标签:out 形参 override 列表 return fun pre 举例 构造器
1.构造器引用格式:
类名::new
2.构造器引用使用要求:
和方法引用类似,函数式接口的抽象方法的形参列表和构造器的形参列表一致。抽象方法的返回值类型即为构造器所属的类的类型
3.构造器引用举例:
//Supplier中的T get() //Employee的空参构造器:Employee() @Test public void test1(){ Supplier<Employee> sup = new Supplier<Employee>() { @Override public Employee get() { return new Employee(); } }; System.out.println("*******************"); Supplier<Employee> sup1 = () -> new Employee(); System.out.println(sup1.get()); System.out.println("*******************"); Supplier<Employee> sup2 = Employee :: new; System.out.println(sup2.get()); } //Function中的R apply(T t) @Test public void test2(){ Function<Integer,Employee> func1 = id -> new Employee(id); Employee employee = func1.apply(1001); System.out.println(employee); System.out.println("*******************"); Function<Integer,Employee> func2 = Employee :: new; Employee employee1 = func2.apply(1002); System.out.println(employee1); } //BiFunction中的R apply(T t,U u) @Test public void test3(){ BiFunction<Integer,String,Employee> func1 = (id,name) -> new Employee(id,name); System.out.println(func1.apply(1001,"Tom")); System.out.println("*******************"); BiFunction<Integer,String,Employee> func2 = Employee :: new; System.out.println(func2.apply(1002,"Tom")); }
4.数组引用格式:
数组类型[] :: new
5.数组引用举例:
//Function中的R apply(T t) @Test public void test4(){ Function<Integer,String[]> func1 = length -> new String[length]; String[] arr1 = func1.apply(5); System.out.println(Arrays.toString(arr1)); System.out.println("*******************"); Function<Integer,String[]> func2 = String[] :: new; String[] arr2 = func2.apply(10); System.out.println(Arrays.toString(arr2)); }
java 基本语法(十七)Lambda (四)构造器引用与数组引用
标签:out 形参 override 列表 return fun pre 举例 构造器
原文地址:https://www.cnblogs.com/qiu-hua/p/13196655.html