!177 新增一些工具方法

Merge pull request !177 from easepan/feat/init-with-of
This commit is contained in:
Looly 2020-09-10 11:10:05 +08:00 committed by Gitee
commit dfa0191b36
5 changed files with 96 additions and 0 deletions

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@ -474,4 +474,19 @@ public class ListUtil {
public static <T> List<T> empty() {
return Collections.emptyList();
}
/**
* 像java11一样获取一个List
* @param ts 对象
* @param <T> 对象类型
* @return 不可修改List
*/
public static <T> List<T> of(T... ts) {
if (ArrayUtil.isEmpty(ts)) {
return Collections.emptyList();
}
List<T> unmodifiableList = new ArrayList<>(ts.length);
Collections.addAll(unmodifiableList, ts);
return Collections.unmodifiableList(unmodifiableList);
}
}

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@ -9,6 +9,7 @@ import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Objects;
import java.util.Arrays;
/**
* 比较器链此链包装了多个比较器最终比较结果按照比较器顺序综合多个比较器结果<br>
@ -81,6 +82,26 @@ public class ComparatorChain<E> implements Chain<Comparator<E>, ComparatorChain<
orderingBits = bits;
}
public static <E> ComparatorChain<E> of(Comparator<E> comparator) {
return of(comparator, false);
}
public static <E> ComparatorChain<E> of(Comparator<E> comparator, boolean reverse) {
return new ComparatorChain<>(comparator, reverse);
}
public static <E> ComparatorChain<E> of(Comparator<E>... comparators) {
return of(Arrays.asList(comparators));
}
public static <E> ComparatorChain<E> of(List<Comparator<E>> comparators) {
return new ComparatorChain<>(comparators);
}
public static <E> ComparatorChain<E> of(List<Comparator<E>> comparators, BitSet bits) {
return new ComparatorChain<>(comparators, bits);
}
// -----------------------------------------------------------------------
/**
* 在链的尾部添加比较器使用正向排序

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@ -1,6 +1,10 @@
package cn.hutool.core.comparator;
import java.text.Collator;
import java.util.Comparator;
import java.util.Locale;
import java.util.Objects;
import java.util.function.Function;
/**
* 比较工具类
@ -108,4 +112,34 @@ public class CompareUtil {
return result;
}
/**
* 中文比较器
*
* @param keyExtractor 从对象中提取中文
* @param <T> 对象类型
*
* @return 中文比较器
*/
public static <T> Comparator<T> comparingPinyin(Function<T, String> keyExtractor) {
return comparingPinyin(keyExtractor, false);
}
/**
* 中文比较器
*
* @param keyExtractor 从对象中提取中文
* @param reverse 是否反序
* @param <T> 对象类型
*
* @return 中文比较器
*/
public static <T> Comparator<T> comparingPinyin(Function<T, String> keyExtractor, boolean reverse) {
Objects.requireNonNull(keyExtractor);
PinyinComparator pinyinComparator = new PinyinComparator();
if (reverse) {
return (o1, o2) -> pinyinComparator.compare(keyExtractor.apply(o2), keyExtractor.apply(o1));
}
return (o1, o2) -> pinyinComparator.compare(keyExtractor.apply(o1), keyExtractor.apply(o2));
}
}

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@ -31,6 +31,10 @@ public class Pair<K, V> extends CloneSupport<Pair<K, V>> implements Serializable
this.value = value;
}
public static <K, V> Pair<K, V> of(K key, V value) {
return new Pair<>(key, value);
}
/**
* 获取键
* @return

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@ -1,8 +1,13 @@
package cn.hutool.core.comparator;
import cn.hutool.core.collection.ListUtil;
import org.junit.Assert;
import org.junit.Test;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class CompareUtilTest {
@Test
@ -13,4 +18,21 @@ public class CompareUtilTest {
compare = CompareUtil.compare(null, "a", false);
Assert.assertTrue(compare < 0);
}
@Test
public void comparingPinyin() {
List<String> list = new ArrayList<>();
Collections.addAll(list, "成都", "北京", "上海", "深圳");
List<String> ascendingOrderResult = ListUtil.of("北京", "成都", "上海", "深圳");
List<String> descendingOrderResult = ListUtil.of("深圳", "上海", "成都", "北京");
// 正序
list.sort(CompareUtil.comparingPinyin(e -> e));
Assert.assertEquals(list, ascendingOrderResult);
// 反序
list.sort(CompareUtil.comparingPinyin(e -> e, true));
Assert.assertEquals(list, descendingOrderResult);
}
}