java 队列 pull Java 队列中某个字段求和

一级标题计算java实体列表中某一字段的和

使用java中自带的Collectors.summarizingxxx

首先新建实体

public class ProgramPower {
    private String id;

    private Double count;

##赋值

List<ProgramPower> list=new ArrayList();
        ProgramPower power=new ProgramPower();
        power.setCount(0.9);
        list.add(power);
        ProgramPower power1=new ProgramPower();
        power1.setCount(0.9);
        list.add(power1);
        ProgramPower power2=new ProgramPower();
        power2.setCount(0.9);
        list.add(power2);
     System.out.println(list.stream().collect(Collectors.summarizingDouble(ProgramPower::getCount)));

##打印结果

DoubleSummaryStatistics{count=3, sum=2.700000, min=0.900000, average=0.900000, max=0.900000}

具体的值可以具体获得，如和可以使用getSum()：

list.stream().collect(Collectors.summarizingDouble(ProgramPower::getCount)).getSum()