1: 將對象List轉為List<String>

public class user{

    private String name;
    private String password;
    private String address;
    private String age;

 }

List<String> name= user.stream().map(x -> x.getName()).collect(Collectors.toList());

2: 將List<String> 轉為對象list

 List<User> result = staff.stream().map(name-> {
            User user= new User();
            user.setName(name);
            user.setPassword(null);
            user.setAddress(null);
            user.setAge(null);
            return user;
        }).collect(Collectors.toList());

 

3:將一個對象轉為另一個對象

public class UserInfo {
    private String name;
    private String pwd;
}

// 需指定對應字段
List<UserInfo> collect = user.stream()

 .map(l -> new UserInfo(l.getName(), l.getPassword())).collect(Collectors.toList());