MapStruct入门及集成springboot

1、引入依赖

maven的pom.xml

...
<properties>
    <org.mapstruct.version>1.4.2.Final</org.mapstruct.version>
</properties>
...
<dependencies>
    <dependency>
        <groupId>org.mapstruct</groupId>
        <artifactId>mapstruct</artifactId>
        <version>${org.mapstruct.version}</version>
    </dependency>
</dependencies>
...
<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.8.1</version>
            <configuration>
                <source>1.8</source> <!-- depending on your project -->
                <target>1.8</target> <!-- depending on your project -->
                <annotationProcessorPaths>
                    <path>
                        <groupId>org.mapstruct</groupId>
                        <artifactId>mapstruct-processor</artifactId>
                        <version>${org.mapstruct.version}</version>
                    </path>
                    <!-- other annotation processors -->
                </annotationProcessorPaths>
            </configuration>
        </plugin>
    </plugins>
</build>
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或


    1.4.2.Final



    org.mapstruct
    mapstruct
    ${org.mapstruct.version}



    org.mapstruct
    mapstruct-processor
    ${org.mapstruct.version}

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2、简单示例

2.1 新增实体

admin 实体：

public class Admin {

    private String name;

    private String address;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }
}
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user实体：

public class User {

    private String name;

    private String address;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }
}
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2.2 定义mapper

mapper:

import org.mapstruct.Mapper;
import org.mapstruct.factory.Mappers;

@Mapper
public interface UserMapper {

    UserMapper INSTANCE  = Mappers.getMapper(UserMapper.class);

    Admin userToAdmin(User user);
}
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2.3 测试效果

测试demo：

public static void main(String[] args) {
        User user = new User();
        user.setAddress("213");
        user.setName("张三");
        Admin admin = UserMapper.INSTANCE.userToAdmin(user);
        System.out.println(admin.getAddress());
        System.out.println(admin.getName());
    }
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结果：

3、多个入参构造一个对象

3.1 新增实体

Role:

public class Role {

    private String name;

    private String roleId;

    private String description;

    public Role() {
    }

    public Role(String name, String roleId, String description) {
        this.name = name;
        this.roleId = roleId;
        this.description = description;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getRoleId() {
        return roleId;
    }

    public void setRoleId(String roleId) {
        this.roleId = roleId;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }
}
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User:

public class User {

    private Long userId;

    private String name;

    private String address;

    public User() {
    }

    public User(Long userId, String name, String address) {
        this.userId = userId;
        this.name = name;
        this.address = address;
    }

    public Long getUserId() {
        return userId;
    }

    public void setUserId(Long userId) {
        this.userId = userId;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }
}
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UserRoleDTO:

public class UserRoleDTO {

    private Long id;

    private String name;

    private String address;

    private String roleName;

    private String roleId;

    private String description;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getRoleName() {
        return roleName;
    }

    public void setRoleName(String roleName) {
        this.roleName = roleName;
    }

    public String getRoleId() {
        return roleId;
    }

    public void setRoleId(String roleId) {
        this.roleId = roleId;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    @Override
    public String toString() {
        return "UserRoleDTO{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", address='" + address + '\'' +
                ", roleName='" + roleName + '\'' +
                ", roleId='" + roleId + '\'' +
                ", description='" + description + '\'' +
                '}';
    }
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3.2 定义mapper

mapper:

import org.mapstruct.Mapper;
import org.mapstruct.Mapping;
import org.mapstruct.Mappings;
import org.mapstruct.factory.Mappers;

@Mapper
public interface UserMapper {

    UserMapper INSTANCE  = Mappers.getMapper(UserMapper.class);

    @Mappings({
            //user中的userId绑定到目标对象的id属性中
            @Mapping(source = "user.userId", target = "id"),
            //user和 role中都有name属性，所以需要指定一个来传给UserRoleDto
            @Mapping(source = "user.name",target = "name")

    })
    UserRoleDTO toUserRoleDTO(User user, Role role);
}
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3.3 测试效果

