java - IntelliJ プラグインで「接続が拒否されました」例外を修正する方法

Question

IntelliJ (Community edition 15.0.3) のプラグインをゼロから開発しています。
最初から、以下の例外がありました。

うまくいけば、この警告が表示される理由と修正方法を理解するのに役立つ人がいますか?

エラーメッセージ：

WARN: Connection refused: connect

java.net.ConnectException: Connection refused: connect
    at java.net.DualStackPlainSocketImpl.connect0(Native Method)
    at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
    at java.net.Socket.connect(Socket.java:579)
    at java.net.Socket.connect(Socket.java:528)
    at java.net.Socket.<init>(Socket.java:425)
    at java.net.Socket.<init>(Socket.java:241)
    at com.intellij.idea.SocketLock.tryActivate(SocketLock.java:184)
    at com.intellij.idea.SocketLock.access$300(SocketLock.java:50)
    at com.intellij.idea.SocketLock$2.call(SocketLock.java:124)
    at com.intellij.idea.SocketLock$2.call(SocketLock.java:113)
    at com.intellij.idea.SocketLock.underLocks(SocketLock.java:157)
    at com.intellij.idea.SocketLock.lock(SocketLock.java:113)
    at com.intellij.idea.StartupUtil.lockSystemFolders(StartupUtil.java:263)
    at com.intellij.idea.StartupUtil.prepareAndStart(StartupUtil.java:101)
    at com.intellij.idea.MainImpl.start(MainImpl.java:34)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.intellij.ide.plugins.PluginManager$2.run(PluginManager.java:90)
    at java.lang.Thread.run(Thread.java:744)

MyProjectComponent.java:

import com.intellij.openapi.components.ProjectComponent;
import com.intellij.openapi.project.Project;
import org.jetbrains.annotations.NotNull;

public class MyProjectComponent implements ProjectComponent {

    private Project project;

    public MyProjectComponent(Project project) {
        this.project = project;
    }

    @Override
    public void projectOpened() {
        System.out.println("projectOpened");
    }

    @Override
    public void projectClosed() {
        System.out.println("projectClosed");
    }

    @Override
    public void initComponent() {
        System.out.println("initComponent");
    }

    @Override
    public void disposeComponent() {
        System.out.println("disposeComponent");
    }

    @NotNull
    @Override
    public String getComponentName() {
        return "ProjectComponent";
    }
}