ZhouXY108/hutool
1
0
Fork 0
mirror of https://gitee.com/chinabugotech/hutool.git synced 2025-04-19 03:01:48 +08:00
Code Issues Packages Projects Releases Wiki Activity

ListUtil添加解构list内部的多个list为单个list的方法

Browse Source
This commit is contained in:
kongweiguang 2023-06-25 13:59:30 +08:00
parent 095507a86d
commit 7cb8492f18
2 changed files with 71 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

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

@ -27,6 +27,7 @@ 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;
/**
@ -748,4 +749,46 @@ 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;
}
}

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

@ -2,6 +2,7 @@ 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;
@ -269,4 +270,22 @@ 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());
}
}