1.8
org.projectlombok
lombok
${org.projectlombok.version}
org.mapstruct
mapstruct-processor
${org.mapstruct.version}
关于lombok和mapstruct的版本兼容问题多说几句，maven插件要使用3.6.0版本以上、lombok使用1.16.16版本以上，另外编译的lombok mapstruct的插件不要忘了加上。否则会出现下面的错误：No property named "aaa" exists in source parameter(s). Did you mean "null"?
这种异常就是lombok编译异常导致缺少get setter方法造成的。还有就是缺少构造函数也会抛异常。学习资料：[Java进阶视频资源](()
@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class Student {
private String name;
private int age;
private GenderEnum gender;
private Double height;
private Date birthday;
}
public enum GenderEnum {
Male(“1”, “男”),
Female(“0”, “女”);
private String code;
private String name;
public String getCode() {
return this.code;
}
public String getName() {
return this.name;
}
GenderEnum(String code, String name) {
this.code = code;
this.name = name;
}
}
@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class StudentVO {
private String name;
private int age;
private String gender;
private Double height;
private String birthday;
}
@Mapper
public interface StudentMapper {
StudentMapper INSTANCE = Mappers.getMapper(StudentMapper.class);
@Mapping(source = “gender.name”, target = “gender”)
@Mapping(source = “birthday”, target = “birthday”, dateFormat = “yyyy-MM-dd HH:mm:ss”)
StudentVO student2StudentVO(Student student);
}
实体类是开发过程少不了的，就算是用工具生成肯定也是要有的，需要手写的部分就是这个Mapper的接口，编译完成后会自动生成相应的实现类
然后就可以直接用mapper进行实体的转换了
public class Test {
public static void main(String[] args) {
Student student = Student.builder().name(“小明”).age(6).gender(GenderEnum.Male).height(121.1).birthday(new Date()).build();
System.out.println(student);
//这行代码便是实际要用的代码
StudentVO studentVO = StudentMapper.INSTANCE.studen 《一线大厂Java面试题解析+后端开发学习笔记+最新架构讲解视频+实战项目源码讲义》无偿开源 威信搜索公众号【编程进阶路】 t2StudentVO(student);
System.out.println(studentVO);
}
}
mapper可以进行字段映射，改变字段类型，指定格式化的方式，包括一些日期的默认处理。
可以手动指定格式化的方法：
@Mapper
public interface StudentMapper {
StudentMapper INSTANCE = Mappers.getMapper(StudentMapper.class);
@Mapping(source = “gender”, target = “gender”)
@Mapping(source = “birthday”, target = “birthday”, dateFormat = “yyyy-MM-dd HH:mm:ss”)
StudentVO student2StudentVO(Student student);
default String getGenderName(GenderEnum gender) {
return gender.getName();
}
}
上面只是最简单的实体映射处理，下面介绍一些高级用法
1.List 转换属性映射基于上面的mapping配置
@Mapper
public interface StudentMapper {
StudentMapper INSTANCE = Mappers.getMapper(StudentMapper.class);
@Mapping(source = “gender.name”, target = “gender”)
@Mapping(source = “birthday”, target = “birthday”, dateFormat = “yyyy-MM-dd HH:mm:ss”)
StudentVO student2StudentVO(Student student);
List students2StudentVOs(List studentList);
}
public static void main(String[] args) {
Student student = Student.builder().name(“小明”).age(6).gender(GenderEnum.Male).height(121.1).birthday(new Date()).build();
List list = new ArrayList<>();
list.add(student);
List result = StudentMapper.INSTANCE.students2StudentVOs(list);
System.out.println(result);
}
2.多对象转换到一个对象@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class Student {
private String name;
private int age;
private GenderEnum gender;
private Double height;
private Date birthday;
}
@Data
