Question

我正在使用Picasso将图像加载到应用程序中。我从服务获取图像的空值。如何处理空值。

我的代码：

if(reviewdata.get(position).user.getPhotoUrl().isEmpty() || reviewdata.get(position).user.getPhotoUrl() == null){
               Picasso.with(getApplicationContext()).load(R.drawable.profile)
                       .into(viewHolder.user_image);
            }else if(reviewdata.get(position).user.getPhotoUrl() != null){
            Picasso.with(getApplicationContext()).load(reviewdata.get(position).user.getPhotoUrl()).placeholder(R.drawable.profile)
                    .into(viewHolder.user_image);}

错误：

10-04 08:42:43.653 23300-23300/ E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.restosapp.restoss, PID: 23300
    java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.isEmpty()' on a null object reference
        at .listing.DetailpageActivtiy$Reviewpageadapter.onBindViewHolder(DetailpageActivtiy.java:1198)
        at cooss.listing.DetailpageActivtiy$Reviewpageadapter.onBindViewHolder(DetailpageActivtiy.java:1172)
        at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:6673)

Answer 1

第一个优先级如果条件为真，则执行以下操作：

if(reviewdata.get(position).user.getPhotoUrl()!=null && !reviewdata.get(position).user.getPhotoUrl().isEmpty())
{

  Picasso.with(getApplicationContext()).load(reviewdata.get(position).user.getPhotoUrl()).placeholder(R.drawable.profile)
                .into(viewHolder.user_image);}
}
else 
{
 Picasso.with(getApplicationContext()).load(R.drawable.profile)
                   .into(viewHolder.user_image);
}

它将解决您的问题

Answer 2

在if

中更改条件顺序

if(reviewdata.get(position).user.getPhotoUrl() == null || reviewdata.get(position).user.getPhotoUrl().isEmpty() )

Answer 3

尝试一下：

 public boolean isEmpty(String s) {
               return s.trim().equals("") || s == null || s.isEmpty() || s.equals("null");
       }

if(!isEmpty(reviewdata.get(position).user.getPhotoUrl())){
 Picasso.with(getApplicationContext()).load(reviewdata.get(position).user.getPhotoUrl()).placeholder(R.drawable.profile)
                    .into(viewHolder.user_image);
}
else{
 Picasso.with(getApplicationContext()).load(R.drawable.profile)
                       .into(viewHolder.user_image);
}

Answer 4

无需使用Picasso检查空值。毕加索足够聪明，它将处理空值。

Picasso.with(getApplicationContext()).load(reviewdata.get(position).user.getPhotoUrl()).placeholder(R.drawable.profile).into(viewHolder.user_image);}

如果URL为空或为空，它将显示placeholder图片。

如何在改造中检查空值

4 个答案: