added some error handling

DiscordVerifier/src/Main.java

@@ -26,17 +26,20 @@ public class Main extends JavaPlugin {
                             new PrintWriter(s.getOutputStream(), true);
                     BufferedReader in = new BufferedReader(
                             new InputStreamReader(s.getInputStream()));
-                    String inputLine, outputLine;
+                    String inputLine;
                     inputLine = in.readLine();
                     if (inputLine != null) {
-                        outputLine = "test succeeded";
-                        out.println(outputLine);
+
                         System.out.println("message: " + inputLine);
                         String[] info = inputLine.split("\t");
                         Player player = getServer().getPlayer(info[0]);
-                        String code = info[1];
-
-                        send_chat(player, code);
+                        if (player == null){
+                            out.println("PlayerError");
+                        }else {
+                            out.println("success");
+                            String code = info[1];
+                            send_chat(player, code);
+                        }
                     }
                 }
 

cogs/playerlink.py

@@ -0,0 +1,60 @@
+import discord
+from discord.ext import commands
+import random
+import string
+import socket
+
+def get_random_string(length):
+    # Random string with the combination of lower and upper case
+    letters = string.ascii_letters + "0123456789"
+    result_str = ''.join(random.choice(letters) for i in range(length))
+    return result_str
+
+class PlayerError(Exception):
+    pass
+
+def send_chat(minecraftname, code):
+    HOST = '127.0.0.1'  # The server's hostname or IP address
+    PORT = 3333        # The port used by the server
+
+    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+        s.connect((HOST, PORT))
+        s.send(bytes("{}\t{}\n".format(minecraftname, code), encoding="ascii"))
+        data = s.recv(1024)
+        data_string = data.decode("utf-8").strip('\n')
+        if data_string == "PlayerError":
+            raise PlayerError()
+        return True
+
+class PlayerLink(commands.Cog):
+    def __init__(self, client):
+        self.client = client
+
+    @commands.command(name="Link")
+    async def link(self, ctx, arg):
+
+        channelid = ctx.channel.id
+        authorid = ctx.author.id
+        code = get_random_string(8)
+
+        def check(message: discord.Message):
+            return message.channel.id == channelid and message.author.id == authorid
+
+        try:
+            if send_chat(arg, code):
+                await ctx.send("A code has been sent to your minecraft chat in the WorldCraft server.\nSend it in this channel.")
+                msg = await self.client.wait_for('message', check=check)
+                if msg.content == code:
+                    await ctx.send("The link was successfull")
+                else:
+                    await ctx.send("Wrong code")
+
+        except PlayerError:
+            await ctx.send("Player '" + arg + "' not found")
+        except:
+            await ctx.send("Something went wrong")
+
+
+
+def setup(client):
+    client.add_cog(PlayerLink(client))