在JBox2d中，Vec2.equals()存在如下代码:@Overridepublicbooleanequals(Objectobj){//automaticallygeneratedbyEclipseif(this==obj)returntrue;if(obj==null)returnfalse;if(getClass()!=obj.getClass())returnfalse;Vec2other=(Vec2)obj;if(Float.floatToIntBits(x)!=Float.floatToIntBits(other.x))returnfalse;if(Float.floa