测试demo：

public static void main(String[] args) {
        User user = new User(1L, "小王八蛋", "北京");
        Role role = new Role("管理员", "2", "描述");
        UserRoleDTO userRoleDTO = UserMapper.INSTANCE.toUserRoleDTO(user, role);
        System.out.println(userRoleDTO.toString());
    }
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结果：

UserRoleDTO{id=1, name='小王八蛋', address='北京', roleName='null', roleId='2', description='描述'}
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4、数据类型转换（int -> string 等）

4.1 新增实体

product：

import java.util.Date;

public class Product {

    private int price;

    private int stock;

    private Date saleTime;

    private Date validTime;

    public Product() {
    }

    public Product(int price, int stock, Date saleTime, Date validTime) {
        this.price = price;
        this.stock = stock;
        this.saleTime = saleTime;
        this.validTime = validTime;
    }

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    public int getStock() {
        return stock;
    }

    public void setStock(int stock) {
        this.stock = stock;
    }

    public Date getSaleTime() {
        return saleTime;
    }

    public void setSaleTime(Date saleTime) {
        this.saleTime = saleTime;
    }

    public Date getValidTime() {
        return validTime;
    }

    public void setValidTime(Date validTime) {
        this.validTime = validTime;
    }
}

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productDTO:

public class ProductDTO {

    private String price;

    private String stock;

    private String saleTime;

    private String  validTime;

    @Override
    public String toString() {
        return "ProductDTO{" +
                "price='" + price + '\'' +
                ", stock='" + stock + '\'' +
                ", saleTime='" + saleTime + '\'' +
                ", validTime='" + validTime + '\'' +
                '}';
    }

    public String getPrice() {
        return price;
    }

    public void setPrice(String price) {
        this.price = price;
    }

    public String getStock() {
        return stock;
    }

    public void setStock(String stock) {
        this.stock = stock;
    }

    public String getSaleTime() {
        return saleTime;
    }

    public void setSaleTime(String saleTime) {
        this.saleTime = saleTime;
    }

    public String getValidTime() {
        return validTime;
    }

    public void setValidTime(String validTime) {
        this.validTime = validTime;
    }
}
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4.2 定义mapper

mapper:

import org.mapstruct.Mapper;
import org.mapstruct.Mapping;
import org.mapstruct.Mappings;
import org.mapstruct.factory.Mappers;

@Mapper
public interface ProductMapper {

    ProductMapper INSTANCE = Mappers.getMapper(ProductMapper.class);

    /**
     * numberFormat 指定基本数据类型与String之间的转换
     * dateFormat 指定Date和String之间的转换
     */
    @Mappings({
            // 这里 # 表示多个数字，  0 表示一个数字（0-9）
            @Mapping(source = "price", target = "price", numberFormat = "#.00元"),
            @Mapping(source = "stock", target = "stock", numberFormat = "#个"),
            @Mapping(target = "saleTime", dateFormat = "yyyy-MM-dd HH:mm:ss"),
            @Mapping(target = "validTime", dateFormat = "yyyy-MM-dd HH:mm")
    })
    ProductDTO toDto(Product product);;
}
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4.3 测试效果

测试demo：

 public static void main(String[] args) {
        Product product = new Product(1,1,new Date(),new Date());
        ProductDTO productDTO = ProductMapper.INSTANCE.toDto(product);
        System.out.println(productDTO.toString());
    }
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结果：

ProductDTO{price='1.00元', stock='1个', saleTime='2022-02-28 17:39:29', validTime='2022-02-28 17:39'}
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5、包含其他类的映射

5.1 相同类

5.1.1 新增实体

user:

public class User {

    private Long userId;

    private String name;

    private String address;

    private Role role;

    public User() {
    }

    public Role getRole() {
        return role;
    }

    public void setRole(Role role) {
        this.role = role;
    }

    public User(Long userId, String name, String address) {
        this.userId = userId;
        this.name = name;
        this.address = address;
    }

    public Long getUserId() {
        return userId;
    }

    public void setUserId(Long userId) {
        this.userId = userId;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }
}


