当我运行应用程序时,它成功启动但在一段时间后它崩溃并显示此错误:
E / AndroidRuntime:FATAL EXCEPTION:main进程:com.tregix.serviceprovider,PID:16455 java.lang.NullPointerException:尝试在java上的空对象引用上调用虚方法'int java.lang.String.length()'。 io.StringReader。(StringReader.java:50)位于android.text.Html.fromHtml上的android.text.HtmlToSpannedConverter.convert(Html.java:758)android.text.Html.fromHtml(Html.java:245) Html.java:188)com.tregix.serviceprovider.adapters.CategoryRecyclerViewAdapter.onBindViewHolder(CategoryRecyclerViewAdapter.java:44)at com.tregix.serviceprovider.adapters.CategoryRecyclerViewAdapter.onBindViewHolder(CategoryRecyclerViewAdapter.java:24)at android.support.v7 .widget.RecyclerView $ Adapter.onBindViewHolder(RecyclerView.java:6673)在android.support.v7.widget.RecyclerView $ Adapter.bindViewHolder(RecyclerView.java:6714)在android.support.v7.widget.RecyclerView $ Recycler.tryBindViewHolderByDeadline (RecyclerView.java:5647)在android.support.v7.widget.RecyclerView $ Recycler.tryGetViewHol android.support.v7.widget.RecyclerView $ Recycler.getViewForPosition(RecyclerView.java:5752)在android.support.v7.widget.RecyclerView $ Recycler.getViewForPosition(RecyclerView.java:5748)的derForPositionByDeadline(RecyclerView.java:5913)
我的代码如下
public class CategoryRecyclerViewAdapter extends RecyclerView.Adapter<CategoryRecyclerViewAdapter.ViewHolder> {
private final List<Category> mValues;
private final OnListInteractionListener mListener;
public CategoryRecyclerViewAdapter(List<Category> items,
OnListInteractionListener listener) {
mValues = items;
mListener = listener;
}
@Override
public CategoryRecyclerViewAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.category_item, parent, false);
return new CategoryRecyclerViewAdapter.ViewHolder(view);
}
@Override
public void onBindViewHolder(final CategoryRecyclerViewAdapter.ViewHolder holder, int position) {
holder.mItem = mValues.get(position);
holder.mCategoryView.setText(Html.fromHtml(mValues.get(position).getTitle()));
if(mValues.get(position).getSubCategories() != null &&
!mValues.get(position).getSubCategories().isEmpty() ) {
String subTitle = Constants.EMPTY_STRING;
for(SubCategory subCategory : mValues.get(position).getSubCategories()){
subTitle = subTitle.concat(subCategory.getTitle()+ ", ");
}
if ( !subTitle.isEmpty() && subTitle.charAt(subTitle.length() - 2) == ',') {
subTitle = subTitle.substring(0, subTitle.length() - 2);
}
holder.description.setText(subTitle);
}
Picasso.with(holder.mThumb.getContext()).load("http:"+mValues.get(position).getCategoryImage().
getUrl()).placeholder(R.drawable.placeholder).into(holder.mThumb);
holder.mView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (null != mListener) {
// Notify the active callbacks interface (the activity, if the
// fragment is attached to one) that an item has been selected.
mListener.onCategoryListInteraction(holder.mItem);
}
}
});
}
@Override
public int getItemCount() {
return mValues.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
public final View mView;
public final TextView mCategoryView;
public final TextView description;
public final ImageView mThumb;
public Category mItem;
public ViewHolder(View view) {
super(view);
mView = view;
mCategoryView = (TextView) view.findViewById(R.id.cateogry_title);
description = (TextView) view.findViewById(R.id.cateogry_desc);
mThumb = view.findViewById(R.id.cateogry_icon);
}
@Override
public String toString() {
return super.toString() + " '" + description.getText() + "'";
}
}
}
你正在检查字幕是否为空:
if ( !subTitle.isEmpty() && subTitle.charAt(subTitle.length() - 2) == ',') {
subTitle = subTitle.substring(0, subTitle.length() - 2);
}
但是错误表明在某些情况下它是null,你没有检查:
if ( subTitle!= null && !subTitle.isEmpty() && subTitle.charAt(subTitle.length() - 2) == ',') {
subTitle = subTitle.substring(0, subTitle.length() - 2);
}