使用Android / Java从嵌套对象Firebase中检索数据？

问题描述

您好我是Firebase的新手。这是我的数据看起来像

我想知道我怎么能从零售商检索distributorInfo。我试图从FirebaseRecyclerAdapter的populateViewHolder方法检索distributorInfo。我能够得到所选项目的关键。如何得到distributorInfo里面的信息？

  private void getRetailers（）{
 FirebaseRecyclerAdapter< RetailerInfo，RetailerViewHolder> （
 RetailerInfo.class，
 R.layout.distributor_row，
 RetailerViewHolder.class，
 mDatabase 
）{
 @Override 
 protected void populateViewHolder（RetailerViewHolder viewHolder，final RetailerInfo model，final int position）{
 
 viewHolder.setAddress（model.getContactPerson（））; 
 viewHolder.setArea（model.getContactNumber（））; 
 viewHolder.setShopName（model.getShopName（））; 
 viewHolder.setZipcode（model.getZipcode（））; 
 viewHolder.setCity（model.getCity（））; 
 
 $ b viewHolder.mView.setOnClickListener（new View.OnClickListener（）{
 @Override 
 public void onClick（View view）{
 
 // DatabaseReference ref = getRef（position）; 
 // String key = ref.getKey（）; 
 // Toast.makeText（Distributors.this，key，Toast.LENGTH_SHORT）.show（） ; 
 
 
 ValueEventListener valueEventListener = new ValueEventListener（）{
 $ b $ @Override 
 public void onDataChange（DataSnapshot dataSnapshot）{
 RetailerInfo retailerInfo = dataSnapshot.getValue（RetailerInfo.class）; 
 
 
 Iterator it = retailerInfo.getDistributorInfo（）。entrySet（）。iterator（）; 
 while（it.hasNext（）） {
 Map.Entry pair =（Map.Entry）it.next（）; 
 Log.d（TAG，distributorInfo：+ pair.getKey（）+=+ pair.getValue（））; 
 it.remove（）; //避免ConcurrentModificationException异常
 
 
 $ b @Override 
 public void onCancelled（DatabaseError databaseError）{
 
} 
 }; 
 
 
 mDatabase.addListenerForSingleValueEvent（valueEventListener）; 
 
} 
}）; 
} 
}; 
 
 recyclerView.setAdapter（adapter）; 
 
 $ / code> 

零售商信息代码： - $ /



公共类RetailerInfo {
字符串id，shopName，地址，城市，邮编，area，contactPerson，contactNumber，contact_person_email，location_master，type，last_vist，last_visited_by，cityName，salesPersonName;
HashMap distributorInfo;



  public RetailerInfo（）{
} 
 
 public RetailerInfo（String id，String shopName，String address，String city，String zipcode，String area，String contactPerson，String contactNumber，String contact_person_email，String location_master，String type，String last_vist，String last_visited_by，String cityName，String salesPersonName，HashMap< String ，String> distributorInfo）{
 this.id = id; 
 this.shopName = shopName; 
 this.address = address; 
 this.city = city; 
 this.zipcode = zipcode; 
 this.area = area; 
 this.contactPerson = contactPerson; 
 this.contactNumber = contactNumber; 
 this.contact_person_email = contact_person_email; 
 this.location_master = location_master; 
 this.type = type; 
 this.last_vist = last_vist; 
 this.last_visited_by = last_visited_by; 
 this.cityName = cityName; 
 this.salesPersonName = salesPersonName; 
 this.distributorInfo = distributorInfo; 
} 
 
 public HashMap< String，String> getDistributorInfo（）{
 return distributorInfo; 
} 
 
 public String getId（）{
 return id; 
} 
 
 public String getShopName（）{
 return shopName; 
} 
 
 public String getAddress（）{
 return address; 
} 
 
 public String getCity（）{
 return city; 
} 
 
 public String getZipcode（）{
 return zipcode; 
} 
 
 public String getArea（）{
 return area; 
} 
 
 public String getContactPerson（）{
 return contactPerson; 
 
