采用不同 class 对象的通用方法

Question

I have 3 class(techspecs, packages, and features) objects where they all share the same fields. The fields are big and instead of repeating setting the fields of each field 3 times(which ends up looking like duplicates), I would like to pass the class objects into one method that uses the generic object to setting the object fields.

I tried passing the class object as a generic but then i dont have access to its members. This is what i tried

  Packages packagesFeatures = new Packages();
  TechSpecs techSpecsFeature = new TechSpecs();
  packagesFeatures  =  addFeatures(Packages.class, packagesFeatures, vehFeatures);
  techSpecsFeature  = addFeatures(TechSpecs.class, techSpecsFeature, vehFeatures);

Then

    private <T> T addFeatures(Class<T> clazz, T obj,  VehicleFeature vehFeatures) {

    T inst = null;

    try {
        inst = clazz.getDeclaredConstructor().newInstance();

    } catch (InstantiationException | IllegalAccessException | InvocationTargetException | NoSuchMethodException e) {
        e.printStackTrace();
    }
    if (inst instanceof Packages) {
      obj = (T) new Packages();


    }
    if(inst instanceof TechSpecs){
        obj = (T) new TechSpecs();
    }

    if(inst instanceof Features){
        obj = (T) new Features();
    }


    //then somthing like:
    //obj.setFeatureId(vehFeatures.getFeatureId());
    // obj.setFeatureKey(vehFeatures.getFeatureKey());
    // obj.setFeatureCode(vehFeatures.getFeatureCode());

    return obj;

EDIT Each of the 3 classes extend BaseFeatures

public abstract class BaseFeatures {
private String featureId;
private String featureKey;
private String featureCode;
private String subSectionId;
private String subSectionName;
private String featureIdName;
private Integer subSectionRank;
private Integer featureImgClassificationId;
private String featureImgClassification;
private boolean has3DAnimation;
private String sectionId;
private String searchKeys;
private String description;
private String featureName;
private double featureRank;
private String geoId;
private String ecc;
private String specSegments;
private String featureIconType;
private String featureIconText;
private double featureValue;
private boolean standardCertain;
private boolean built;
private List<String> featureKeyAnswers;
private boolean isNumeric;
private boolean adasFeature;
private List<String> icCodeAnswers;
private String featureKeyNoBrand;
private List<StyleInfo> styles;
private List<String> optionCodes;
private List<String> changeOptions;

//getters and setters.

Here is one of the classes.

public class TechSpecs extends BaseFeatures {

private String techSpecs;


public void setTechSpecs(String techSpecs) {
    this.techSpecs = techSpecs;
}

public String getTechSpecs(){
    return techSpecs;
}

}

All of these fields need to be set in the class object of all 3 classes

EDIT 2

VehicleFeature Class is a standalone class

@JsonInclude(JsonInclude.Include.NON_NULL)
public class VehicleFeature {
private String section;
private String subSection;
private String featureName;
private String subSectionId;
private String sectionName;
private String subSectionName;

Answer 1

If it were me, I would simplify your addFeatures(...) method to something like:

private <T> T addFeatures(Class<T> clazz, BaseFeatures theseFeatures) {

    T obj = null;
    
    try {
        
        obj = clazz.getDeclaredConstructor(BaseFeatures.class).newInstance(theseFeatures);              
        
    } catch (ReflectiveOperationException roe) {
        
        roe.printStackTrace();
    }
    
    return obj;
}

I'd add these two constructors to BaseFeatures :

public abstract class BaseFeatures{

    protected String featureId;
    
    protected String featureKey;
    
    protected String featureCode;

    /*...*/
    
    protected BaseFeatures(String featureId, String featureKey, String featureCode){
        this.featureId = featureId;
        this.featureKey = featureKey;
        this.featureCode = featureCode;
    }
    
    protected BaseFeatures(BaseFeatures features){
        this.featureId = features.featureId ;
        this.featureKey = features.featureKey;
        this.featureCode = features.featureCode;
    }

    /*...*/
}

You can see how that implementation would actually work , here:

public class BigAssFields {

    /* ... */

    static public void main(String ... args){

        BigAssFields bLike = new BigAssFields();
        
        VehicleFeature vehFeatures = new VehicleFeature("what", "the actual", "Feature");
    
        TechSpecs bigTechSpecs =  bLike.addFeatures(TechSpecs.class, vehFeatures);
    
    }

    /* ... */
}