补充测试用例

hutool-core/src/main/java/cn/hutool/core/stream/EasyStream.java

@@ -197,7 +197,8 @@ public class EasyStream<T> extends AbstractEnhancedWrappedStream<T, EasyStream<T
 	 * @param next 用上一个元素作为参数执行并返回一个新的元素
 	 * @return 无限有序流
 	 */
-	public static <T> EasyStream<T> iterate(final T seed, final Predicate<? super T> hasNext, final UnaryOperator<T> next) {
+	public static <T> EasyStream<T> iterate(final T seed, final Predicate<? super T> hasNext,
+			final UnaryOperator<T> next) {
 		Objects.requireNonNull(next);
 		Objects.requireNonNull(hasNext);
 		return new EasyStream<>(StreamUtil.iterate(seed, hasNext, next));
@@ -240,7 +241,8 @@ public class EasyStream<T> extends AbstractEnhancedWrappedStream<T, EasyStream<T
 	 * @return 拆分后元素组成的流
 	 */
 	public static EasyStream<String> split(final CharSequence str, final String regex) {
-		return Opt.ofBlankAble(str).map(CharSequence::toString).map(s -> s.split(regex)).map(EasyStream::of).orElseGet(EasyStream::empty);
+		return Opt.ofBlankAble(str).map(CharSequence::toString).map(s -> s.split(regex)).map(EasyStream::of)
+				.orElseGet(EasyStream::empty);
 	}
 
 	// --------------------------------------------------------------- Static method end
@@ -272,8 +274,6 @@ public class EasyStream<T> extends AbstractEnhancedWrappedStream<T, EasyStream<T
 	}
 
 
-
-
 	/**
 	 * 计算int类型总和
 	 *
@@ -315,8 +315,32 @@ public class EasyStream<T> extends AbstractEnhancedWrappedStream<T, EasyStream<T
 		return stream.map(mapper).reduce(BigDecimal.ZERO, BigDecimal::add);
 	}
 
+
+	/**
+	 * 计算bigDecimal平均值 并以四舍五入的方式保留2位精度
+	 *
+	 * @param mapper 映射
+	 * @return 如果元素的长度为0 那么会返回为空的opt
+	 */
+	public Opt<BigDecimal> avg(final Function<? super T, BigDecimal> mapper) {
+		return avg(mapper, 2);
+	}
+
+
+	/**
+	 * 计算bigDecimal平均值 并以四舍五入的方式保留scale的进度
+	 *
+	 * @param mapper 映射
+	 * @param scale 精度
+	 * @return 如果元素的长度为0 那么会返回为空的opt
+	 */
+	public Opt<BigDecimal> avg(final Function<? super T, BigDecimal> mapper, int scale) {
+		return avg(mapper, scale, RoundingMode.HALF_UP);
+	}
+
 	/**
 	 * 计算bigDecimal平均值
+	 *
 	 * @param mapper 映射
 	 * @param scale 精度
 	 * @param roundingMode 舍入模式
@@ -329,12 +353,11 @@ public class EasyStream<T> extends AbstractEnhancedWrappedStream<T, EasyStream<T
 			return Opt.ofNullable(null);
 		}
 
-		return Opt.of(EasyStream.of(bigDecimalList).reduce(BigDecimal.ZERO, BigDecimal::add).divide(NumberUtil.toBigDecimal(bigDecimalList.size()),scale, roundingMode));
+		return Opt.of(EasyStream.of(bigDecimalList).reduce(BigDecimal.ZERO, BigDecimal::add)
+				.divide(NumberUtil.toBigDecimal(bigDecimalList.size()), scale, roundingMode));
 	}
 
 
-
-
 	/**
 	 * 计算int平均值
 	 *
@@ -367,7 +390,6 @@ public class EasyStream<T> extends AbstractEnhancedWrappedStream<T, EasyStream<T
 	}
 
 
-
 	/**
 	 * 建造者
 	 *

hutool-core/src/test/java/cn/hutool/core/stream/EasyStreamTest.java

@@ -2,8 +2,10 @@ package cn.hutool.core.stream;
 
 import cn.hutool.core.collection.CollUtil;
 import cn.hutool.core.collection.ListUtil;
+import cn.hutool.core.lang.Opt;
 import cn.hutool.core.map.MapUtil;
 import cn.hutool.core.math.NumberUtil;
+import java.math.RoundingMode;
 import org.junit.Assert;
 import org.junit.Test;
 
@@ -185,7 +187,8 @@ public class EasyStreamTest {
 		Assert.assertEquals(ListUtil.sort(collect2), ListUtil.sort(distinctBy2));
 
 		Assert.assertEquals(
-			4, EasyStream.of(1, 2, 2, null, 3, null).parallel(true).distinct(t -> Objects.isNull(t) ? null : t.toString()).sequential().count()
+				4, EasyStream.of(1, 2, 2, null, 3, null).parallel(true)
+						.distinct(t -> Objects.isNull(t) ? null : t.toString()).sequential().count()
 		);
 	}
 
@@ -440,6 +443,7 @@ public class EasyStreamTest {
 
 	@Test
 	public void testIntSumAndAvg() {
+		//测试int类型的总和
 		int sum = EasyStream.of(1, 2, 3, 4, 5, 6, 7, 8, 9, 10).sum(Integer::intValue);
 		Assert.assertEquals(sum, 55);
 
@@ -447,38 +451,102 @@ public class EasyStreamTest {
 		List<Integer> integerList = new ArrayList<>();
 		int emptySum = EasyStream.of(integerList).sum(Integer::intValue);
 		Assert.assertEquals(emptySum, 0);
+
+		//测试平均值
+		OptionalDouble avg = EasyStream.of(1, 2, 3, 4, 5, 6, 7, 8, 9, 10).avg(Integer::intValue);
+		Assert.assertEquals(avg.getAsDouble(), 5.5, 2);
+
+		//测试元素为空
+		OptionalDouble emptyAvg = EasyStream.of(integerList).avg(Integer::intValue);
+		Assert.assertFalse(emptyAvg.isPresent());
+
 	}
 
 	@Test
 	public void testDoubleSumAndAvg() {
+		//测试double类型的sum
 		double doubleSum = EasyStream.of(1.1, 2.2, 3.3, 4.4, 5.5, 6.6, 7.7, 8.8, 9.9, 10.10).sum(Double::doubleValue);
 		Assert.assertEquals(doubleSum, 59.6, 2);
 
+		//测试double类型的sum 无元素double
 		List<Double> doubleList = new ArrayList<>();
 		double emptySum = EasyStream.of(doubleList).sum(Double::doubleValue);
 		Assert.assertEquals(emptySum, 0.0, 2);
 
+		//测试double类型的avg
+		OptionalDouble doubleAvg = EasyStream.of(1.1, 2.2, 3.3, 4.4, 5.5, 6.6, 7.7, 8.8, 9.9, 10.10)
+				.avg(Double::doubleValue);
+		Assert.assertEquals(doubleAvg.getAsDouble(), 5.96, 2);
+
+		//测试double类型的 空元素的avg
+		OptionalDouble emptyDoubleAvg = EasyStream.of(doubleList).avg(Double::doubleValue);
+		Assert.assertFalse(emptyDoubleAvg.isPresent());
+
 	}
 
 	@Test
 	public void testLongSumAndAvg() {
+		//测试long类型的sum
 		long sum = EasyStream.of(1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L).sum(Long::longValue);
 		Assert.assertEquals(sum, 55);
 
+		//测试long类型的空元素 sum
 		List<Long> longList = new ArrayList<>();
-		double emptySum = EasyStream.of(longList).sum(Long::longValue);
+		long emptySum = EasyStream.of(longList).sum(Long::longValue);
 		Assert.assertEquals(emptySum, 0L);
 
+		//测试long类型的avg
+		OptionalDouble doubleAvg = EasyStream.of(1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L).avg(Long::longValue);
+		Assert.assertEquals(doubleAvg.getAsDouble(), 5.5, 2);
+
+		//测试long类型的avg 空元素
+		OptionalDouble emptyDoubleAvg = EasyStream.of(longList).avg(Long::longValue);
+		Assert.assertFalse(emptyDoubleAvg.isPresent());
+
+
 	}
 
