java - 使用volley将BLOB图像从mysql显示到android(json编码)

Question

请前辈帮我看看下面提到的代码，此代码只能显示文本数据，但不能显示图像，请帮助我。我还想显示带有文本数据的图像，但我失败了。基本上我使用回收 View 来显示带有 blob 图像的 MySQL 数据。请帮助我

php代码

    <?php

if ($_SERVER['REQUEST_METHOD']=='GET') {

    include 'DatabaseConfig.php';

    // Create connection
    $conn = mysqli_connect($dbhost,$dbuser,$dbpass,$dbname);

    //Checking if any error occured while connecting
 // Check connection
if ($conn->connect_error) {die("Connection failed: " . $conn->connect_error);}

// Query to run
$query = mysqli_query($conn, 'SELECT * FROM  customers_recovery.customer_registration');
// Create empty array to hold query results
$customelist = [];

// Loop through query and push results into $someArray;
while ($i = mysqli_fetch_assoc($query)) {
   array_push($customelist, [
   //'id'   => $row['customer_id']
   'myid' => $i['customer_id'], 
   'mynam' => $i['customer_name'], 
   'myarea' => $i['area_id'], 
   'myproduct' => $i['product_id'], 
   'myhouse' => $i['house_no'],
   'myphone' => $i['phone_no'],
   'myaddress' => $i['address'], 
   //'mypic' =>   $i['picture']
   'mypic' => base64_encode($i['picture'])
   //'image' => base64_encode($row['image'])
   ]);}
 //displaying the result in json format 
   $jsonDATA = json_encode($customelist);
   echo $jsonDATA;
}
?>

在 Android 中创建客户列表

package customerrecovery.zaheer.app.activities;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;

import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.List;

import customerrecovery.zaheer.app.R;
import customerrecovery.zaheer.app.adapters.CustomerListAdapter;
import customerrecovery.zaheer.app.model.CustomerListBean;

import static customerrecovery.zaheer.app.common.RestfulIpService.customer_register_get_url;

public class CustomersList extends AppCompatActivity {

    RecyclerView recyclerView;
    List<CustomerListBean> mycustomerlist ;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_customers_list);

        recyclerView = (RecyclerView)findViewById(R.id.recylcerView);
        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));

        mycustomerlist = new ArrayList<>();
        loadProducts();
    }

        private void loadProducts() {

            /*
             * Creating a String Request
             * The request type is GET defined by first parameter
             * The URL is defined in the second parameter
             * Then we have a Response Listener and a Error Listener
             * In response listener we will get the JSON response as a String
             * */
            StringRequest stringRequest = new StringRequest(Request.Method.GET, customer_register_get_url,
                    new Response.Listener<String>() {
                        @Override
                        public void onResponse(String response) {
                            try {
                                //converting the string to json array object
                                JSONArray array = new JSONArray(response);

                                //traversing through all the object
                                for (int i = 0; i < array.length(); i++) {

                                    //getting product object from json array
                                    JSONObject jsonData = array.getJSONObject(i);

                                    //adding the product to product list
                                    mycustomerlist.add(new CustomerListBean(
                                            jsonData.getString("myid"),
                                            jsonData.getString("mynam"),
                                            jsonData.getString("myarea"),
                                            jsonData.getString("myproduct"),
                                            jsonData.getString("myhouse"),
                                            jsonData.getString("myphone"),
                                            jsonData.getString("myaddress"),
                                            jsonData.optString("mypic")
                                    ));
                                }

                                //creating adapter object and setting it to recyclerview
                                CustomerListAdapter adapter = new CustomerListAdapter(CustomersList.this, mycustomerlist);
                                recyclerView.setAdapter(adapter);
                            } catch (JSONException e) {
                                e.printStackTrace();
                            }
                        }
                    },
                    new Response.ErrorListener() {
                        @Override
                        public void onErrorResponse(VolleyError error) {

                        }
                    });

            //adding our stringrequest to queue
            Volley.newRequestQueue(this).add(stringRequest);
        }
}

Android中获取json数据的Bean类

package customerrecovery.zaheer.app.model;

import java.sql.Blob;

public class CustomerListBean {

    private String cid;
    private String cnam;
    private String carea;
    private String cproduct;
    private String chouse;
    private String cphone;
    private String caddress;
    private String cpic;


    public CustomerListBean(String cid, String cnam, String carea, String cproduct, String chouse, String cphone, String caddress, String cpic) {
        this.cid = cid;
        this.cnam = cnam;
        this.carea = carea;
        this.cproduct = cproduct;
        this.chouse = chouse;
        this.cphone = cphone;
        this.caddress = caddress;
        this.cpic = cpic;
    }

    public String getCid() {
        return cid;
    }



    public String getCnam() {
        return cnam;
    }



    public String getCarea() {
        return carea;
    }


    public String getCproduct() {
        return cproduct;
    }


    public String getChouse() {
        return chouse;
    }


    public String getCphone() {
        return cphone;
    }


    public String getCaddress() {
        return caddress;
    }


    public String getCpic() { return cpic; }
/*
    public void setCpic(String cpic) {
        this.cpic = cpic;
    }*/
}

