将 lambda 替换为包含新关键字的方法引用

Question

List<Employee> empListObjDeepCopy = empListRef.stream().map(inv -> new Employee(inv)).collect(Collectors.toList());

如何将此(inv -> new Employee(inv))lambda 替换为方法引用。

完整代码参考：

package org.learn.copy;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;
public class DeepCopy {
public static void main(String[] args){
Employee emp = new Employee();
emp.setName("Hello");
emp.setRollNumber("12345");
Employee emp1 = new Employee();
emp1.setName("Hi");
emp1.setRollNumber("123456");
List<Employee> empList = new ArrayList<>();
empList.add(emp);
empList.add(emp1);
List<Employee> empListRef = empList;
System.out.println("empList Obj: "+empList.get(0).getName());
System.out.println("empListRef Obj: "+empListRef.get(0).getName());
List<Employee> empListObjDeepCopy = empListRef.stream().map(inv -> new Employee(inv)).collect(Collectors.toList());
empListObjDeepCopy.get(0).setName("Hi");
System.out.println("empList Obj: "+empList.get(0).getName());
System.out.println("empListRef Obj: "+empListRef.get(0).getName());
System.out.println("empListObjDeepCopy Obj: "+empListObjDeepCopy.get(0).getName());
}
}
class Employee {
private String name; 
private String rollNumber;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getRollNumber() {
return rollNumber;
}
public void setRollNumber(String rollNumber) {
this.rollNumber = rollNumber;
}
public Employee(Employee employee) {
this.name = employee.name;
this.rollNumber = employee.rollNumber;
}
public Employee() {
super();
}   
}

Answer 1

使用.map(Employee::new)是不明确的，因为您的Employee类中有两个构造函数。 尽量只留下一个。