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role:

public class Role {

    private String name;

    private String roleId;

    private String description;

    public Role() {
    }

    public Role(String name, String roleId, String description) {
        this.name = name;
        this.roleId = roleId;
        this.description = description;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getRoleId() {
        return roleId;
    }

    public void setRoleId(String roleId) {
        this.roleId = roleId;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    @Override
    public String toString() {
        return "Role{" +
                "name='" + name + '\'' +
                ", roleId='" + roleId + '\'' +
                ", description='" + description + '\'' +
                '}';
    }
}


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UserRoleDTO:

public class UserRoleDTO {

    private Long id;

    private String name;

    private String address;

    private String roleName;

    private String roleId;

    private String description;

    private Role role;

    public Role getRole() {
        return role;
    }

    public void setRole(Role role) {
        this.role = role;
    }

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getRoleName() {
        return roleName;
    }

    public void setRoleName(String roleName) {
        this.roleName = roleName;
    }

    public String getRoleId() {
        return roleId;
    }

    public void setRoleId(String roleId) {
        this.roleId = roleId;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    @Override
    public String toString() {
        return "UserRoleDTO{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", address='" + address + '\'' +
                ", roleName='" + roleName + '\'' +
                ", roleId='" + roleId + '\'' +
                ", description='" + description + '\'' +
                ", role=" + role +
                '}';
    }
}


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5.1.2 定义mapper

mapper:

import org.mapstruct.Mapper;
import org.mapstruct.Mapping;
import org.mapstruct.factory.Mappers;

@Mapper
public interface UserMapper {

    UserMapper INSTANCE  = Mappers.getMapper(UserMapper.class);


    // role 的属性名一样，类型也一样，不用写Mapping，还有就是 role的赋值是浅拷贝 只拷贝引用，不生成新的对象
    @Mapping(source = "userId", target = "id")// 把user中的userId绑定到目标对象的id属性中
    UserRoleDTO toUserRoleDto(User user);

}

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5.1.3 测试效果

测试demo：

 public static void main(String[] args) {
        User user = new User(1L, "小王八蛋", "北京");
        Role role = new Role("管理员", "2", "描述");
        user.setRole(role);
        UserRoleDTO userRoleDTO = UserMapper.INSTANCE.toUserRoleDto(user);
        System.out.println(userRoleDTO.toString());
    }

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结果：

UserRoleDTO{id=1, name='小王八蛋', address='北京', roleName='null', roleId='null', description='null', role=Role{name='管理员', roleId='2', description='描述'}}

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5.2 不同类

5.2.1 新增实体

user:

public class User {

    private Long userId;

    private String name;

    private String address;

    private Role role;

    public User() {
    }

    public Role getRole() {
        return role;
    }

    public void setRole(Role role) {
        this.role = role;
    }

    public User(Long userId, String name, String address) {
        this.userId = userId;
        this.name = name;
        this.address = address;
    }

    public Long getUserId() {
        return userId;
    }

    public void setUserId(Long userId) {
        this.userId = userId;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }
}


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role:

public class Role {

    private String name;

    private String roleId;

    private String description;

    public Role() {
    }

    public Role(String name, String roleId, String description) {
        this.name = name;
        this.roleId = roleId;
        this.description = description;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getRoleId() {
        return roleId;
    }

    public void setRoleId(String roleId) {
        this.roleId = roleId;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    @Override
    public String toString() {
        return "Role{" +
                "name='" + name + '\'' +
                ", roleId='" + roleId + '\'' +
                ", description='" + description + '\'' +
                '}';
    }
}


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UserRoleDTO:

public class UserRoleDTO {

    private Long id;

    private String name;

    private String address;

    private String roleName;

    private String roleId;

    private String description;

    private RoleDTO role;

    public RoleDTO getRole() {
        return role;
    }

    public void setRole(RoleDTO role) {
        this.role = role;
    }

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getRoleName() {
        return roleName;
    }

    public void setRoleName(String roleName) {
        this.roleName = roleName;
    }

    public String getRoleId() {
        return roleId;
    }

    public void setRoleId(String roleId) {
        this.roleId = roleId;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    @Override
    public String toString() {
        return "UserRoleDTO{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", address='" + address + '\'' +
                ", roleName='" + roleName + '\'' +
                ", roleId='" + roleId + '\'' +
                ", description='" + description + '\'' +
                ", role=" + role +
                '}';
    }
}


