如何在 Java 中实现带有一个或多个参数的构造函数引用?
java 8object oriented programmingprogramming更新于 2025/4/23 11:37:17
方法引用也适用于 Java 8 中的构造函数。可以使用 classname 和 new 关键字创建 构造函数引用。构造函数引用可以赋值给任何定义了与其兼容方法的 函数式 接口引用。
语法
<Class-Name>::new
Example of Constructor Reference with One Argument
import java.util.function.*;
@FunctionalInterface
interface MyFunctionalInterface {
Student getStudent(String name);
}
public class ConstructorReferenceTest1 {
public static void main(String[] args) {
MyFunctionalInterface mf = Student::new;
Function<Sttring, Student> f1 = Student::new; // Constructor Reference
Function<String, Student> f2 = (name) -> new Student(name);
System.out.println(mf.getStudent("Adithya").getName());
System.out.println(f1.apply("Jai").getName());
System.out.println(f2.apply("Jai").getName());
}
}
// Student class
class Student {
private String name;
public Student(String name) {
this.name = name;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
输出
Adithya Jai Jai
带有两个参数的构造函数引用示例
import java.util.function.*;
@FunctionalInterface
interface MyFunctionalInterface {
Student getStudent(int id, String name);
}
public class ConstructorReferenceTest2 {
public static void main(String[] args) {
MyFunctionalInterface mf = Student::new; // Constructor Reference
BiFunction<Integer, String, Student> f1 = Student::new;
BiFunction<Integer, String, Student> f2 = (id, name) -> new Student(id,name);
System.out.println(mf.getStudent(101, "Adithya").getId());
System.out.println(f1.apply(111, "Jai").getId());
System.out.println(f2.apply(121, "Jai").getId());
}
}
// Student class
class Student {
private int id;
private String name;
public Student(int id, String name) {
this.id = id;
this.name = name;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
输出
101 111 121
