SpringBoot如何进行对象复制的实践

目录

• 为什么需要对象复制
• 对象复制工具类推荐
• Orika基本使用

• 引入依赖

• TC1，基础实体映射
• TC2，实体映射 - 字段转换
• TC3，基础集合映射
• TC4，集合映射 - 字段映射
• TC5，集合与实体映射
• TC6，类类型映射
• TC7，多重映射
• TC8，MyBaits plus分页映射

<dependency>
  <groupId>ma.glasnost.orika</groupId>
  <artifactId>orika-core</artifactId>
  <version>1.5.4</version>
</dependency>

MapperFactory mapperFactory = new DefaultMapperFactory.Builder().build();  

mapperFactory.classMap(SourceClass.class, TargetClass.class)  
   .field("firstName", "givenName")
   .field("lastName", "sirName")
   .byDefault()
   .register();

MapperFacade mapper = mapperFactory.getMapperFacade();
SourceClass source = new SourceClass();  
// set some field values
...
// map the fields of 'source' onto a new instance of PersonDest
TargetClass target = mapper.map(source, TargetClass.class);  

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Student {
    private String id;
    private String name;
    private String email;
}

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Teacher {
    private String id;
    private String name;
    private String emailAddress;
}

/**
 * 只拷贝相同的属性
 */
@Test
public void convertObject(){
  Student student = new Student("1","javadaily","jianzh5@163.com");
  Teacher teacher = OrikaUtils.convert(student, Teacher.class);
  System.out.println(teacher);
}

/**
 * 拷贝不同属性
 */
@Test
public void convertRefObject(){
  Student student = new Student("1","javadaily","jianzh5@163.com");
  Map<String,String> refMap = new HashMap<>(1);
  //map key 放置 源属性，value 放置 目标属性
  refMap.put("email","emailAddress");
  Teacher teacher = OrikaUtils.convert(student, Teacher.class, refMap);
  System.out.println(teacher);
}

/**
  * 只拷贝相同的属性集合
  */
@Test
public void convertList(){
  Student student1 = new Student("1","javadaily","jianzh5@163.com");
  Student student2 = new Student("2","JAVA日知录","jianzh5@xxx.com");
  List<Student> studentList = Lists.newArrayList(student1,student2);
  List<Teacher> teacherList = OrikaUtils.convertList(studentList, Teacher.class);
  System.out.println(teacherList);
}

/**
 * 映射不同属性的集合
 */
@Test
public void convertRefList(){
  Student student1 = new Student("1","javadaily","jianzh5@163.com");
  Student student2 = new Student("2","JAVA日知录","jianzh5@xxx.com");
  List<Student> studentList = Lists.newArrayList(student1,student2);
  Map<String,String> refMap = new HashMap<>(2);
  //map key 放置 源属性，value 放置 目标属性
  refMap.put("email","emailAddress");
  List<Teacher> teacherList = OrikaUtils.convertList(studentList, Teacher.class,refMap);
  System.out.println(teacherList);
}

Map<String,String> refMap = new HashMap<>(2);
refMap.put("email","emailAddress");
List<Teacher> teacherList = OrikaUtils.classMap(Student.class,Teacher.class,refMap)
        .mapAsList(studentList,Teacher.class);

@Data
public class Person {
    private List<String> nameParts;
}

/**
 * 数组和List的映射
 */
@Test
public void convertListObject(){
   Person person = new Person();
   person.setNameParts(Lists.newArrayList("1","javadaily","jianzh5@163.com"));
    Map<String,String> refMap = new HashMap<>(2);
    //map key 放置 源属性，value 放置 目标属性
    refMap.put("nameParts[0]","id");
    refMap.put("nameParts[1]","name");
    refMap.put("nameParts[2]","email");
    Student student = OrikaUtils.convert(person, Student.class,refMap);
    System.out.println(student);
}

@Data
public class BasicPerson {
    private Student student;
}

/**
 * 类类型映射
 */
@Test
public void convertClassObject(){
    BasicPerson basicPerson = new BasicPerson();
    Student student = new Student("1","javadaily","jianzh5@163.com");
    basicPerson.setStudent(student);
    Map<String,String> refMap = new HashMap<>(2);
    //map key 放置 源属性，value 放置 目标属性
    refMap.put("student.id","id");
    refMap.put("student.name","name");
    refMap.put("student.email","emailAddress");
    Teacher teacher = OrikaUtils.convert(basicPerson, Teacher.class,refMap);
    System.out.println(teacher);
}

@Data
public class StudentGrade {
    private String studentGradeName;
    private List<Student> studentList;
}
@Data
public class TeacherGrade {
    private String teacherGradeName;
    private List<Teacher> teacherList;
}

/**
 * 一对多映射
 */
@Test
public void convertComplexObject(){
  Student student1 = new Student("1","javadaily","jianzh5@163.com");
  Student student2 = new Student("2","JAVA日知录","jianzh5@xxx.com");
  List<Student> studentList = Lists.newArrayList(student1,student2);
  StudentGrade studentGrade = new StudentGrade();
  studentGrade.setStudentGradeName("硕士");
  studentGrade.setStudentList(studentList);
  Map<String,String> refMap1 = new HashMap<>(1);
  //map key 放置 源属性，value 放置 目标属性
  refMap1.put("email","emailAddress");
  OrikaUtils.register(Student.class,Teacher.class,refMap1);
  Map<String,String> refMap2 = new HashMap<>(2);
  //map key 放置 源属性，value 放置 目标属性
  refMap2.put("studentGradeName", "teacherGradeName");
  refMap2.put("studentList", "teacherList");
  TeacherGrade teacherGrade = OrikaUtils.convert(studentGrade,TeacherGrade.class,refMap2);
  System.out.println(teacherGrade);
}

public IPage<UserDTO> selectPage(UserDTO userDTO, Integer pageNo, Integer pageSize) {
  Page page = new Page<>(pageNo, pageSize);
  LambdaQueryWrapper<User> query = new LambdaQueryWrapper();
  if (StringUtils.isNotBlank(userDTO.getName())) {
    query.like(User::getKindName,userDTO.getName());
  }
  IPage<User> pageList = page(page,query);
  // 实体转换 SysKind转化为SysKindDto
  Map<String,String> refMap = new HashMap<>(3);
  refMap.put("kindName","name");
  refMap.put("createBy","createUserName");
  refMap.put("createTime","createDate");
  return pageList.convert(item -> OrikaUtils.convert(item, UserDTO.class, refMap));
}