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RoleDTO:

public class RoleDTO {

    private String name;

    private String id;

    private String description;


    public RoleDTO(String name, String id, String description) {
        this.name = name;
        this.id = id;
        this.description = description;
    }

    public RoleDTO() {
    }

    @Override
    public String toString() {
        return "RoleDTO{" +
                "name='" + name + '\'' +
                ", id='" + id + '\'' +
                ", description='" + description + '\'' +
                '}';
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }
}


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5.2.2 定义mapper

mapper:

import org.mapstruct.Mapper;
import org.mapstruct.Mapping;
import org.mapstruct.factory.Mappers;

@Mapper
public interface UserMapper {

    UserMapper INSTANCE  = Mappers.getMapper(UserMapper.class);

    // 这两个方法写在一起也行，分别写在两个接口里也行，执行时，都会自动调用
    @Mapping(source = "userId", target = "id") // 把user中的userId绑定到目标对象的id属性中
    UserRoleDTO toUserRoleDto(User user);

    // 当上面那个toUserRoleDto方法调用时，会自动调用这个方法来完成 User类中的Role 到 UserRoleDTO类中的RoleDTO  的转换
    @Mapping(source = "roleId", target = "id")
    RoleDTO toRoleDto(Role role);


}

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5.2.3 测试效果

测试demo：

 public static void main(String[] args) {
        Product product = new Product(1,1,new Date(),new Date());
        ProductDTO productDTO = ProductMapper.INSTANCE.toDto(product);
        System.out.println(productDTO.toString());
    }

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结果：

UserRoleDTO{id=1, name='小王八蛋', address='北京', roleName='null', roleId='null', description='null', role=RoleDTO{name='管理员', id='2', description='描述'}}

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6、自定义映射方式

6.1 新增实体

product:

import java.util.Date;

public class Product {

    private int price;

    private int stock;

    private Date saleTime;

    private Date validTime;

    private Boolean isDone;

    public Product() {
    }

    public Product(int price, int stock, Date saleTime, Date validTime, Boolean isDone) {
        this.price = price;
        this.stock = stock;
        this.saleTime = saleTime;
        this.validTime = validTime;
        this.isDone = isDone;
    }

    public Boolean getIsDone() {
        return isDone;
    }

    public void setIsDone(Boolean done) {
        isDone = done;
    }

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    public int getStock() {
        return stock;
    }

    public void setStock(int stock) {
        this.stock = stock;
    }

    public Date getSaleTime() {
        return saleTime;
    }

    public void setSaleTime(Date saleTime) {
        this.saleTime = saleTime;
    }

    public Date getValidTime() {
        return validTime;
    }

    public void setValidTime(Date validTime) {
        this.validTime = validTime;
    }
}


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productDTO:

public class ProductDTO {

    private String price;

    private String stock;

    private String saleTime;

    private String validTime;

    private String isDone;

    @Override
    public String toString() {
        return "ProductDTO{" +
                "price='" + price + '\'' +
                ", stock='" + stock + '\'' +
                ", saleTime='" + saleTime + '\'' +
                ", validTime='" + validTime + '\'' +
                ", isDone='" + isDone + '\'' +
                '}';
    }

    public String getIsDone() {
        return isDone;
    }

    public void setIsDone(String isDone) {
        this.isDone = isDone;
    }

    public String getPrice() {
        return price;
    }

    public void setPrice(String price) {
        this.price = price;
    }

    public String getStock() {
        return stock;
    }

    public void setStock(String stock) {
        this.stock = stock;
    }

    public String getSaleTime() {
        return saleTime;
    }

    public void setSaleTime(String saleTime) {
        this.saleTime = saleTime;
    }

    public String getValidTime() {
        return validTime;
    }

    public void setValidTime(String validTime) {
        this.validTime = validTime;
    }
}

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6.2 自定义映射

自定义：

import org.mapstruct.Named;

