我试图从minecraft发送命令 /arduino一个消息在COM4（我的arduino的端口）消息必须是allesFay我得到了它的工作只是java但不是在minecraft。

这是我的代码（不起作用）

package me.PixelHamster.idk;

import java.io.IOException;
import java.io.PrintWriter;

import javax.comm.SerialPort;

import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.plugin.java.JavaPlugin;

public class Main extends JavaPlugin {

static SerialPort basispoort;

public void onEnable() {
System.out.println("suc6vol aangezet :3");
}

public void onDisable() {
System.out.println("sec6vol afgezet :3");
}

public boolean onCommand(CommandSender zender, Command cmd, String label, String[] argument) {
if (cmd.getName().equalsIgnoreCase("arduino")) {
try {
PrintWriter output = new PrintWriter(basispoort.getOutputStream());
output.print("allesfade");
output.flush();
} catch (IOException e) {

e.printStackTrace();
}




}
return true;
}
}

这是我写的java中的代码。

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.PrintWriter;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import com.fazecast.jSerialComm.SerialPort;

public class Main {

static SerialPort chosenPort;

public static void main(String[] args) {

JFrame window = new JFrame();
window.setTitle("Arduino Kleurenzender");
window.setSize(600, 75);
window.setLayout(new BorderLayout());
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Sound.HAM.play();

JComboBox < String > portList = new JComboBox < String > ();
JComboBox < String > kleurselector = new JComboBox < String > ();
JComboBox < String > wat = new JComboBox < String > ();
JButton connectButton = new JButton("aan");
JPanel topPanel = new JPanel();
topPanel.add(portList);
topPanel.add(kleurselector);
topPanel.add(wat);
topPanel.add(connectButton);
window.add(topPanel, BorderLayout.NORTH);

SerialPort[] portNames = SerialPort.getCommPorts();
for (int i = 0; i < portNames.length; i++)
portList.addItem(portNames[i].getSystemPortName());
kleurselector.addItem("groen");
kleurselector.addItem("geel");
kleurselector.addItem("rood");
kleurselector.addItem("blauw");
kleurselector.addItem("alles");
wat.addItem("aan");
wat.addItem("flikkeren");
wat.addItem("fade");
connectButton.addActionListener(new ActionListener() {
@Override public void actionPerformed(ActionEvent arg0) {
if (connectButton.getText().equals("aan")) {
chosenPort = SerialPort.getCommPort(portList.getSelectedItem().toString());
chosenPort.setComPortTimeouts(SerialPort.TIMEOUT_SCANNER, 0, 0);
if (chosenPort.openPort()) {
connectButton.setText("uit");
portList.setEnabled(false);

Thread thread = new Thread() {
@Override public void run() {

try {
Thread.sleep(100);
} catch (Exception e) {}


PrintWriter output = new PrintWriter(chosenPort.getOutputStream());
while (true) {
output.print(kleurselector.getSelectedItem() + "" + wat.getSelectedItem());
output.flush();
try {
Thread.sleep(2000);
} catch (Exception e) {}
}
}
};
thread.start();
}
} else {
chosenPort.closePort();
portList.setEnabled(true);
connectButton.setText("aan");
}
}
});

window.setVisible(true);
}

}

控制台中的错误

'4/04/2016 21:19:49[INFO]PixelHamster发出服务器命令： /arduino

4/04/2016 21:19:49[ERROR]null

2016年4月4日21:19:49 org.bukkit.命令。命令异常：插件Arduino v1.0.0中执行命令“arduino”的未处理异常

4/04/2016 21:19:49 at org.bukkit.Command.PluginCommand.PluginCommand.java:46）~[spigot 1.9.jar：git-Spiget-7d15d07-c194444]

4/04/2016 21:19:49 at org.bukkit.Command.SimpleCommand dMap.SimpleCommandMap.java:141~[spiget-1.9.jar：git-Spiget-7d15d07-c194444]

4/04/2016 21:19:49 at org.bukkit.craftbukkit.v1_9_R1.CraftServer.调度命令（CraftServer.java:645）~[spiget-1.9.jar：git-Spiget-7d15d07-c194444]

4/04/2016 21:19:49 at net.minecraft.server.v1_9_R1.PlayerConntion.handleCommand（PlayerConnection.java:1302）[spiget-1.9.jar：git-Spiget-7d15d07-c194444]

4/04/2016 21:19:49 at net.minecraft.server.v1_9_R1.PlayerConntion.a（PlayerConnection.java:1137）[spiget-1.9.jar：git-Spiget-7d15d07-c194444]

4/04/2016 21:19:49 at net.minecraft.server.v1_9_R1.PacketPlayInChat.a（PacketPlayInChat.java:45）[spiget-1.9.jar：git-Spiget-7d15d07-c194444]

4/04/2016 21:19:49 at net.minecraft.server.v1_9_R1.PacketPlayInChat.a（PacketPlayInChat.java：1）[spiget-1.9.jar：git-Spiget-7d15d07-c194444]

4/04/2016 21:19:49 at net.minecraft.server.v1_9_R1.PlayerConnectionUtils$1.run（SourceFile：13）[spiget-1.9.jar：git-Spiget-7d15d07-c194444]

4/04/2016 21:19:49 at java.util.conflow.Execator$RunnableAdapter.call（Executors.java:511）[？：1.8.0_31]

4/04/2016 21:19:49 atjava.util.concurrent.FutureTask.run（FutureTask.java:266）[？：1.8.0_31]

4/04/2016 21:19:49 at net.minecraft.server.v1_9_R1.SystemUtils.a（SourceFile：45）[spiget-1.9.jar：git-Spiget-7d15d07-c194444]

4/04/2016 21:19:49 at net.minecraft.server.v1_9_R1.MinecraftServer.D（MinecraftServer.java:716）[spiget-1.9.jar：git-Spiget-7d15d07-c194444]

4/04/2016 21:19:49 at net.minecraft.server.v1_9_R1.DedicatedServer.D（DedicatedServer.java:400）[spiget-1.9.jar：git-Spiget-7d15d07-c194444]

4/04/2016 21:19:49 at net.minecraft.server.v1_9_R1.MinecraftServer.C（MinecraftServer.java:655）[spiget-1.9.jar：git-Spiget-7d15d07-c194444]

4/04/2016 21:19:49 at net.minecraft.server.v1_9_R1.MinecraftServer.run（MinecraftServer.java:554）[spiget-1.9.jar：git-Spiget-7d15d07-c194444]

4/04/2016 21:19:49 atjava.lang.Thread.run（Thread.java:745）[？：1.8.0_31]

2016年4月4日21:19:49由：java.lang.NullPointerException引起

4/04/2016 21:19:49 at me.PixelHamster.idk.Main.onCommand（Main.java:34) ~[?:?]

4/04/2016 21:19:49 at org.bukkit.Command.PluginCommand.PluginCommand.java:44）~[spiget-1.9.jar：git-Spiget-7d15d07-c194444]

4/04/2016 21:19:49…15 more'