ZhouXY108/hutool
1
0
Fork 0
mirror of https://gitee.com/chinabugotech/hutool.git synced 2025-05-09 23:51:34 +08:00
Code Issues Packages Projects Releases Wiki Activity

CollUtil添加解构collection内部的多个collection为单个list的方法

Browse Source
This commit is contained in:
kongweiguang 2023-06-26 13:44:55 +08:00
parent 7cb8492f18
commit 4e047e98e3
4 changed files with 141 additions and 110 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

45
hutool-core/src/main/java/org/dromara/hutool/core/collection/CollUtil.java
View File

@ -34,6 +34,7 @@ import org.dromara.hutool.core.map.MapUtil;
import org.dromara.hutool.core.reflect.ConstructorUtil;
import org.dromara.hutool.core.reflect.FieldUtil;
import org.dromara.hutool.core.reflect.TypeUtil;
import org.dromara.hutool.core.stream.EasyStream;
import org.dromara.hutool.core.stream.StreamUtil;
import org.dromara.hutool.core.text.StrUtil;
import org.dromara.hutool.core.text.split.SplitUtil;
@ -2354,4 +2355,48 @@ public class CollUtil {
}
return collection.stream().allMatch(predicate);
}
/**
* 结构多层集合
* 例如：List<List<List<String>>> 解构成 List<String>
*
* @param collection 需要解构的集合
* @return 解构后的集合
*/
public static List<Object> flat(Collection<?> collection) {
return flat(collection, true);
}
/**
* 结构多层集合
* 例如：List<List<List<String>>> 解构成 List<String>
* <p>
* skipNull的作用是当集合里面有个值为空，当为true是解构后的集合里面没有null值，如果为false则会在解构后的集合里面有努力了。
*
* @param collection 需要结构的集合
* @param skipNull 是否跳过空的值
* @return 解构后的集合
*/
@SuppressWarnings({"unchecked"})
public static List<Object> flat(Collection<?> collection, boolean skipNull) {
LinkedList queue = EasyStream.of(collection)
.collect(Collectors.toCollection(LinkedList::new));
List<Object> result = new ArrayList<>();
while (!queue.isEmpty()) {
Object t = queue.removeFirst();
if (skipNull && t == null) {
continue;
}
if (t instanceof Collection) {
queue.addAll((Collection<?>) t);
} else {
result.add(t);
}
}
return result;
}
}

43
hutool-core/src/main/java/org/dromara/hutool/core/collection/ListUtil.java
View File

@ -27,7 +27,6 @@ import org.dromara.hutool.core.util.ObjUtil;
import java.util.*;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Predicate;
/**
@ -749,46 +748,4 @@ public class ListUtil {
}
return resList;
}
/**
* 解构list里面的list为单个list
*
* @param list 传入的list集合
* @param <T> 返回的元素类型
* @return 解构后的list集合
*/
public static <T> List<T> flatList(List<?> list) {
return flatList(list, Function.identity());
}
/**
* 解构list里面的list，并可以对每个元素操作
*
* @param list 传入的list集合
* @param operation 对每个元素进行操作
* @param <T> 返回的元素类型
* @param <O> 最内侧的元素类型
* @return 解构后的list集合
*/
@SuppressWarnings("all")
public static <T, O> List<T> flatList(List<?> list, Function<O, T> operation) {
List<T> result = new ArrayList<>();
if (list == null || list.isEmpty()) {
return result;
}
if (list.get(0) instanceof List) {
for (List<?> subList : (List<List<?>>) list) {
result.addAll(flatList(subList, operation));
}
} else {
for (Object item : list) {
result.add(operation.apply((O) item));
}
}
return result;
}
}

48
hutool-core/src/test/java/org/dromara/hutool/core/collection/CollUtilTest.java
View File

@ -3,6 +3,7 @@ package org.dromara.hutool.core.collection;
import org.dromara.hutool.core.collection.iter.IterUtil;
import org.dromara.hutool.core.collection.set.SetUtil;
import org.dromara.hutool.core.comparator.CompareUtil;
import org.dromara.hutool.core.convert.Convert;
import org.dromara.hutool.core.date.DateUtil;
import org.dromara.hutool.core.lang.Console;
import org.dromara.hutool.core.map.Dict;
@ -1181,4 +1182,51 @@ public class CollUtilTest {
public void minNullTest() {
Assertions.assertNull(CollUtil.max(null));
}
@Test
public void flatListTest1() {
List<List<List<String>>> list = Arrays.asList(Arrays.asList(Arrays.asList("1", "2", "3"), Arrays.asList("5", "6", "7")));
List<Object> objects = CollUtil.flat(list);
Assertions.assertArrayEquals(new String[]{"1", "2", "3", "5", "6", "7"}, objects.toArray());
}
@Test
public void flatListTest2() {
List<List<List<String>>> list = Arrays.asList(
Arrays.asList(
Arrays.asList("a"),
Arrays.asList("b", "c"),
Arrays.asList("d", "e", "f")
),
Arrays.asList(
Arrays.asList("g", "h", "i"),
Arrays.asList("j", "k", "l")
)
);
List<Object> flat = CollUtil.flat(list);
Assertions.assertArrayEquals(new String[]{"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l"}, flat.toArray());
}
@Test
void flatListTest3() {
List<List<List<String>>> list = Arrays.asList(
Arrays.asList(
Arrays.asList("a"),
Arrays.asList("b", "c", null),
Arrays.asList("d", "e", "f")
),
Arrays.asList(
Arrays.asList("g", "h", "i"),
Arrays.asList("j", "k", "l")
)
);
List<Object> flat = CollUtil.flat(list, false);
Assertions.assertArrayEquals(new String[]{"a", "b", "c", null, "d", "e", "f", "g", "h", "i", "j", "k", "l"}, flat.toArray());
}
}

19
hutool-core/src/test/java/org/dromara/hutool/core/collection/ListUtilTest.java
View File

@ -2,7 +2,6 @@ package org.dromara.hutool.core.collection;
import lombok.AllArgsConstructor;
import lombok.Data;
import org.dromara.hutool.core.convert.Convert;
import org.dromara.hutool.core.date.StopWatch;
import org.dromara.hutool.core.lang.Console;
import org.dromara.hutool.core.lang.page.PageInfo;
@ -270,22 +269,4 @@ public class ListUtilTest {
ListUtil.reverseNew(list);
}
@Test
public void flatListTest1() {
List<List<List<String>>> list = Arrays.asList(Arrays.asList(Arrays.asList("1", "2", "3"), Arrays.asList("5", "6", "7")));
List<String> objects = ListUtil.flatList(list);
Assertions.assertArrayEquals(new String[]{"1", "2", "3", "5", "6", "7"}, objects.toArray());
}
@Test
public void flatListTest2() {
List<List<List<String>>> list = Arrays.asList(Arrays.asList(Arrays.asList("1", "2", "3"), Arrays.asList("5", "6", "7")));
List<Integer> objects = ListUtil.flatList(list, Convert::toInt);
Assertions.assertArrayEquals(new Integer[]{1, 2, 3, 5, 6, 7}, objects.toArray());
}
}