Java 反射 : Invoking Setter and Getter method for collection type Object

Question

我有两个不同的用户定义对象包.....

1) ws.lender.dto (all Objects exists in this package are source side).
2) copl.com.dto (all Objects exists in this package are destination side).

两侧的对象层次结构和对象名称不同。我想 按字段将源端对象复制到目标端对象字段或 通过使用反射的 getter 和 setter。

例如

源端对象

   package ws.lender.dto;

    @XmlAccessorType(XmlAccessType.FIELD)
    @XmlType(name = "CustomerAddresses", propOrder = {
        "previousAddresses"
    })
    public class CustomerAddresses {

        protected PreviousAddresses previousAddresses;

        public PreviousAddresses getPreviousAddresses() {
            return previousAddresses;
        }

        public void setPreviousAddresses(PreviousAddresses value) {
            this.previousAddresses = value;
        }

    }


@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "PreviousAddresses", propOrder = {
    "previousAddress"
})
public class PreviousAddresses {

    @XmlElement(name = "PreviousAddress", required = true)
    protected List<PreviousAddress> previousAddress;

    public List<PreviousAddress> getPreviousAddress() {
        if (previousAddress == null) {
            previousAddress = new ArrayList<PreviousAddress>();
        }
        return this.previousAddress;
    }
}


@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "PreviousAddress", propOrder = {

    "streetNo",
    "streetName"
})
public class PreviousAddress {

    @XmlElement(name = "StreetNo", required = true)
    protected String streetNo;
    @XmlElement(name = "StreetName", required = true)
    protected String streetName;

    public String getStreetNo() {
        return streetNo;
    }
    public void setStreetNo(String value) {
        this.streetNo = value;
    }
    public String getStreetName() {
        return streetName;
    }
    public void setStreetName(String value) {
        this.streetName = value;
    }
}

目标端对象

package copl.com.dto;

@javax.persistence.Entity
public class Customer implements java.io.Serializable
{
private Set<CustomerAddress> customerAddresses;

   public Set<CustomerAddress> getCustomerAddresses()
    {
        return customerAddresses;
    }

        public void setCustomerAddresses(Set<CustomerAddress> customerAddresses)
    {
        this.customerAddresses = customerAddresses;
    }
}

@javax.persistence.Entity
public class CustomerAddress implements java.io.Serializable
{   
    private String unitNumber;
    private String streetName;
    private String streetNumber;

   public String getUnitNumber()
    {
        return unitNumber;
    }   
        public void setUnitNumber(String unitNumber)
    {
        this.unitNumber = unitNumber;
    }
        public String getStreetName()
    {
        return streetName;
    }
       public String getStreetNumber()
    {
        return streetNumber;
    }
        public void setStreetName(String streetName)
    {
        this.streetName = streetName;
    }

    public void setStreetNumber(String streetNumber)
    {
        this.streetNumber = streetNumber;
    }
}   

Answer 1

我想你可以使用 MapStruct到具有不同属性名称的 POJO 之间的映射。

但是你的场景很复杂，因为你要转换ws.lender.dto.CustomerAddresses至 copl.com.dto.Customer ，这意味着转换 List<ws.lender.dto.PreviousAddress>包含在 ws.lender.dto.PreviousAddresses 中对象，到 Set<copl.com.dto.CustomerAddress>包含在 copl.com.dto.Customer 中对象。

所以，我会一步一步解释。

1。从 ws.lender.dto.PreviousAddress 转换至 copl.com.dto.CustomerAddress

要进行此转换，您需要一个接口(interface)(MapStruct 将为此创建一个实例)负责从源对象映射到目标对象:

import ws.lender.dto.PreviousAddress;
import copl.com.dto.CustomerAddress;

@Mapper
public interface CustomerAddressesMapper{

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

    @Mappings(@Mapping(source = "streetNo", target = "streetNumber")
    CustomerAddress previousToCustomerObject(PreviousAddress address);
}

这个接口(interface)会映射一个PreviousAddress反对 CustomerAddress考虑到streetNo属性必须映射到 streetNumber . unitNumber 没有映射属性原因没有它的来源。

2。转换 List<ws.lender.dto.PreviousAddress>至 Set<copl.com.dto.CustomerAddress>

现在您必须向现有的 CustomerAddressesMapper 添加另一种映射方法接口(interface):

Set<CustomerAddress> previousToCustomerSet(List<PreviousAddress> addresses);

此方法将使用前者 previousToCustomerObject将源列表的每个元素转换为目标集。

3。从 ws.lender.dto.CustomerAddresses 转换至 copl.com.dto.Customer

最后需要将最后一个映射方法添加到CustomerAddressesMapper接口(interface):

@Mappings(@Mapping(source = "previousAddresses.previousAddress", target = "customerAddresses")
Customer customerAddrsToCustomerObject(CustomerAddresses addresses);

这是您映射原始对象的地方，转换 previousAddresses.previousAddress属性为 customerAddresses属性，使用以前的方法。

4。使用映射器

要使用映射器，您必须编写如下代码:

CustomerAddressesMapper mapper = CustomerAddressesMapper.INSTANCE;
CustomerAddresses origin = //Retrieve it from anywhere
Customer dest = mapper.customerAddrsToCustomerObject(origin);

5。设置

MapStruct 是一个源代码生成器，因此您需要正确配置您的 pom.xml包括 MapStruct 依赖项并调用此代码生成。你可以看到如何做到这一点 here

好吧，我不会构建和运行这段代码，但这是实现它的方式。

希望对您有所帮助!