使用lambda表达式处理集合，返回字典结果

1. 实体类：

@Data
public class Student {
    private String id;
    private String name;
    private BigDecimal scor;

    public Student(String id, String name, BigDecimal scor) {
        this.id = id;
        this.name = name;
        this.scor = scor;
    }
    
}

2. 定义字段类：

@Data
public class Dict {
    private String key;
    private String value;
}

3. 测试Demo

public class DictMapDemo {
    public static void main(String[] args) {
        Student zhang = new Student("1", "zhang", new BigDecimal(10));
        Student li = new Student("2", "li", new BigDecimal(20));
        Student wang = new Student("3", "wang", null);
        List<Student> students = Arrays.asList(zhang, li, wang);
        List<Dict> collect = students.stream().map(x -> {
            Dict dict = new Dict();
            dict.setKey(x.getId());
            dict.setValue(x.getName());
            return dict;
        }).collect(Collectors.toList());
        System.out.println(collect); // [Dict(key=1, value=zhang), Dict(key=2, value=li), Dict(key=3, value=wang)]
    }
}