按多个字段分组统计
map
List<M> collect = ms.stream().collect(Collectors.toMap(k -> k.getG1()+"_"+k.getG2()+"_"+k.getG3(), e -> e, (o1, o2) -> {
o1.setK1(o1.getK1().add(o2.getK1()).setScale(2,BigDecimal.ROUND_HALF_UP));
o1.setK2l(o1.getK2.add(o2.getK2).setScale(2,BigDecimal.ROUND_HALF_UP));
return o1;
})).values().stream().collect(Collectors.toList());
groupBy
public class StringUtil {
public static String format(String value, Object... paras) {
return MessageFormat.format(value, paras);
}
}
Map<String, List<M1>> m1= ms.stream().collect(
Collectors.groupingBy(a -> StringUtil.format("{0}#{1}", a.getG1(),a.getG2())));
List<MaterierlDl> collect1 = new ArrayList<>();
materierlDlMap.forEach((k,v)->{
//如果公司有多个值 需要增加合计行
if(v.size()>=1){
BigDecimal s= v.stream().map(o->o.getK0qmkcje()!=null?o.getK0qmkcje():BigDecimal.ZERO).reduce(BigDecimal.ZERO, BigDecimal::add);
BigDecimal s2 = v.stream().map(o->o.getK0qmkcsl()!=null?o.getK0qmkcsl():BigDecimal.ZERO).reduce(BigDecimal.ZERO, BigDecimal::add);
M hj = new M();
hj.setK1l(stockSlReduce.setScale(0,BigDecimal.ROUND_HALF_UP));
hj.setK2(stockReduce.setScale(0,BigDecimal.ROUND_HALF_UP));
hj.setRadio("0");
collect1.add(hj);
}
});