编写并测试一个代表地址的Address类，地址信息由：国家，省份，城市，街道，邮编组成，并可以返回完

privateStringnational;
privateStringprovincial;
privateStringcity;
privateStringstreet;
privateStringzipcode;
publicAddress(){
}
publicAddress(Stringnational,Stringprovincial,Stringcity,
Stringstreet,Stringzipcode){
super();
this.national=national;
this.provincial=provincial;
this.city=city;
this.street=street;
this.zipcode=zipcode;
}
publicStringtoString(){
return"国家："+this.national+"，省份："+this.provincial+"，城市："
+this.city+"，街道："+this.street+"，邮政编码："+this.zipcode;
}
//setter、getter略
}
publicclassTestDemo{
publicstaticvoidmain(Stringargs[]){
Addressad=newAddress("中国","北京","北京市","MLDN","100088");
System.out.println(ad);
}
}