文章目录
- java中各种类型用Stream流求最大值最小值
-
- 一、BigDecimal 求最大值和最小值
-
- 1. stream().reduce()实现
- 2. stream().max()或stream().min()实现
- 二、Integer 求最大值和最小值
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- 1. stream().reduce()实现
- 2. Collectors.summarizingInt()实现
- 3. stream().max()或stream().min()实现
- 三、Long 求最大值和最小值
-
- 1. stream().reduce()实现
- 2. Collectors.summarizingLong()实现
- 3. stream().max()或stream().min()实现
- 四、Double 求最大值和最小值
-
- 1. stream().reduce()实现
- 2. Collectors.summarizingLong()实现
- 3. stream().max()或stream().min()实现
java中各种类型用Stream流求最大值最小值
一、BigDecimal 求最大值和最小值
1. stream().reduce()实现
List<BigDecimal> list = new ArrayList<>(Arrays.asList(new BigDecimal("1"), new BigDecimal("2")));
BigDecimal max = list.stream().reduce(list.get(0), BigDecimal::max);
BigDecimal min = list.stream().reduce(list.get(0), BigDecimal::min);
2. stream().max()或stream().min()实现
List<BigDecimal> list = new ArrayList<>(Arrays.asList(new BigDecimal("1"), new BigDecimal("2")));
BigDecimal max = list.stream().max(Comparator.comparing(x -> x)).orElse(null);
BigDecimal min = list.stream().min(Comparator.comparing(x -> x)).orElse(null);
二、Integer 求最大值和最小值
1. stream().reduce()实现
List<Integer> list = new ArrayList<>(Arrays.asList(1, 2));
Integer max = list.stream().reduce(list.get(0), Integer::max);
Integer min = list.stream().reduce(list.get(0), Integer::min);
2. Collectors.summarizingInt()实现
List<Integer> list = new ArrayList<>(Arrays.asList(1, 2));
IntSummaryStatistics intSummaryStatistics = list.stream().collect(Collectors.summarizingInt(x -> x));
Integer max = intSummaryStatistics.getMax();
Integer min = intSummaryStatistics.getMin();
3. stream().max()或stream().min()实现
List<Integer> list = new ArrayList<>(Arrays.asList(1, 2));
Integer max = list.stream().max(Comparator.comparing(x -> x)).orElse(null);
Integer min = list.stream().min(Comparator.comparing(x -> x)).orElse(null);
三、Long 求最大值和最小值
1. stream().reduce()实现
List<Long> list = new ArrayList<>(Arrays.asList(1L, 2L));
Long max = list.stream().reduce(list.get(0), Long::max);
Long min = list.stream().reduce(list.get(0), Long::min);
2. Collectors.summarizingLong()实现
List<Long> list = new ArrayList<>(Arrays.asList(1L, 2L));
LongSummaryStatistics summaryStatistics = list.stream().collect(Collectors.summarizingLong(x -> x));
Long max = summaryStatistics.getMax();
Long min = summaryStatistics.getMin();
3. stream().max()或stream().min()实现
List<Long> list = new ArrayList<>(Arrays.asList(1L, 2L));
Long max = list.stream().max(Comparator.comparing(x -> x)).orElse(null);
Long min = list.stream().min(Comparator.comparing(x -> x)).orElse(null);
四、Double 求最大值和最小值
1. stream().reduce()实现
List<Double> list = new ArrayList<>(Arrays.asList(1d, 2d));
Double max = list.stream().reduce(list.get(0), Double::max);
Double min = list.stream().reduce(list.get(0), Double::min);
2. Collectors.summarizingLong()实现
List<Double> list = new ArrayList<>(Arrays.asList(1d, 2d));
DoubleSummaryStatistics summaryStatistics = list.stream().collect(Collectors.summarizingDouble(x -> x));
Double max = summaryStatistics.getMax();
Double min = summaryStatistics.getMin();
3. stream().max()或stream().min()实现
List<Double> list = new ArrayList<>(Arrays.asList(1d, 2d));
Double max = list.stream().max(Comparator.comparing(x -> x)).orElse(null);
Double min = list.stream().min(Comparator.comparing(x -> x)).orElse(null);
