在Android中使用ModelMapper库来映射属性时,如果遇到需要在原始对象的一个子属性上映射属性的情况,可以通过以下步骤解决:
implementation 'org.modelmapper:modelmapper:2.4.4'
public class User {
private String name;
private Address address;
// getters and setters
}
public class Address {
private String city;
private String country;
// getters and setters
}
public class UserDto {
private String fullName;
private String city;
private String country;
// getters and setters
}
import org.modelmapper.ModelMapper;
import org.modelmapper.PropertyMap;
public class UserMapper {
private ModelMapper modelMapper;
public UserMapper() {
modelMapper = new ModelMapper();
modelMapper.addMappings(new PropertyMap() {
protected void configure() {
map().setFullName(source.getName());
map().setCity(source.getAddress().getCity());
map().setCountry(source.getAddress().getCountry());
}
});
}
public UserDto mapUserToDto(User user) {
return modelMapper.map(user, UserDto.class);
}
}
在上述代码中,我们创建了一个UserMapper类,并在构造函数中配置了映射规则。我们使用PropertyMap来指定如何将User对象映射到UserDto对象。在configure()方法中,我们使用map()方法将User对象的属性映射到UserDto对象的属性。
User user = new User();
user.setName("John Doe");
Address address = new Address();
address.setCity("New York");
address.setCountry("USA");
user.setAddress(address);
UserMapper userMapper = new UserMapper();
UserDto userDto = userMapper.mapUserToDto(user);
通过以上步骤,就可以在Android中使用ModelMapper库来在原始对象的一个子属性上映射属性。在这个示例中,我们将User对象的name属性映射到UserDto对象的fullName属性,并将User对象的address属性中的city和country属性分别映射到UserDto对象的city和country属性。