 
 public String getContactNumber（）{
 return contactNumber; 
} 
 
 public String getContact_person_email（）{
 return contact_person_email; 
} 
 
 public String getLocation_master（）{
 return location_master; 
} 
 
 public String getType（）{
 return type; 
} 
 
 public String getLast_vist（）{
 return last_vist; 
} 
 
 public String getLast_visited_by（）{
 return last_visited_by; 
} 
 
 public String getCityName（）{
 return cityName; 
} 
 
 public String getSalesPersonName（）{
 return salesPersonName; 
} 
 
 public void setId（String id）{
 this.id = id; 
} 
 
 public void setShopName（String shopName）{
 this.shopName = shopName; 
 
 $ b $ public void setAddress（String address）{
 this.address = address; 
} 
 
 public void setCity（String city）{
 this.city = city; 
} 
 
 public void setZipcode（String zipcode）{
 this.zipcode = zipcode; 
} 
 
 public void setArea（String area）{
 this.area = area; 
} 
 
 public void setContactPerson（String contactPerson）{
 this.contactPerson = contactPerson; 
 
 
 public void setContactNumber（String contactNumber）{
 this.contactNumber = contactNumber; 
} 
 
 public void setContact_person_email（String contact_person_email）{
 this.contact_person_email = contact_person_email; 
} 
 
 public void setLocation_master（String location_master）{
 this.location_master = location_master; 
} 
 
 public void setType（String type）{
 this.type = type; 
 
 
 public void setLast_vist（String last_vist）{
 this.last_vist = last_vist; 
} 
 
 public void setLast_visited_by（String last_visited_by）{
 this.last_visited_by = last_visited_by; 
} 
 
 public void setCityName（String cityName）{
 this.cityName = cityName; 
} 
 
 public void setSalesPersonName（String salesPersonName）{
 this.salesPersonName = salesPersonName; 
 
 
 $ / code $ / pre 
 
 
感谢您的任何帮助或建议。谢谢。 / b> 
 
解决方案
例如，您也可以嵌套您的对象：
 
 
 公共类零售商{
字符串地址，区域，城市，联系人编号，联系人，shopName，zipCode; 
 DistributorInfo distributorInfo; 
 
公共零售商（...）{
 //构造函数
} 
 //吸气和吸气器
} 
 
 public class DistributorInfo {
 //所有字段，构造函数，getter和setter 
} 
  
 
 
  
  




Hi I am a newbie to Firebase .This is how my data looks like

I would like to know how I can retrieve the distributorInfo from retailers.I am trying to retrieve distributorInfo from a FirebaseRecyclerAdapter's populateViewHolder method.I am able to get the key for the selected item.How do I get the information inside distributorInfo?

 private void getRetailers() {
        FirebaseRecyclerAdapter<RetailerInfo,RetailerViewHolder> adapter = new FirebaseRecyclerAdapter<RetailerInfo, RetailerViewHolder>(
                RetailerInfo.class,
                R.layout.distributor_row,
                RetailerViewHolder.class,
                mDatabase
        ) {
            @Override
            protected void populateViewHolder(RetailerViewHolder viewHolder, final RetailerInfo model, final int position) {

                viewHolder.setAddress(model.getContactPerson());
                viewHolder.setArea(model.getContactNumber());
                viewHolder.setShopName(model.getShopName());
                viewHolder.setZipcode(model.getZipcode());
                viewHolder.setCity(model.getCity());


                viewHolder.mView.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {

//                        DatabaseReference ref = getRef(position);
//                        String key=   ref.getKey();
//                        Toast.makeText(Distributors.this, key, Toast.LENGTH_SHORT).show();


                        ValueEventListener valueEventListener = new ValueEventListener() {

                            @Override
                            public void onDataChange(DataSnapshot dataSnapshot) {
                                RetailerInfo retailerInfo = dataSnapshot.getValue(RetailerInfo.class);


                                Iterator it = retailerInfo.getDistributorInfo().entrySet().iterator();
                                while (it.hasNext()) {
                                    Map.Entry pair = (Map.Entry)it.next();
                                    Log.d("TAG","distributorInfo: "+pair.getKey() +  " = "  + pair.getValue());
                                    it.remove(); // avoids a ConcurrentModificationException
                                }
                            }

