15);User u3=newUser("laoBi",20);User u4=newUser("wangHao",20);list.add(u1);list.add(u2);list.add(u3);list.add(u4);staticclassUser{privateString name;privateint age;publicUser(String name,int age){this.name=name;this.age=age;}publicStringgetName(){returnname;}publicvoid...
Set<String>set=newHashSet<>();set.add("A");set.add("B");set.add("C");Map<Integer,String>map=newHashMap<>();intindex=0;for(Stringstr:set){map.put(index++,str);} Set转JSON Set<String>set=newHashSet<>();set.add("A");set.add("B");set.add("C");Stringjson=newGson()....
Map<String, List<String>> map =list.stream().collect(Collectors.toMap(Person::getId, p->{ List<String> getNameList =newArrayList<>(); getNameList.add(p.getName());returngetNameList; }, (List<String> value1, List<String> value2) ->{ value1.addAll(value2);returnvalue1; } )) 3...
Map<String, User> map = users.stream().collect(Collectors.toMap(user -> String.valueof(user.getId() + user.getUserName()), Function.identity())); 3、以ID为Key,deptId为Value构建Map(id或deptId为NULL时报错) Map<Long, Long> map = users.stream().collect(Collectors.toMap(User::getId, User...
Java List转map java list转map<string,list>,//实体类publicclassStudent{privateStringno;//学号privateStringname;//姓名//构造方法忽略//set、get方法忽略}publicclassTeacher{privateStringno;//教师号privateStringnam
Set<String> set2 = new TreeSet<>(list); // 使用 TreeSet 转换 1. 2. 3. 4. 5. 6. 7. 🎉 Set 转 List Set 转 List 可以使用ArrayList或LinkedList来实现。 Set<String> set = new HashSet<>(); set.add("Alice"); set.add("Bob"); ...
.toMap(ke -> String.valueOf(ke.getId()),v -> v.getName(),(k1,k2) -> k1));/*** 检验是否转map成功 ***///遍历方法一//获取map中的key键名的set集合Set<String> ketSet = map.keySet();// 得到迭代器Iterator<String> iterator = ketSet.iterator();//使用Lambda方式输出iterator.for...
1 将一个实体类的list集合转为map学生实体类：package test;public class Student {private Long id; private String age; public Long getId() { return id; } public void setId(Long id) { this.id = id; } public String getAge() { return age; } public void setAge(...
();//方式一Map<String, String> stringMap = stuList.stream().collect(Collectors.toMap(v -> String.valueOf(v.getId()), v -> v.getName()));//方式二Map<Long, String> stringMap2 = stuList.stream().collect(Collectors.toMap(Stu::getId, Stu::getName));//转换成map的时候,可能出现key...
将List<Map<String, Object>>转换为List<Map<String, String>>可以通过遍历原始列表,逐个处理每个Map对象的值,并将其转换为String类型。下面是一个示例代码: 代码语言:txt 复制 import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; public clas...