 	@Test
 	public void testBigDecimalSumAndAvg() {
-		BigDecimal sum = EasyStream.of(NumberUtil.toBigDecimal(1.1), NumberUtil.toBigDecimal(2.2), NumberUtil.toBigDecimal(3.3), NumberUtil.toBigDecimal(4.4), NumberUtil.toBigDecimal(5.5), NumberUtil.toBigDecimal(6.6), NumberUtil.toBigDecimal(7.7), NumberUtil.toBigDecimal(8.8), NumberUtil.toBigDecimal(9.9), NumberUtil.toBigDecimal(10.10)).sum(Function.identity());
+		//测试bigDecimal的sum
-		Assert.assertEquals(sum, 59.6);
+		BigDecimal sum = EasyStream.of(NumberUtil.toBigDecimal(1.1), NumberUtil.toBigDecimal(2.2),
+				NumberUtil.toBigDecimal(3.3), NumberUtil.toBigDecimal(4.4), NumberUtil.toBigDecimal(5.5),
+				NumberUtil.toBigDecimal(6.6), NumberUtil.toBigDecimal(7.7), NumberUtil.toBigDecimal(8.8),
+				NumberUtil.toBigDecimal(9.9), NumberUtil.toBigDecimal(10.10)).sum(Function.identity());
+		Assert.assertEquals(sum, NumberUtil.toBigDecimal(59.6));
 
-		List<BigDecimal> bigDecimalList = new ArrayList<>();
+		//测试bigDecimal的sum 空元素
-		BigDecimal emptySum = EasyStream.of(bigDecimalList).sum(Function.identity());
+		List<BigDecimal> bigDecimalEmptyList = new ArrayList<>();
+		BigDecimal emptySum = EasyStream.of(bigDecimalEmptyList).sum(Function.identity());
 		Assert.assertEquals(emptySum, BigDecimal.ZERO);
 
+		//测试bigDecimal的avg
+		Opt<BigDecimal> bigDecimalAvgFullParam = EasyStream.of(NumberUtil.toBigDecimal(1.1),
+						NumberUtil.toBigDecimal(2.2), NumberUtil.toBigDecimal(3.3), NumberUtil.toBigDecimal(4.4),
+						NumberUtil.toBigDecimal(5.5), NumberUtil.toBigDecimal(6.6), NumberUtil.toBigDecimal(7.7),
+						NumberUtil.toBigDecimal(8.8), NumberUtil.toBigDecimal(9.9), NumberUtil.toBigDecimal(10.10))
+				.avg(Function.identity(), 2, RoundingMode.HALF_UP);
+		Assert.assertEquals(bigDecimalAvgFullParam.get(), NumberUtil.toBigDecimal(5.96));
+
+		Opt<BigDecimal> bigDecimalAvgOneParam = EasyStream.of(NumberUtil.toBigDecimal(1.1),
+						NumberUtil.toBigDecimal(2.2), NumberUtil.toBigDecimal(3.3), NumberUtil.toBigDecimal(4.4),
+						NumberUtil.toBigDecimal(5.5), NumberUtil.toBigDecimal(6.6), NumberUtil.toBigDecimal(7.7),
+						NumberUtil.toBigDecimal(8.8), NumberUtil.toBigDecimal(9.9), NumberUtil.toBigDecimal(10.10))
+				.avg(Function.identity());
+		Assert.assertEquals(bigDecimalAvgOneParam.get(), NumberUtil.toBigDecimal(5.96));
+
+		Opt<BigDecimal> bigDecimalAvgTwoParam = EasyStream.of(NumberUtil.toBigDecimal(1.1),
+						NumberUtil.toBigDecimal(2.2), NumberUtil.toBigDecimal(3.3), NumberUtil.toBigDecimal(4.4),
+						NumberUtil.toBigDecimal(5.5), NumberUtil.toBigDecimal(6.6), NumberUtil.toBigDecimal(7.7),
+						NumberUtil.toBigDecimal(8.8), NumberUtil.toBigDecimal(9.9), NumberUtil.toBigDecimal(10.10))
+				.avg(Function.identity(), 2);
+		Assert.assertEquals(bigDecimalAvgTwoParam.get(), NumberUtil.toBigDecimal(5.96));
+
+		//测试bigDecimal的avg 空元素
+		Opt<BigDecimal> emptyBigDecimalAvg = EasyStream.of(bigDecimalEmptyList)
+				.avg(Function.identity(), 2, RoundingMode.HALF_UP);
+		Assert.assertFalse(emptyBigDecimalAvg.isPresent());
+
+
 	}
 }