err when build to java

[破耳狼]

Monster.hx:85: characters 23-61 : Int should be Null
Monster.hx:85: characters 23-61 : Int should be Bool
Monster.hx:85: characters 64-65 : Int should be Null
Monster.hx:85: characters 64-65 : Int should be Bool
Monster.hx:135: characters 26-34 : Bool should be Int
Monster.hx:135: characters 26-34 : For function argument 'value'

public function friendly():Null {
var offset:Null = this.bb.__offset(this.bb_pos, 12);
return offset != 0 ? this.bb.readInt8(this.bb_pos + offset) : 0;
}

public static function addFriendly(builder:Builder, friendly:Bool):Void {
builder.addFieldInt8(4, friendly, 0);
}

[破耳狼]

my build.hxml :

-main Monster
-lib flatbuffers
-java java