java将员工按薪资是否高于8000分为两部分;将员工按性别分组;将员工按性别和地区分组。代码
时间: 2023-06-09 10:08:13 浏览: 48
答案如下:
按薪资高低分组:
```
List<Employee> highSalaryList = new ArrayList<>();
List<Employee> lowSalaryList = new ArrayList<>();
for(Employee emp : employeeList) {
if(emp.getSalary() > 8000) {
highSalaryList.add(emp);
} else {
lowSalaryList.add(emp);
}
}
```
按性别分组:
```
Map<Gender, List<Employee>> genderMap = employeeList.stream()
.collect(Collectors.groupingBy(Employee::getGender));
```
按性别和地区分组:
```
Map<Gender, Map<String, List<Employee>>> genderRegionMap = employeeList.stream()
.collect(Collectors.groupingBy(Employee::getGender, Collectors.groupingBy(Employee::getRegion)));
```
其中,Employee 类是有性别、地区、薪资等属性的员工类,Gender 是性别枚举类。
相关问题
java将员工按薪资是否高于8000分为两部分;将员工按性别分组;将员工按性别和地区分组。 partitioningBy()、groupingBy()代码
回答:
好的,我知道了。针对您的问题,我可以提供以下的Java代码片段:
1. 将员工按薪资是否高于8000分为两部分:
```
Map<Boolean, List<Employee>> highSalaryMap = employees.stream()
.collect(Collectors.partitioningBy(e -> e.getSalary() > 8000));
```
2. 将员工按性别分组:
```
Map<Gender, List<Employee>> genderMap = employees.stream()
.collect(Collectors.groupingBy(Employee::getGender));
```
3. 将员工按性别和地区分组:
```
Map<Gender, Map<String, List<Employee>>> genderRegionMap = employees.stream()
.collect(Collectors.groupingBy(Employee::getGender,
Collectors.groupingBy(Employee::getRegion)));
```
以上代码中,Employee类是一个具有三个属性(salary, gender, region)的员工实体类。`Collectors`类中的`partitioningBy()`和`groupingBy()`方法可以用来对流进行两种不同类型的分组操作。其中,`partitioningBy()`方法需要传递一个判断条件,对流进行分区操作(true和false两个部分),而`groupingBy()`方法则是按照指定的属性进行分组操作。
将员工先按工资再按年龄升序排序,java
可以使用Java中的Comparator接口和Collections.sort()方法来实现员工先按工资再按年龄升序排序,以下是示例代码:
首先,定义一个Employee类,包含工资和年龄两个属性:
```
public class Employee {
private double salary;
private int age;
public Employee(double salary, int age) {
this.salary = salary;
this.age = age;
}
public double getSalary() {
return salary;
}
public int getAge() {
return age;
}
}
```
然后,定义一个EmployeeComparator类实现Comparator接口,实现compare方法:
```
import java.util.Comparator;
public class EmployeeComparator implements Comparator<Employee> {
@Override
public int compare(Employee e1, Employee e2) {
// 先按工资升序排序
if (e1.getSalary() < e2.getSalary()) {
return -1;
} else if (e1.getSalary() > e2.getSalary()) {
return 1;
} else {
// 如果工资相同再按年龄升序排序
if (e1.getAge() < e2.getAge()) {
return -1;
} else if (e1.getAge() > e2.getAge()) {
return 1;
} else {
return 0;
}
}
}
}
```
最后,在主程序中创建一个Employee列表,使用Collections.sort()方法和EmployeeComparator进行排序:
```
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class Main {
public static void main(String[] args) {
List<Employee> employees = new ArrayList<>();
employees.add(new Employee(6000, 30));
employees.add(new Employee(5000, 25));
employees.add(new Employee(4000, 35));
employees.add(new Employee(5000, 30));
Collections.sort(employees, new EmployeeComparator());
for (Employee e : employees) {
System.out.println("Salary: " + e.getSalary() + ", Age: " + e.getAge());
}
}
}
```
运行结果为:
```
Salary: 4000.0, Age: 35
Salary: 5000.0, Age: 25
Salary: 5000.0, Age: 30
Salary: 6000.0, Age: 30
```