@Named("DoneFormater")
public class DoneFormater {

    @Named("DoneFormater")
    public String toStr(Boolean isDone) {
        if (isDone) {
            return "已完成";
        } else {
            return "未完成";
        }
    }

    @Named("DoneDetailFormater")
    public String toDetail(Boolean isDone) {
        if (isDone) {
            return "该产品已完成";
        } else {
            return "该产品未完成";
        }
    }

    public Boolean toBoolean(String str) {
        if (str.equals("已完成")) {
            return true;
        } else {
            return false;
        }
    }

}

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6.3 定义mapper

mapper:

import org.mapstruct.Mapper;
import org.mapstruct.Mapping;
import org.mapstruct.Mappings;
import org.mapstruct.factory.Mappers;

// 通过uses 来导入上面我们写的 自定义映射方法
@Mapper( uses = {DoneFormater.class})
public interface ProductMapper {

    ProductMapper INSTANCE = Mappers.getMapper(ProductMapper.class);

    /**
     * numberFormat 指定基本数据类型与String之间的转换
     * dateFormat 指定Date和String之间的转换
     */
    @Mappings({
            // 这里 # 表示多个数字，  0 表示一个数字（0-9）
            @Mapping(source = "price", target = "price", numberFormat = "#.00元"),
            @Mapping(source = "stock", target = "stock", numberFormat = "#个"),
            @Mapping(target = "saleTime", dateFormat = "yyyy-MM-dd HH:mm:ss"),
            @Mapping(target = "validTime", dateFormat = "yyyy-MM-dd HH:mm"),
            // 当有多个方法 拥有一样的参数和返回类型时，需要指定使用其中的哪一个，使用qualifiedByName指定
            @Mapping(source = "isDone", target = "isDone", qualifiedByName = "DoneDetailFormater")
    })
    ProductDTO toDto(Product product);;
}

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6.4 测试效果

测试demo:

public static void main(String[] args) {
        Product product = new Product(1,1,new Date(),new Date(),true);
        ProductDTO productDTO = ProductMapper.INSTANCE.toDto(product);
        System.out.println(productDTO.toString());
    }

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效果：

ProductDTO{price='1.00元', stock='1个', saleTime='2022-02-28 22:18:25', validTime='2022-02-28 22:18', isDone='该产品已完成'}

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7、 List映射

7.1 新增实体

product:

import java.util.Date;

public class Product {

    private int price;

    private int stock;

    private Date saleTime;

    private Date validTime;

    private Boolean isDone;

    public Product() {
    }

    public Product(int price, int stock, Date saleTime, Date validTime, Boolean isDone) {
        this.price = price;
        this.stock = stock;
        this.saleTime = saleTime;
        this.validTime = validTime;
        this.isDone = isDone;
    }

    public Boolean getIsDone() {
        return isDone;
    }

    public void setIsDone(Boolean done) {
        isDone = done;
    }

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    public int getStock() {
        return stock;
    }

    public void setStock(int stock) {
        this.stock = stock;
    }

    public Date getSaleTime() {
        return saleTime;
    }

    public void setSaleTime(Date saleTime) {
        this.saleTime = saleTime;
    }

    public Date getValidTime() {
        return validTime;
    }

    public void setValidTime(Date validTime) {
        this.validTime = validTime;
    }
}


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productDTO:

public class ProductDTO {

    private String price;

    private String stock;

    private String saleTime;

    private String validTime;

    private String isDone;

    @Override
    public String toString() {
        return "ProductDTO{" +
                "price='" + price + '\'' +
                ", stock='" + stock + '\'' +
                ", saleTime='" + saleTime + '\'' +
                ", validTime='" + validTime + '\'' +
                ", isDone='" + isDone + '\'' +
                '}';
    }

    public String getIsDone() {
        return isDone;
    }

    public void setIsDone(String isDone) {
        this.isDone = isDone;
    }

    public String getPrice() {
        return price;
    }

    public void setPrice(String price) {
        this.price = price;
    }

    public String getStock() {
        return stock;
    }

    public void setStock(String stock) {
        this.stock = stock;
    }

    public String getSaleTime() {
        return saleTime;
    }

    public void setSaleTime(String saleTime) {
        this.saleTime = saleTime;
    }

    public String getValidTime() {
        return validTime;
    }

    public void setValidTime(String validTime) {
        this.validTime = validTime;
    }
}

