Orika的MapperFacade 了解与使用

超、凢脫俗 2022-11-21 03:59 174阅读 0赞

开发中,会出现对象之间的相互转化，或者是根据某一对象转化成另一个对象。  
一般如果手动get和set还是比较费时费力的，此时可以使用Orika的MapperFacade。  
别的方式还有dozer JMapper mapStruck等方式。

效率:因为Orika的设计思路是预先通过javaassist把JavaBean之间的映射关系一次性生成目标拷贝方法代码。 这样就可以避免在Bean 映射环节一次次的读取映射规则。 从而实现效率上的提高。

这里以Springboot集成MapperFactory为实例。

maven包引入  
官网：http://orika-mapper.github.io/orika-docs/intro.html  
<dependency>  
    <groupId>ma.glasnost.orika</groupId>  
    <artifactId>orika-core</artifactId>  
</dependency>

基础概念  
MapperFactory  
MapperFactory mapperFactory = new DefaultMapperFactory.Builder().build();  
MapperFactory用于注册字段映射，配置转换器，自定义映射器等，而我们关注的主要是字段映射这个特性，在下面的小节中会介绍。

MapperFacade  
MapperFacade mapper = mapperFactory.getMapperFacade();  
PersonSource source = new PersonSource();  
PersonDest destination = mapper.map(source, PersonDest.class);  
MapperFacade和spring，apache中的BeanUtils具有相同的地位，负责对象间的映射，也是实际使用中，我们使用的最多的类。

springBoot中的使用

编写容器注入的类

package com.kingboy.springboot.config;
    
    import ma.glasnost.orika.MapperFactory;
    import ma.glasnost.orika.impl.DefaultMapperFactory;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    
    @Configuration
    public class MapperFacotoryAutoWire {
    
        @Bean
        public MapperFactory getFactory(){
            return new DefaultMapperFactory.Builder().build();
        }
    
    }

使用  
基础dto定义

import java.time.LocalDateTime;
    import java.util.Date;
    
    public class Person {
    
        public Person() {
        }
    
        public Person(String name, Integer age, Date dateTime) {
            this.name = name;
            this.age = age;
            this.dateTime = dateTime;
        }
    
        private String name;
    
        private Integer age;
    
        private Date dateTime;
    
        public String getName() {
            return name;
        }
    
        public Person setName(String name) {
            this.name = name;
            return this;
        }
    
        public Integer getAge() {
            return age;
        }
    
        public Person setAge(Integer age) {
            this.age = age;
            return this;
        }
    
        public Date getDateTime() {
            return dateTime;
        }
    
        public Person setDateTime(Date dateTime) {
            this.dateTime = dateTime;
            return this;
        }
    
        @Override
        public String toString() {
            return "Person{" +
                    "name='" + name + '\'' +
                    ", age=" + age +
                    ", dateTime=" + dateTime +
                    '}';
        }
    }

import java.time.LocalDateTime;
    import java.util.Date;
    
    public class Student {
    
        private String name;
    
        private String grade;
    
        private Integer age;
    
        private Date birth;
    
        public Date getBirth() {
            return birth;
        }
    
        public Student setBirth(Date birth) {
            this.birth = birth;
            return this;
        }
    
        public String getName() {
            return name;
        }
    
        public Student setName(String name) {
            this.name = name;
            return this;
        }
    
        public String getGrade() {
            return grade;
        }
    
        public Student setGrade(String grade) {
            this.grade = grade;
            return this;
        }
    
        public Integer getAge() {
            return age;
        }
    
        public Student setAge(Integer age) {
            this.age = age;
            return this;
        }
    
        @Override
        public String toString() {
            return "Student{" +
                    "name='" + name + '\'' +
                    ", grade='" + grade + '\'' +
                    ", age=" + age +
                    ", birth=" + birth +
                    '}';
        }
    }

映射代码

import com.kingboy.springboot.KingBoyApplication;
    import com.kingboy.springboot.domain.Person;
    import com.kingboy.springboot.domain.Student;
    import com.kingboy.springboot.repository.CityRepository;
    import ma.glasnost.orika.MapperFactory;
    import ma.glasnost.orika.metadata.ClassMapBuilder;
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.boot.test.context.SpringBootTest;
    import org.springframework.test.context.junit4.SpringRunner;
    
    import java.time.LocalDateTime;
    import java.util.ArrayList;
    import java.util.Date;
    import java.util.List;
    
    
    @SpringBootTest(classes = KingBoyApplication.class, webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
    @RunWith(SpringRunner.class)
    public class MapperFactoryTest {
    
        @Autowired
        private MapperFactory mapperFactory;
    
        /**
         * 将一个已经存在的类的属性映射到另外一个类上(可以不存在)，直接返回该类，注意必须要有默认构造方法，不然报错
         */
        @Test
        public void copyBeanToBean(){
            Person person = new Person("king", 123, new Date());
            mapperFactory.classMap(Person.class, Student.class)
                    .field("dateTime","birth")//不一样的字段映射
                    .byDefault()//剩余的字段映射
                    .register();
            //如果所有字段一样，则不用写mapperFactory.classMap()方法；
            Student student = mapperFactory.getMapperFacade().map(person, Student.class);
            System.out.println(student);
            //Student{name='king', grade='null', age=123, birth=Thu Apr 13 19:04:43 CST 2017}
        }
    
        /**
         * 将一个List映射到另一个List
         */
    
        @Test
        public void copyListToList(){
            List<Person> personList = getPersonList();
            //手动配置不一样的属性转换
            mapperFactory.classMap(Person.class, Student.class)
                    .field("dateTime","birth")//不一样的字段映射
                    .byDefault()//剩余的字段映射
                    .register();
            //转换List
            List<Student> students = mapperFactory.getMapperFacade().mapAsList(personList, Student.class);
            students.forEach(student -> {
                System.out.println(student);
            });
            /**
             * Student{name='king1', grade='null', age=1, birth=Thu Apr 13 19:10:39 CST 2017}
             *Student{name='king2', grade='null', age=2, birth=Thu Apr 13 19:10:39 CST 2017}
             *Student{name='king3', grade='null', age=3, birth=Thu Apr 13 19:10:39 CST 2017}
             *Student{name='king4', grade='null', age=4, birth=Thu Apr 13 19:10:39 CST 2017}
             *Student{name='king5', grade='null', age=5, birth=Thu Apr 13 19:10:39 CST 2017}
             */
        }
    
        public List<Person> getPersonList(){
            List<Person> list = new ArrayList<>(5);
            Person person1 = new Person("king1", 1, new Date());
            Person person2 = new Person("king2", 2, new Date());
            Person person3 = new Person("king3", 3, new Date());
            Person person4 = new Person("king4", 4, new Date());
            Person person5 = new Person("king5", 5, new Date());
            list.add(person1);
            list.add(person2);
            list.add(person3);
            list.add(person4);
            list.add(person5);
            return list;
        }
    }

参考：

https://blog.csdn.net/kingboyworld/article/details/70161172

如果两个dto属性名称不同怎么办？   
https://blog.csdn.net/liboyang71/article/details/75072995  
https://cloud.tencent.com/developer/article/1110666