                            @Override
                            public void onCancelled(DatabaseError databaseError) {

                            }
                        };


                        mDatabase.addListenerForSingleValueEvent(valueEventListener);

                    }
                });
            }
        };

        recyclerView.setAdapter(adapter);
    }

Code for RetailerInfo :-

public class RetailerInfo { String id, shopName,address,city,zipcode,area, contactPerson, contactNumber,contact_person_email,location_master,type,last_vist,last_visited_by,cityName,salesPersonName; HashMap distributorInfo;

    public RetailerInfo() {
    }

    public RetailerInfo(String id, String shopName, String address, String city, String zipcode, String area, String contactPerson, String contactNumber, String contact_person_email, String location_master, String type, String last_vist, String last_visited_by, String cityName, String salesPersonName, HashMap<String, String> distributorInfo) {
        this.id = id;
        this.shopName = shopName;
        this.address = address;
        this.city = city;
        this.zipcode = zipcode;
        this.area = area;
        this.contactPerson = contactPerson;
        this.contactNumber = contactNumber;
        this.contact_person_email = contact_person_email;
        this.location_master = location_master;
        this.type = type;
        this.last_vist = last_vist;
        this.last_visited_by = last_visited_by;
        this.cityName = cityName;
        this.salesPersonName = salesPersonName;
        this.distributorInfo = distributorInfo;
    }

    public HashMap<String, String> getDistributorInfo() {
        return distributorInfo;
    }

    public String getId() {
        return id;
    }

    public String getShopName() {
        return shopName;
    }

    public String getAddress() {
        return address;
    }

    public String getCity() {
        return city;
    }

    public String getZipcode() {
        return zipcode;
    }

    public String getArea() {
        return area;
    }

    public String getContactPerson() {
        return contactPerson;
    }

    public String getContactNumber() {
        return contactNumber;
    }

    public String getContact_person_email() {
        return contact_person_email;
    }

    public String getLocation_master() {
        return location_master;
    }

    public String getType() {
        return type;
    }

    public String getLast_vist() {
        return last_vist;
    }

    public String getLast_visited_by() {
        return last_visited_by;
    }

    public String getCityName() {
        return cityName;
    }

    public String getSalesPersonName() {
        return salesPersonName;
    }

    public void setId(String id) {
        this.id = id;
    }

    public void setShopName(String shopName) {
        this.shopName = shopName;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public void setCity(String city) {
        this.city = city;
    }

    public void setZipcode(String zipcode) {
        this.zipcode = zipcode;
    }

    public void setArea(String area) {
        this.area = area;
    }

    public void setContactPerson(String contactPerson) {
        this.contactPerson = contactPerson;
    }

    public void setContactNumber(String contactNumber) {
        this.contactNumber = contactNumber;
    }

    public void setContact_person_email(String contact_person_email) {
        this.contact_person_email = contact_person_email;
    }

    public void setLocation_master(String location_master) {
        this.location_master = location_master;
    }

    public void setType(String type) {
        this.type = type;
    }

    public void setLast_vist(String last_vist) {
        this.last_vist = last_vist;
    }

    public void setLast_visited_by(String last_visited_by) {
        this.last_visited_by = last_visited_by;
    }

    public void setCityName(String cityName) {
        this.cityName = cityName;
    }

    public void setSalesPersonName(String salesPersonName) {
        this.salesPersonName = salesPersonName;
    }
}

Any help or suggestion is appreciated.Thank you.

解决方案

You can for example nest your objects as well:

public class Retailer{
    String Address, area, city, contactNumber, contactPerson, shopName, zipCode;
    DistributorInfo distributorInfo;

    public Retailer(...){
        // Contructor
    }
    // Getter and setters
}

public class DistributorInfo {
    // all fields, constructor, getter and setters
}

usage:

Retailer retailerInfo = dataSnapshot.getValue(Retailer.class);

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