1. 使用Java原生Map遍历过滤 这种方法适用于所有Java版本,通过遍历Map的entrySet()来获取键值对,然后根据过滤条件检查每个键值对。如果满足条件,则将其添加到新的Map中。 java import java.util.HashMap; import java.util.Map; import java.util.Set; public class FilterMapByKeyExample { public static void mai...
代码: packagecom.example.core.utils.collections;importcom.google.common.collect.Maps;importjava.util.HashMap;importjava.util.Map;importjava.util.Set;importjava.util.stream.Collectors;publicclassFilterMapByKeyTest{publicstaticvoidmain(String[] args){// 过滤生成map<3的数据Map<Integer, String> map =n...
public void filterMapByKeyJava8Lambda () { Mapmap = WEEK.entrySet().stream().filter(r -> r.getKey() <= 3) .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue)); assertThat(map.keySet(), contains(1, 2, 3)); } /** * Google Guava */ @Test public void filterMap...
public void filterMapByKeyGuava () { Map<Integer, String> map = Maps.filterKeys(WEEK, r -> r <= 3); assertThat(map.keySet(), contains(1, 2, 3)); } } filter by value public class FilterMapByValueTest { private Map<Integer, String> WEEK = new HashMap<>(); @Before public void...
*/@TestpublicvoidfilterMapByKeyJava8Lambda () {Map<Integer,String> map =WEEK.entrySet().stream().filter(r -> r.getKey() <=3) .collect(Collectors.toMap(Map.Entry::getKey,Map.Entry::getValue));assertThat(map.keySet(),contains(1,2,3)); ...
voidfilterMapByKey(){Map<Integer,String>map=newHashMap<>();for(Map.Entry<Integer,String>entry:WEEK.entrySet()){if(entry.getKey()<=3){map.put(entry.getKey(),entry.getValue());}}assertThat(map.keySet(),contains(1,2,3));}/*** Java 8 Lambda*/@TestpublicvoidfilterMapByKeyJava8...
Map<Integer, User> filteredMap = usersMap.entrySet() .stream() .filter(entry -> idList.contains(entry.getKey())) .collect(Collectors.toUnmodifiableMap(Map.Entry::getKey, Map.Entry::getValue)); System.out.println(filteredMap); The program output. {1=User(id=1, name=Alex), 3=User(id...
publicvoidfilterMapByKeyJava8Lambda () {Map<Integer,String>map= WEEK.entrySet().stream().filter(r -> r.getKey() <=3) .collect(Collectors.toMap(Map.Entry::getKey,Map.Entry::getValue)); assertThat(map.keySet(), contains(1,2,3)); ...
第一步:创建一个 Map 我们首先需要创建一个样例的 Map。这个 Map 将存储一些名称与相应的分数信息。 importjava.util.HashMap;importjava.util.Map;publicclassMapFilterExample{publicstaticvoidmain(String[]args){// 创建一个 HashMap,存储人名和分数Map<String,Integer>scores=newHashMap<>();scores.put("Alice...
Map<String,Integer>filteredMap=filteredStream.collect(Collectors.toMap(Map.Entry::getKey,Map.Entry::getValue)); 1. 7. 完整代码示例 下面是一个完整的Java Map Filter的代码示例: importjava.util.HashMap;importjava.util.Map;importjava.util.stream.Collectors;importjava.util.stream.Stream;publicclassMap...