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7.2 定义mapper

mapper:

import org.mapstruct.Mapper;
import org.mapstruct.Mapping;
import org.mapstruct.Mappings;
import org.mapstruct.factory.Mappers;

import java.util.List;

// 通过uses 来导入上面我们写的 自定义映射方法
@Mapper( uses = {DoneFormater.class})
public interface ProductMapper {

    ProductMapper INSTANCE = Mappers.getMapper(ProductMapper.class);

    /**
     * numberFormat 指定基本数据类型与String之间的转换
     * dateFormat 指定Date和String之间的转换
     */
    @Mappings({
            // 这里 # 表示多个数字，  0 表示一个数字（0-9）
            @Mapping(source = "price", target = "price", numberFormat = "#.00元"),
            @Mapping(source = "stock", target = "stock", numberFormat = "#个"),
            @Mapping(target = "saleTime", dateFormat = "yyyy-MM-dd HH:mm:ss"),
            @Mapping(target = "validTime", dateFormat = "yyyy-MM-dd HH:mm"),
            // 当有多个方法 拥有一样的参数和返回类型时，需要指定使用其中的哪一个，使用qualifiedByName指定
            @Mapping(source = "isDone", target = "isDone", qualifiedByName = "DoneDetailFormater")
    })
    ProductDTO toDto(Product product);

    // 	当执行 下面这个List的转换时，会遍历list: product，
    //  然后自动调用上面的Product转ProductDTO的转换方法，来进行转换
    List<ProductDTO> toList(List<Product> productList);
}

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7.3 测试效果

测试demo:

public static void main(String[] args) {
        Product product = new Product(1,1,new Date(),new Date(),true);
        List<Product> list = new ArrayList<>();
        list.add(product);
        List<ProductDTO> productDTOS = ProductMapper.INSTANCE.toList(list);
        productDTOS.stream().forEach(productDTO -> System.out.println(productDTO.toString()));
    }

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结果：

ProductDTO{price='1.00元', stock='1个', saleTime='2022-02-28 22:29:42', validTime='2022-02-28 22:29', isDone='该产品已完成'}

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8、Map映射

8.1 定义mapper

import org.mapstruct.MapMapping;
import org.mapstruct.Mapper;
import org.mapstruct.factory.Mappers;

import java.util.Date;
import java.util.Map;

@Mapper
public interface MapMapper {

    MapMapper INSTANCE = Mappers.getMapper(MapMapper.class);

    @MapMapping(valueDateFormat = "yyyy-MM-dd HH:mm:ss")
    Map<String, String> toDTO(Map<Long, Date> map);

}

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8.2 测试效果

测试demo:

public static void main(String[] args) {
        Map<Long,Date> param = new HashMap<>();
        param.put(1L,new Date());
        Map<String, String> stringStringMap = MapMapper.INSTANCE.toDTO(param);
        for (Map.Entry<String, String> stringStringEntry : stringStringMap.entrySet()) {
            System.out.println(stringStringEntry.getKey());
            System.out.println(stringStringEntry.getValue());
        }
    }

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结果：

1
2022-02-28 22:39:07

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9、枚举映射

9.1 新增枚举

9.2 定义mapper

9.3 测试效果

10、使用表达式和默认值

10.1 定义mapper

// 通过uses 来导入上面我们写的 自定义映射方法
@Mapper( uses = {DoneFormater.class})
public interface ProductMapper {

    ProductMapper INSTANCE = Mappers.getMapper(ProductMapper.class);



        //expression中可以直接写Java代码
        @Mappings({
        // 设置默认值
        @Mapping(target = "productId", source = "productId", defaultValue = "123"), //当product的productId为null，设置为0
        // 表达式
        @Mapping(target = "price", expression = "java(product.getPrice1() + product.getPrice2())"),//直接相加
        @Mapping(target = "price2", expression = "java(MathUtils.addAndReturn0(product.getPrice1(), product.getPrice2()))"),//使用工具类处理
        // 常量
        @Mapping(target = "stock", constant = "100"), //固定设置为100, 常量
        })
        ProductDTO toDTO(Product product);
}

