好的，Android的新手。全新安装，Windows 10，具有空活动的基本模板项目。当我启动项目时，它会启动 gradle 同步并开始在我的 gradle 家中生成日志，并显示以下错误
org.gradle.api.UncheckedIOException: java.io.IOException: Unable to establish loopback connection
at org.gradle.internal.UncheckedException.throwAsUncheckedException(UncheckedException.java:43)
at org.gradle.internal.remote.internal.inet.SocketConnection.<init>(SocketConnection.java:60)
at org.gradle.internal.remote.internal.inet.SocketConnectCompletion.create(SocketConnectCompletion.java:39)
at org.gradle.launcher.daemon.server.DaemonTcpServerConnector$1.execute(DaemonTcpServerConnector.java:73)
at org.gradle.launcher.daemon.server.DaemonTcpServerConnector$1.execute(DaemonTcpServerConnector.java:69)
at org.gradle.internal.remote.internal.inet.TcpIncomingConnector$Receiver.run(TcpIncomingConnector.java:112)
at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:54)
at org.gradle.internal.concurrent.StoppableExecutorImpl$1.run(StoppableExecutorImpl.java:40)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.io.IOException: Unable to establish loopback connection
at sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:101)
at sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:68)
at java.security.AccessController.doPrivileged(Native Method)
at sun.nio.ch.PipeImpl.<init>(PipeImpl.java:170)
at sun.nio.ch.SelectorProviderImpl.openPipe(SelectorProviderImpl.java:50)
at java.nio.channels.Pipe.open(Pipe.java:155)
at sun.nio.ch.WindowsSelectorImpl.<init>(WindowsSelectorImpl.java:127)
at sun.nio.ch.WindowsSelectorProvider.openSelector(WindowsSelectorProvider.java:44)
at java.nio.channels.Selector.open(Selector.java:227)
at org.gradle.internal.remote.internal.inet.SocketConnection$SocketInputStream.<init>(SocketConnection.java:142)
at org.gradle.internal.remote.internal.inet.SocketConnection.<init>(SocketConnection.java:58)
... 9 more
Caused by: java.net.SocketException: Permission denied: connect
at sun.nio.ch.Net.connect0(Native Method)
at sun.nio.ch.Net.connect(Net.java:454)
at sun.nio.ch.Net.connect(Net.java:446)
at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:648)
at java.nio.channels.SocketChannel.open(SocketChannel.java:189)
at sun.nio.ch.PipeImpl$Initializer$LoopbackConnector.run(PipeImpl.java:130)
at sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:83)
... 19 more
当我对 gradlew.bat 文件运行基本 gradle 命令时，我遇到了同样的错误，但是当我先运行set _JAVA_OPTIONS=-Djava.net.preferIPv4Stack=true时，它会成功启动守护程序。问题是，我如何使用这些信息使项目的 gradle 同步工作。我尝试将 -Djava.net.preferIPv4Stack=true 添加到 gradle.properties 文件中，尝试将set _JAVA_OPTIONS=-Djava.net.preferIPv4Stack=true添加到项目 gradle 批处理文件中，现在我没有选择。
好吧，终于想通了。我转到环境变量并设置了一个_JAVA_OPTS用户变量，并以 -Djava.net.preferIPv4Stack=true 作为值。