我知道这个问题在这里已经问过几次了，但是我已经尝试了一切。这可能完全是我的错，因为这是我第一次这样做，但如果这样的话，至少我将能够改进。
相关代码：
URL url = new URL(request);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestProperty("Authorization",
"Bot (token)");
connection.setRequestProperty("User-Agent", "https://discordapp.com/developers/docs/reference, 1.0.0");
connection.setRequestMethod("PUT");
connection.setDoOutput(true);
connection.setFixedLengthStreamingMode(connection.getContentLength());
switch (connection.getResponseCode()) {
case HttpURLConnection.HTTP_OK:
break;
case HttpURLConnection.HTTP_UNAUTHORIZED:
Executor.logger.warning("Connection to Discord API does not have sufficient authorization!");
player.sendMessage(ChatColor.RED
+ "An unrelated error occured in the server, please report this to a staff member.");
return;
default:
Executor.logger.warning(
"An unknown exception occured with the HTTP Error Code: " + connection.getResponseCode());
player.sendMessage(ChatColor.RED + "Linking your accounts has failed!");
TextComponent message = new TextComponent(ChatColor.AQUA + ChatColor.BOLD.toString() + "click here!");
message.setClickEvent(new ClickEvent(ClickEvent.Action.OPEN_URL, "https://www.mcpz.net"));
player.sendMessage(
ChatColor.YELLOW + "For information on how to find your ID, " + message.toPlainText());
return;
}
控制台错误：
org.bukkit.command.CommandException: Unhandled exception executing command 'link' in plugin DiscordBridge v1.0.0
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[squid-spigot.jar:git-Spigot-4af49dc-c5e9a16]
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) ~[squid-spigot.jar:git-Spigot-4af49dc-c5e9a16]
at org.bukkit.craftbukkit.v1_9_R2.CraftServer.dispatchCommand(CraftServer.java:645) ~[squid-spigot.jar:git-Spigot-4af49dc-c5e9a16]
at net.minecraft.server.v1_9_R2.PlayerConnection.handleCommand(PlayerConnection.java:1349) [squid-spigot.jar:git-Spigot-4af49dc-c5e9a16]
at net.minecraft.server.v1_9_R2.PlayerConnection.a(PlayerConnection.java:1184) [squid-spigot.jar:git-Spigot-4af49dc-c5e9a16]
at net.minecraft.server.v1_9_R2.PacketPlayInChat.a(PacketPlayInChat.java:45) [squid-spigot.jar:git-Spigot-4af49dc-c5e9a16]
at net.minecraft.server.v1_9_R2.PacketPlayInChat.a(PacketPlayInChat.java:1) [squid-spigot.jar:git-Spigot-4af49dc-c5e9a16]
at net.minecraft.server.v1_9_R2.PlayerConnectionUtils$1.run(SourceFile:13) [squid-spigot.jar:git-Spigot-4af49dc-c5e9a16]
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.8.0_121]
at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_121]
at net.minecraft.server.v1_9_R2.SystemUtils.a(SourceFile:45) [squid-spigot.jar:git-Spigot-4af49dc-c5e9a16]
at net.minecraft.server.v1_9_R2.MinecraftServer.D(MinecraftServer.java:726) [squid-spigot.jar:git-Spigot-4af49dc-c5e9a16]
at net.minecraft.server.v1_9_R2.DedicatedServer.D(DedicatedServer.java:399) [squid-spigot.jar:git-Spigot-4af49dc-c5e9a16]
at net.minecraft.server.v1_9_R2.MinecraftServer.C(MinecraftServer.java:665) [squid-spigot.jar:git-Spigot-4af49dc-c5e9a16]
at net.minecraft.server.v1_9_R2.MinecraftServer.run(MinecraftServer.java:564) [squid-spigot.jar:git-Spigot-4af49dc-c5e9a16]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_121]
Caused by: java.lang.IllegalStateException: Already connected
at java.net.HttpURLConnection.setFixedLengthStreamingMode(Unknown Source) ~[?:1.8.0_121]
at sun.net.www.protocol.https.HttpsURLConnectionImpl.setFixedLengthStreamingMode(Unknown Source) ~[?:1.8.0_121]
at uk.co.harieo.DBridge.Discord.Broadcaster.responseMinorUpdate(Broadcaster.java:161) ~[?:?]
at uk.co.harieo.DBridge.LinkingCommand.onCommand(LinkingCommand.java:39) ~[?:?]
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[squid-spigot.jar:git-Spigot-4af49dc-c5e9a16]
... 15 more
我试过使用connection.disconnet（）移动方法，但是它总是返回此异常。正如我发现的那样，必须将HttpURLConnection.setFixedLengthStreamingMode（）连接到我尝试使用的API，否则它将返回HTTP错误411。
关于如何使它起作用的任何想法？
感谢您的任何帮助
-哈里欧
最佳答案
connection.setFixedLengthStreamingMode(connection.getContentLength());
问题在这里。通过调用
getContentLength()，您将提交请求并尝试读取响应，然后尝试设置请求的长度。这没有道理。您需要提供的参数是要发送多少数据，而不是服务器要发送回多少数据。您还需要再次编写一些内容，然后才能获得响应代码或执行任何其他隐含获取响应的操作。
正如我发现的那样，必须将HttpURLConnection.setFixedLengthStreamingMode（）连接到我尝试使用的API，否则它将返回HTTP错误411。
我看不出如何用此代码分辨。通过添加
setFixedLengthStreamingMode()完成的所有操作就是更改错误。问题更可能是您没有发送任何东西。注意调用
setDoOutput(true)后，您需要将请求方法设置为PUT，因为它将请求方法设置为POST。