0(Native Method)
    at java.base/sun.nio.ch.Net.bind(Net.java:555)
    at java.base/sun.nio.ch.ServerSocketChannelImpl.netBind(ServerSocketChannelImpl.java:337)
    at java.base/sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:294)
    at io.netty.channel.socket.nio.NioServerSocketChannel.doBind(NioServerSocketChannel.java:134)
    at io.netty.channel.AbstractChannel$AbstractUnsafe.bind(AbstractChannel.java:562)
    at io.netty.channel.DefaultChannelPipeline$HeadContext.bind(DefaultChannelPipeline.java:1334)
    at io.netty.channel.AbstractChannelHandlerContext.invokeBind(AbstractChannelHandlerContext.java:506)
    at io.netty.channel.AbstractChannelHandlerContext.bind(AbstractChannelHandlerContext.java:491)
    at io.netty.channel.DefaultChannelPipeline.bind(DefaultChannelPipeline.java:973)
    at io.netty.channel.AbstractChannel.bind(AbstractChannel.java:260)
    at io.netty.bootstrap.AbstractBootstrap$2.run(AbstractBootstrap.java:356)
    at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:164)
    at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:469)
    at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:503)
    at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:986)
    at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
    at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
    at java.base/java.lang.Thread.run(Thread.java:833)

-----
Your JRE: 17.0.4.1+7-b469.62 amd64 (JetBrains s.r.o.)
D:\v4_dev_ide\ideaIU-2022.2.3.win\jbr

二、解决方案：

1. 以管理员身份打开 cmd：

   
   

2. 依次执行以下两条命令：

   
   

net stop winnat
net start winnat

3. 再次启动idea，可以发现，问题已经解决了。完美。

这里也还有些地方，暂时还不知道啥原因：1. idea被占用的端口是什么？ 2. net stop winnat的作用是啥？