Question

我知道这个问题已在这里被问了几次，但我已经尝试了一切。这可能完全是我的错，因为这是我第一次这样做，但如果是，那么至少我能够改进。

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

我尝试使用connection.disconnet（）来移动方法，但它总是返回此异常。正如我所知，HttpURLConnection.setFixedLengthStreamingMode（）是连接到我尝试使用的API所必需的，否则它将返回HTTP Error 411.

有关如何使其发挥作用的任何想法？

提前感谢您的帮助 - Harieo

Answer 1

在您遇到问题时，只需将connection.getContentLength()替换为requestData.length。

TL; DR。

输入setFixedLengthStreamingMode时，您会发现connected属性已设置为true。好吧，何时将其设置为true？

实际上，already connected意味着您已经更新了HttpURLConnection，这是根本原因。

您应该检查是否编写了以下代码：

connection.getContentType, connection.getContentEncoding

如果这样做，请给他们评论。此方法的实现使用委托模式，这意味着它们将新建另一个HttpURLConnection。

Answer 2

connection.setFixedLengthStreamingMode(connection.getContentLength());

问题出在这里。通过调用getContentLength()，您提交请求并尝试读取响应，然后您尝试设置请求的长度。这没有意义。您需要提供的参数是您要发送的数据量，而不是服务器要发回的数据量。

你还需要写一些东西，再次之前你得到响应代码或做任何意味着获取响应的东西。

正如我所知，连接到我尝试使用的API需要HttpURLConnection.setFixedLengthStreamingMode（），否则它将返回HTTP Error 411。

我看不出你如何判断这段代码。您通过添加setFixedLengthStreamingMode()完成的所有操作都会更改错误。更有可能的问题是你没有发送任何东西。

注意您需要在调用setDoOutput(true)后将请求方法设置为PUT ，因为这会将其设置为POST。

IllegalStateException：已与HttpURLConnection.setFixedLengthStreamingMode连接

2 个答案: