Stream系列（十二） PartitioningBy方法使用

分割列表

視頻講解: https://www.bilibili.com/video/av78106120/

EmployeeTestCase.java

package com.example.demo;

import lombok.extern.log4j.Log4j2;
import org.junit.Test;

import java.util.DoubleSummaryStatistics;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

@Log4j2
public class EmployeeTestCase extends BaseTestCase {
    @Test
    public void partitioningBy(){
       //把工資大於1500放在true的列表裏,小於或等於1500放在false列表裏
       Map<Boolean, List<Employee>> map = list.stream().collect(Collectors.partitioningBy(employee -> {
           return employee.getSalary() > 1500;
       }));
       log.info("true:{}",map.get(Boolean.TRUE));
       log.info("false:{}",map.get(Boolean.FALSE));
    }
}

BaseTestCase.java

package com.example.demo;

import java.util.Arrays;
import java.util.List;

public class BaseTestCase {
    protected static final List<Employee> list = Arrays.asList(
            new Employee(1, "Alex", 1000),
            new Employee(2, "Michael", 2000),
            new Employee(3, "Jack", 1500),
            new Employee(4, "Owen", 1500),
            new Employee(5, "Denny", 2000));
}

結果:

11:03:43.159 [main] INFO com.example.demo.EmployeeTestCase - true:[Employee(id=2, name=Michael, salary=2000.0), Employee(id=5, name=Denny, salary=2000.0)]
11:03:43.162 [main] INFO com.example.demo.EmployeeTestCase - false:[Employee(id=1, name=Alex, salary=1000.0), Employee(id=3, name=Jack, salary=1500.0), Employee(id=4, name=Owen, salary=1500.0)]

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