What is the best trick to handle null values in Recycler-view onBindViewHolder?

I handled many exception regarding null/index-outof-bound etc. But i am thinking that this is not right way to go like if/else , so anyone can guide me How to handle all null condition in onBindViewHolder?

@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position)
{
if (holder instanceof CustDtlsHolder)
{

// >i am getting here lots of null values below


if(position < arr_custdetails.size())
{
String dateInString = arr_custdetails.get(position).getLastVisitDate();
Date date = null;
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
try {
date = formatter.parse(dateInString);
SimpleDateFormat formatter2 = new SimpleDateFormat("dd/MMM/yyyy");
update_date = formatter2.format(date);
update_date = update_date.replace("/"," ");
} catch (ParseException e) {
e.printStackTrace();
} catch (NullPointerException e){
update_date="null";
}

//> same getting null values below as mention above.

((CustDtlsHolder) holder).txt_mbr_date.setText(update_date.substring(0,2));
((CustDtlsHolder) holder).txt_mbr_year.setText(update_date.substring(3,6)+ " "+update_date.substring(7,11));
((CustDtlsHolder) holder).txt_mbr_name.setText(arr_custdetails.get(position).getFullName());
((CustDtlsHolder) holder).txt_mbr_email.setText(arr_custdetails.get(position).getEmailAddress());
((CustDtlsHolder) holder).txt_mbr_phone.setText(arr_custdetails.get(position).getMobileNumber());
((CustDtlsHolder) holder).txt_mbr_avgSize_val.setText(""+Math.round(arr_custdetails.get(position).getAvgBasketVal())+" , "+Math.round(arr_custdetails.get(position).getAvgBasketQty())+" "+"Units");
if(arr_custdetails.get(position).getLast90dayVisit() == null || arr_custdetails.get(position).getLast90dayVisit().equals(""))
{
((CustDtlsHolder) holder).txt_mbr_avgVisits_val.setText("");
}
else
{
((CustDtlsHolder) holder).txt_mbr_avgVisits_val.setText(arr_custdetails.get(position).getLast90dayVisit()+ " in Last 90 days");
}
((CustDtlsHolder) holder).txt_mbr_noofvisit.setText(arr_custdetails.get(position).getMbrVisitCount());

}
}


4 Answers
4

you can use this way also it will be helpful for you...please try this.

model:

public class YourModelName{

private String mobileNumber="";
private String fullName="";
private String emailAddress="";
private String avgBasketVal="";
private String avgBasketQty="";
private String last90dayVisit="";

public String getMobileNumber() {
return mobileNumber;
}

public void setMobileNumber(String mobileNumber) {
this.mobileNumber = mobileNumber;
}

public String getFullName() {
return fullName;
}

public void setFullName(String fullName) {
this.fullName = fullName;
}

public String getEmailAddress() {
return emailAddress;
}

public void setEmailAddress(String emailAddress) {
this.emailAddress = emailAddress;
}

public String getAvgBasketVal() {
return avgBasketVal;
}

public void setAvgBasketVal(String avgBasketVal) {
this.avgBasketVal = avgBasketVal;
}

public String getAvgBasketQty() {
return avgBasketQty;
}

public void setAvgBasketQty(String avgBasketQty) {
this.avgBasketQty = avgBasketQty;
}

public String getLast90dayVisit() {
return last90dayVisit;
}

public void setLast90dayVisit(String last90dayVisit) {
this.last90dayVisit = last90dayVisit;
}

}


Edit @dilip answer:

public class YourModelName{

private String mobileNumber="";
private String fullName="";
private String emailAddress="";
private String avgBasketVal="";
private String avgBasketQty="";
private String last90dayVisit="";

public String getMobileNumber() {
return mobileNumber;
}

public void setMobileNumber(String mobileNumber) {
if(mobileNumber != null)
this.mobileNumber = mobileNumber;
}

public String getFullName() {
return fullName;
}

public void setFullName(String fullName) {
if(fullName != null)
this.fullName = fullName;
}

public String getEmailAddress() {
return emailAddress;
}

public void setEmailAddress(String emailAddress) {
if(emailAddress != null)
this.emailAddress = emailAddress;
}

public String getAvgBasketVal() {
return avgBasketVal;
}

public void setAvgBasketVal(String avgBasketVal) {
if(avgBasketVal != null)
this.avgBasketVal = avgBasketVal;
}

public String getAvgBasketQty() {
return avgBasketQty;
}

public void setAvgBasketQty(String avgBasketQty) {
if(avgBasketQty != null)
this.avgBasketQty = avgBasketQty;
}

public String getLast90dayVisit() {
return last90dayVisit;
}

public void setLast90dayVisit(String last90dayVisit) {
if(last90dayVisit != null)
this.last90dayVisit = last90dayVisit;
}

}


If your string value is null then return "".

Hope this may help you.

For string values you can use android's TextUtils, and fyi you can even set null in textView.setText() method:

CustDtlsHolder custDtlsHolder = ((CustDtlsHolder) holder);
String value = arr_custdetails.get(position).getLast90dayVisit();
if (!TextUtils.isEmpty(value) {
value += " in Last 90 days";
}
custDtlsHolder.txt_mbr_avgVisits_val.setText(value);


But as has been written, you should better create bind method for clearer code. Usually in Java projects I use ButterKnife and create some base classes like that.

BaseRecyclerAdapter:

public abstract class BaseRecyclerAdapter<T> extends RecyclerView.Adapter<BaseViewHolder> {

private List<T> items;
private OnRecyclerItemClickListener<T> onRecyclerItemClickListener;

public BaseRecyclerAdapter(List<T> items) {
this.items = items;
}

@Override public void onBindViewHolder(BaseViewHolder holder, int position) {
T item = getItem(position);
holder.bind(item);
holder.itemView.setOnClickListener(v -> {
if (onRecyclerItemClickListener != null) {
onRecyclerItemClickListener.onItemClick(this, item);
}
});
}

protected final View getViewHolderView(ViewGroup parent, @LayoutRes int itemLayoutId) {
return LayoutInflater.from(parent.getContext()).inflate(itemLayoutId, parent, false);
}
// ... other base methods such as getItemCount(), setItems, etc.


BaseViewHolder:

public abstract class BaseViewHolder<T> extends RecyclerView.ViewHolder {

protected abstract void bind(T item);

public BaseViewHolder(View itemView) {
super(itemView);
ButterKnife.bind(this, itemView);
}

public final Context getContext() {
return itemView.getContext();
}


And usage:

final class MyAdapter extends BaseRecyclerAdapter<MyItem> {
MyAdapter(List<MyItem> items) { super(items); }

@Override public BaseViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
return new MyViewHolder(getViewHolderView(parent, R.layout.item));
}

class MyViewHolder extends BaseViewHolder<MyItem> {
@BindView(R.id.txt_date) TextView txtDate;

MyViewHolder(View itemView) { super(itemView); }

@Override protected void bind(MyItem item) {
txtDate.setText(getContext().getString(R.string.item_created, DateTimeUtils.formatDate(item.date)));
// put your null checking here
}
}


Above answer which modifies the Model class didn't work for me.

This is what I came up with

@Override
public void onBindViewHolder(HomeViewHolder holder, int position)
{


String title;

try {

title = myList.get(position).getTitle();

} catch (NullPointerException e) {

title = "Null";

}

holder.tvTitle.setText(title);

}


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