Java 8.0新增特性（方法引用）

/*
* 静态方法引用:类名::静态方法名
*/
interface IMessage<P, R> {
public R transForm(P p);
}

public class Demo {
public static void main(String[] args) {
IMessage<Integer, String> im = String::valueOf;
System.out.println(im.transForm(1000));
System.out.println(im.transForm(9999).replaceAll("9", "8"));

}
}

/*
* 对象方法引用:实例对象::普通方法
*/
interface IMessage<R> {
public R upper();
}

public class Demo {
public static void main(String[] args) {
// 引用的是 public String toUpperCase();
IMessage<String> i = "Good"::toUpperCase;
System.out.println(i.upper());
}
}

/*
* 特定类型访法引用:特定类::普通方法
*/
interface IMessage<R> {
public int compare(R r1,R r2);
}

public class Demo {
public static void main(String[] args) {
// 引用的是 public int compareTo(String anotherString);
IMessage<String> i = String ::compareTo;
System.out.println(i.compare("A","B"));
}
}

/*
* 构造方法引用:类::new;
*/
interface IMessage<R> {
public R cread(String srt, double num);
}

class Book {
private String title;
private double price;

public Book(String title, double price) {
this.title = title;
this.price = price;
}

@Override
public String toString() {
return "书名:《"+this.title+"》，价格:"+this.price;
}

}

public class Demo {
public static void main(String[] args) {
IMessage<Book>im=Book::new;
Book book=im.cread("Java", 79.6);
System.out.println(book);
}
}