开发工具IntelliJ IDEA如何定义语言和文件类型

package com.simpleplugin;

import com.intellij.lang.Language;

public class SimpleLanguage extends Language {
public static final SimpleLanguage INSTANCE = new SimpleLanguage();

private SimpleLanguage() {
super("Simple");
}
}

package com.simpleplugin;

import com.intellij.openapi.util.IconLoader;

import javax.swing.*;

public class SimpleIcons {
public static final Icon FILE = IconLoader.getIcon("/com/simpleplugin/icons/jar-gray.png");
}

package com.simpleplugin;

import com.intellij.openapi.fileTypes.LanguageFileType;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import javax.swing.*;

public class SimpleFileType extends LanguageFileType {
public static final SimpleFileType INSTANCE = new SimpleFileType();

private SimpleFileType() {
super(SimpleLanguage.INSTANCE);
}

@NotNull
@Override
public String getName() {
return "Simple file";
}

@NotNull
@Override
public String getDescription() {
return "Simple language file";
}

@NotNull
@Override
public String getDefaultExtension() {
return "simple";
}

@Nullable
@Override
public Icon getIcon() {
return SimpleIcons.FILE;
}
}

package com.simpleplugin;

import com.intellij.openapi.fileTypes.FileTypeConsumer;
import com.intellij.openapi.fileTypes.FileTypeFactory;
import org.jetbrains.annotations.NotNull;

public class SimpleFileTypeFactory extends FileTypeFactory{
@Override
public void createFileTypes(@NotNull FileTypeConsumer fileTypeConsumer) {
fileTypeConsumer.consume(SimpleFileType.INSTANCE, "simple");
}
}

<fileTypeFactory implementation="com.simpleplugin.SimpleFileTypeFactory"/>