Question

我在尝试从Parse.com（后端数据库）提取数据时遇到此错误。

错误是说Businesses类中的put函数不为null。我不确定这意味着什么，因为它不是假设不是空的？我想显示企业的名称，所以名称必须在那里才能做到这一点吗？

或者是说其他词中的值不能为空？

FATAL EXCEPTION: main
    Process: zafir.com.app, PID: 13295
    java.lang.IllegalArgumentException: value may not be null.
        at com.parse.ParseObject.performPut(ParseObject.java:2918)
        at com.parse.ParseObject.put(ParseObject.java:2909)
        at zafir.com.app.Businesses.setName(Businesses.java:20)
        at zafir.com.app.Fragments.Categories$1.done(Categories.java:57)
        at zafir.com.app.Fragments.Categories$1.done(Categories.java:50)
        at com.parse.ParseTaskUtils$2$1.run(ParseTaskUtils.java:115)
        at android.os.Handler.handleCallback(Handler.java:739)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:135)
        at android.app.ActivityThread.main(ActivityThread.java:5283)
        at java.lang.reflect.Method.invoke(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:372)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:904)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:699)

企业

package zafir.com.app;

import com.parse.ParseClassName;
import com.parse.ParseObject;


@ParseClassName("Businesses")
public class Businesses extends ParseObject
{

    private String Name;

    public String getName()
    {
        return getString("Name");
    }

    public void setName(String name)
    {
        put("Name", name);
    }

    public String getCategory()
    {
        return getString("Category");
    }

    public void setCategory(String category)
    {
        put("Category", category);
    }

    public String getEmail()
    {
        return getString("Email");
    }

    public void setEmail(String email)
    {
        put("Email", email);
    }

    public String getLocation()
    {
        return getString("Location");
    }

    public void setLocation(String location)
    {
        put("Location", location);
    }

    public String getPhone()
    {
        return getString("Phone");
    }

    public void setPhone(String phone)
    {
        put("Phone", phone);
    }

    public String getWebsite()
    {
        return getString("Website");
    }

    public void setWebsite(String website)
    {
        put("Website", website);
    }
}

分类

    public class Categories extends Fragment
{

    List<Businesses> data = new ArrayList<>();
    private RecyclerView recView = null;
    private RecyclerAdapter zAdapter;

    public Categories()
    {
        // Required empty public constructor
    }



    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
    {

        ParseQuery<Businesses> query = new ParseQuery<>("Businesses");
        query.findInBackground(new FindCallback<Businesses>()
        {
            @Override
            public void done(List<Businesses> list, ParseException e)
            {
                if(e == null)
                {
                    for(Businesses businesses : list)
                    {
                        Businesses bizList = new Businesses();
                        bizList.setName(businesses.getName());
                        bizList.setPhone(businesses.getPhone());
                        bizList.setEmail(businesses.getEmail());
                        bizList.setWebsite(businesses.getWebsite());
                        bizList.setLocation(businesses.getLocation());
                        bizList.setCategory(businesses.getCategory());
                        data.add(bizList);
                    }
                }
            }
        });

        View rootView = inflater.inflate(R.layout.fragment_categories, container, false);

        recView = (RecyclerView) rootView.findViewById(R.id.recview_categories);
        recView.setLayoutManager(new LinearLayoutManager(getActivity()));
        recView.setAdapter(zAdapter);

        return inflater.inflate(R.layout.fragment_categories, container, false);
    }

}

RecyclerAdapter

    public static class ViewHolder extends RecyclerView.ViewHolder
    {
        public TextView zName;
        public TextView zPhone;
        public TextView zEmail;
        public TextView zWebsite;
        public TextView zLocation;
        public TextView zCategory;

        public ViewHolder(View itemView)
        {
            super(itemView);

            zName = (TextView) itemView.findViewById(R.id.name);
            zPhone = (TextView) itemView.findViewById(R.id.phone);
            zEmail = (TextView) itemView.findViewById(R.id.email);
            zWebsite = (TextView) itemView.findViewById(R.id.website);
            zLocation = (TextView) itemView.findViewById(R.id.location);
            zCategory = (TextView) itemView.findViewById(R.id.category);
        }
    }

    public RecyclerAdapter(Context context,List<Businesses> data)
    {
        inflater=LayoutInflater.from(context);
        this.data= data;
    }

    @Override
    public RecyclerAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType)
    {
        Context context = parent.getContext();
        LayoutInflater inflater = LayoutInflater.from(context);

        View recView = inflater.inflate(R.layout.recycler_layout, parent, false);

        ViewHolder ViewHolder = new ViewHolder(recView);

        return ViewHolder;
    }

    @Override
    public void onBindViewHolder(RecyclerAdapter.ViewHolder viewHolder, int position)
    {
        Businesses businesses = data.get(position);

        TextView name = viewHolder.zName;
        name.setText(businesses.getName());

        TextView phone = viewHolder.zPhone;
        phone.setText(businesses.getPhone());

        TextView email = viewHolder.zEmail;
        email.setText(businesses.getEmail());

        TextView website = viewHolder.zWebsite;
        website.setText(businesses.getWebsite());

        TextView location = viewHolder.zLocation;
        location.setText(businesses.getLocation());

        TextView category = viewHolder.zCategory;
        category.setText(businesses.getCategory());
    }

    @Override
    public int getItemCount()
    {
        return data.size();
    }
}

Answer 1

在旁边方法的类别类中更改此代码。

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
    {

        ParseQuery<Businesses> query = new ParseQuery<>("Businesses");
        query.findInBackground(new FindCallback<Businesses>()
        {
            @Override
            public void done(List<Businesses> list, ParseException e)
            {
                if(e == null)
                {
                    for(Businesses businesses : list)
                    {
                        Businesses bizList = new Businesses();
                        bizList.setName(businesses.getName());
                        bizList.setPhone(businesses.getPhone());
                        bizList.setEmail(businesses.getEmail());
                        bizList.setWebsite(businesses.getWebsite());
                        bizList.setLocation(businesses.getLocation());
                        bizList.setCategory(businesses.getCategory());
                        data.add(bizList);
                    }
//find in background is one type of thered so when data is added into array list then u can bind your adapter
                    View rootView = inflater.inflate(R.layout.fragment_categories, container, false);

                    recView = (RecyclerView) rootView.findViewById(R.id.recview_categories);
                    recView.setLayoutManager(new LinearLayoutManager(getActivity()));
                    recView.setAdapter(zAdapter);

                    return inflater.inflate(R.layout.fragment_categories, container, false);
                }
            }
        });


    }

}

java.lang.IllegalArgumentException：value不能为null

1 个答案: