1. Employee 實體類
class Employee{
private int id;
private String name;
private int age;
public Employee(String name, int age) {
this.name = name;
this.age = age;
}
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;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
2.定義List集合和初始化數據
static List<Employee> empList = new ArrayList<Employee>();
private static void initEmp(){
empList.add(new Employee("張三",30));
empList.add(new Employee("張三1",96));
empList.add(new Employee("張三2",23));
empList.add(new Employee("張三3",69));
empList.add(new Employee("張三4",85));
empList.add(new Employee("張三5",62));
empList.add(new Employee("張三6",12));
empList.add(new Employee("張三7",99));
empList.add(new Employee("張三8",11));
}
3. 獲取員工年齡的最大、最小、總和、平均值
public static void main(String[] args) {
initEmp();
int sum = empList.stream().mapToInt(Employee->Employee.getAge()).sum();
int max = empList.stream().mapToInt(Employee->Employee.getAge()).max().getAsInt();
int min = empList.stream().mapToInt(Employee->Employee.getAge()).min().getAsInt();
double avg = empList.stream().mapToInt(Employee->Employee.getAge()).average().getAsDouble();
System.out.println("最大值:"+max+"\n最小值:"+min+"\n總和:"+sum+"\n平均值:"+avg);
}