java - 我需要从 Farm 类的 Employee 类中获取最大值

Question

我需要查找并显示农场中工资最高的员工。 这就是我到目前为止所得到的

public class Employee implements Comparable<Employee> {
private String name;
private Integer salary;

public Employee (String name , Integer salary) {
    this.name = name;
    this.salary = salary;
}
public void setName(String name) {
    this.name = name;
}
public String getName() {
    return name;
}
public void setSalary(Integer salary) {
    this.salary = salary;
}
public Integer getSalary() {
    return salary;
}
public String toString() {
    return name + " " + salary;
}
public int compareTo(Employee emp) {
    return this.salary.compareTo(emp.getSalary());
}

}

员工类别

public class Farm {
private String name;
private Integer surface;

List<Employee> emp = new ArrayList<Employee>();


public Farm(String name , Integer surface) {
    this.name =  name;
    this.surface = surface;
}
public void setName(String name) {
    this.name = name;

}
public String getName() {
    return name;
}
public void setSurface(Integer surface) {
    this.surface = surface;
}
public int getSurface () {
    return surface;
}
public String toString() {
    return name + " " + surface;
}
public void makeList(String ename , Integer esalary) {
    this.emp.add(new Employee(ename,esalary));
}
public void getList() {
    for(Employee el : emp)
        System.out.println(el);
}

}

最后一个是主要的。问题是我不知道如何才能拥有更多农场并从每一个农场中获得最大 yield 。你们能帮我吗？

这是我的主应用

public class Mainapp {
public static void main(String args[])
{
    List <Farm> FarmList = new ArrayList<Farm>();
    FarmList.add(new Farm("unirea pizdii", 890030));
    FarmList.add(new Farm("pseudo autsm",78594));
    FarmList.add(new Farm("haha hihi",854856099));

    Farm farm1 = new Farm("Tiguana" , 700);
    farm1.makeList("Mihai", 30000);
    farm1.makeList("Vladimir", 4000);
    farm1.makeList("Tusnic", 3000);
    farm1.getList();


    Employee emp1 =  new Employee(" mihai", 3000);
    System.out.println(emp1);
}

}

Answer 1

要为每个农场获取最高工资的员工，您可以使用流 API:

import static java.util.stream.Collectors.*;

Map<Farm, Optional<Employee>> collect = 
        farmList.stream().collect(groupingBy(Function.identity(),
            flatMapping(farm -> farm.getEmployes().stream(), 
                   maxBy(Employee::compareTo))));

结果映射以Farm为键，以Employee以最高工资为值

注意:flatMapping方法来自java9