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11、典型例子：

@Data
@AllArgsConstructor
@NoArgsConstructor
public class RespLoginDTO {

    private String id;
    private String username;
    private String cname;
    private String sex;
    private String mobile;
    private String email;
    private String token;
    private String description;
    private String roleName;
    private String roleId;
    private List menus;

    @Data
    @AllArgsConstructor
    @NoArgsConstructor
    public static class MenusBean {
       
        private int id;
        private String title;
        private String icon;
        private List children;


        @Data
        @AllArgsConstructor
        @NoArgsConstructor
        public static class ChildrenBean {
      
            private int id;
            private String title;
            private String path;


        }
    }
}



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@Mapper(componentModel = "spring")
public interface RespLoginDtoConverter {

    RespLoginDtoConverter INSTANCE = Mappers.getMapper(RespLoginDtoConverter.class);

    @Mappings({
            @Mapping(source = "user.userId", target = "id"),
            @Mapping(source = "userPerms", target = "menus")
    })
    RespLoginDTO createRespLoginDTO(User user, Role role, List userPerms, String token);


    // 下面的几个方法都是为了辅组完成上面的那个createRespLoginDTO转换而写的
    List createMenusBeans(List userPerms);

    @Mappings({
            @Mapping(source = "mainPerm.permId", target = "id"),
            @Mapping(source = "mainPerm.permTitle", target = "title"),
            @Mapping(source = "mainPerm.permIcon", target = "icon"),
            @Mapping(source = "childrenPrem", target = "children")
            //@Mapping(source = "userPerms.mainPerm", target = "menus"),
    })
    RespLoginDTO.MenusBean createMenusBean(UserPerm userPerm);

    List createMenusBeanChildrenBeans(List perms);

    @Mappings({
            @Mapping(source = "permId", target = "id"),
            @Mapping(source = "permTitle", target = "title"),
            @Mapping(source = "permPath", target = "path")
            //@Mapping(source = "userPerms.mainPerm", target = "menus"),
    })
    RespLoginDTO.MenusBean.ChildrenBean createChildrenBean(Perm perm);

}


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@Data
@AllArgsConstructor
@NoArgsConstructor
public class UserPerm {
    /**
     * 主权限
     */
    private Perm mainPerm;
    /**
     * 子权限
     */
    private List childrenPrem;
}
@Data
@EqualsAndHashCode(callSuper = false)
public class Perm implements Serializable {
    private static final long serialVersionUID = 1L;
    private Long permId;
    private Long parentId;
    private String permCode;
    private String permName;
    private LocalDateTime createDate;
    private String permPath;
    private String permTitle;
    private String permIcon;
    private Boolean permType;
}


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参考：https://www.cnblogs.com/vb-ahh/p/14836453.html

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原文地址：https://blog.csdn.net/weixin_43675226/article/details/126872799

MapStruct入门及集成springboot

MapStruct入门及集成springboot

1、引入依赖

2、简单示例

2.1 新增实体

2.2 定义mapper

2.3 测试效果

3、多个入参构造一个对象

3.1 新增实体

3.2 定义mapper

3.3 测试效果

4、数据类型转换 （int -> string 等）

4.1 新增实体

4.2 定义mapper

4.3 测试效果

5、包含其他类的映射

5.1 相同类

5.1.1 新增实体

5.1.2 定义mapper

5.1.3 测试效果

5.2 不同类

5.2.1 新增实体

5.2.2 定义mapper

5.2.3 测试效果

6、自定义映射方式

6.1 新增实体

6.2 自定义映射

6.3 定义mapper

6.4 测试效果

7、 List映射

7.1 新增实体

7.2 定义mapper

7.3 测试效果

8、Map映射

8.1 定义mapper

8.2 测试效果

9、枚举映射

9.1 新增枚举

9.2 定义mapper

9.3 测试效果

10、使用表达式和默认值

10.1 定义mapper

11、典型例子：

4、数据类型转换（int -> string 等）