java map

Java流中的MAP操作

Map是流中的⼀个中间操作。返回流。地图法类接受函数类型的参数，下⾯的代码计算流中图书的总价。

在BookStoreFacade类的getTotalPrice⽅法中使⽤map操作返回价格流。Map⽅法返回Stream。然后在Stream上调⽤forEach⽅法来

获取所有书籍的价格之和。

classBook{

privateStringpublisher;

privateStringauthor;

privateStringname;

privatefloatprice;

publicBook(Stringname,Stringauthor,floatprice,

Stringpublisher){

=name;

=author;

=price;

her=publisher;

}

/*Getter-Settermethodsforeachproperty*/

publicfloatgetPrice(){

returnprice;

}

publicStringtoString(){

return"Title:"+name

+",Author:"+author

+",Price:"+price

+",Publisher:"+publisher;

}

}

classBookStoreFacade{

privatefloattotalPrice;

publicfloatgetTotalPrice(StreambookStream){

totalPrice=0;

(b->ce())

.forEach(price->totalPrice+=price);

returntotalPrice;

}

}

classMain{

publicstaticvoidmain(Stringargs[]){

Listbooks=newArrayList<>();

(newBook("Youcanwin","ShivKhera",75,

"BloomsburyPublishing"));

(newBook("IndianEthics","ShyamRanganathan",

2807,"BloomsburyPublishing"));

BookStoreFacadebookstore=newBookStoreFacade();

n("TotalPrice:"

+alPrice(()));

}

}

代码1.流中地图操作的使⽤