public static <T> Map<String, List<Object>> objectList2MapList(List<T> objectList, String[] keyName) throws Exception{ Map<String, List<Object>> resultMap = new HashMap<>(); for(int i = 0; i < keyName.length; i++){ List<Object> arrayList = new ArrayList<>(); for (T t: o...
public static void main(String[] args) { List<Map<String, List<String>>> list = new ArrayList<>(); // 创建测试数据 Map<String, List<String>> map1 = new HashMap<>(); map1.put("key1", Arrays.asList("value1", "value2", "value3")); map1.put("...
public static void main(String[] args) throws Exception { List<String> names = Lists.newArrayList("Answer", "AnswerAIL", "AI"); Map<String, Integer> map = names.stream().collect(Collectors.toMap(v -> v, v -> 1)); System.out.println(map); } } 1. 2. 3. 4. 5. 6. 7. ...
importjava.util.*;importjava.util.function.Function;importjava.util.stream.Collectors;importjava.util.stream.Stream;publicclassListToMapExample{publicstaticvoidmain(String[]args){List<String>list=Arrays.asList("apple","banana","cherry");Map<String,Integer>map=list.stream().collect(Collectors.toMap(F...
我有一个里面有地图的列表,我需要把它变成一个包含列表的地图。我有一个List <Map <String, Object >>,我需要将它更改为Map<String, List <Object<Object>>>。当然,通过传递其中包含的数据,将键与值匹配。对象类中有Date类的对象,使用此结构是因为它是jdbcTemp...
java publicclassTest{publicstaticvoidmain(String[] args){List<Example> list =newArrayList<>();for(longi =1; i <=5; i++) {Example example =newExample();example.setId(newRandom().nextLong());example.setDesc(String.valueOf(example.getId()));list.add(example);}list.forEach(System.out:...
public String getNam return name; } ``` 接下来,我们可以通过以下步骤将List转换为Map对象: 1. 创建一个List对象,并向其中添加Person对象: ```java List<Person> personList = new ArrayList<>(; personList.add(new Person(1, "Alice")); personList.add(new Person(2, "Bob")); personList.add(...
record Employee(int id, String name) { } //创建唯一的员工数据列表 List<Employee> uniqueEmployeeList = new ArrayList<>(); // 创建重复的员工数据列表 List<Employee> duplicateEmployeeList = new ArrayList<>(); //将记录添加到两个列表 2.1. 使用forEach()循环 ...
1）传统⽅法 假设有某个类如下 class Movie { private Integer rank;private String description;public Movie(Integer rank, String description) { super();this.rank = rank;this.description = description;} public Integer getRank() { return rank;} public String getDescription() { return description;}...
常用方式 Map<Integer,String>collect=tagDTOList.stream().collect(Collectors.toMap(TagDTO::getId,TagDTO::getTagName)); 收集成实体本身map Map<Integer,TagDTO>collect=tagDTOList.stream().collect(Collectors.toMap(TagDTO::getId,Function.identity()));Map<Integer,TagDTO>collect=tagDTOList.stream().coll...