最后在android中制作Adapter类来显示数据

package customerrecovery.zaheer.app.adapters;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.util.Base64;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import com.bumptech.glide.Glide;

import java.util.List;

import customerrecovery.zaheer.app.R;
import customerrecovery.zaheer.app.model.CustomerListBean;

public class CustomerListAdapter extends RecyclerView.Adapter<CustomerListAdapter.CustomerListViewHolder> {

    private Context mCtx;
    private List<CustomerListBean> mycustomerlist;

    public CustomerListAdapter(Context mCtx, List<CustomerListBean> mycustomerlist) {
        this.mCtx = mCtx;
        this.mycustomerlist = mycustomerlist;
    }


    @NonNull
    @Override
    public CustomerListViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int viewType) {

        LayoutInflater inflater = LayoutInflater.from(mCtx);
        View view = inflater.inflate(R.layout.customer_list_row, null);
        return new CustomerListViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull CustomerListViewHolder viewHolder, int position) {

        CustomerListBean CustomerlistBean = mycustomerlist.get(position);

        //loading the image
        /*Glide.with(mCtx)
                .load(product.getImage())
                .into(holder.imageView);*/
        //viewHolder..setText(CustomerlistBean.getCnam());
        //viewHolder.textView.setText(CustomerlistBean.getCpic());
        //convert the image string int bytes like this



        viewHolder.customer_name.setText(CustomerlistBean.getCnam());
        viewHolder.customer_id.setText(CustomerlistBean.getCid());
        viewHolder.area_id.setText(CustomerlistBean.getCarea());
        viewHolder.product_id.setText(CustomerlistBean.getCproduct());
        viewHolder.house_no.setText(CustomerlistBean.getChouse());
        viewHolder.phone_no.setText(CustomerlistBean.getCphone());
        viewHolder.address.setText(CustomerlistBean.getCaddress());
//        Glide.with(mCtx).load(CustomerlistBean.getCpic()).into(viewHolder.imageView);
        try {
            byte[] decodedString = Base64.decode(CustomerlistBean.getCpic(), Base64.DEFAULT);
            Bitmap imgBitMap = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);
            //Glide.with(mCtx).load(imgBitMap).into(viewHolder.imageView);
        viewHolder.imageView.setImageBitmap(imgBitMap);
       // viewHolder.imageView.invalidate();
    } catch (Exception e) {
        e.printStackTrace();
    }

    }

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


    class CustomerListViewHolder extends RecyclerView.ViewHolder {

        TextView customer_id, customer_name, area_id, product_id, house_no, phone_no, address;
        ImageView imageView;

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

            customer_name = itemView.findViewById(R.id.cNam);
            customer_id = itemView.findViewById(R.id.cId);
            area_id = itemView.findViewById(R.id.cArea);
            product_id = itemView.findViewById(R.id.cProduct);
            house_no = itemView.findViewById(R.id.cHouse);
            phone_no = itemView.findViewById(R.id.cPhone);
            address = itemView.findViewById(R.id.cAddress);
            //imageView = itemView.findViewById(R.id.imageView);
        }
    }
}

Answer 1

尝试理解这一点，但这是我用于我的应用程序的代码

对于我的模型，正如您所说的 bean 类

public class Categories {
private String categoryId,categoryName, categoryImage;

public String getCategoryImage() {
    return categoryImage;
}

public void setCategoryImage(String categoryImage) {
    this.categoryImage = categoryImage;
}

public String getCategoryId() {
    return categoryId;
}

public void setCategoryId(String categoryId) {
    this.categoryId = categoryId;
}

public String getCategoryName() {
    return categoryName;
}

public void setCategoryName(String categoryName) {
    this.categoryName = categoryName;
}

public Categories(String categoryId, String categoryName, String categoryImage) {
    this.categoryId = categoryId;
    this.categoryName = categoryName;
    this.categoryImage = categoryImage;
}

public Categories(){

    }

}

然后在我的 Activity 课上，这就是我所做的

public class DashboardActivity extends AppCompatActivity
    implements NavigationView.OnNavigationItemSelectedListener, 
CategoryAdapter.ItemClickListener {

private View rootView;

private ArrayList<Categories> categoryList;
private CategoryAdapter adapter;
private RecyclerView recyclerView;

private ProgressDialog loading;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_dashboard);
    Toolbar toolbar = findViewById(R.id.toolbar);
    toolbar.setTitle("Dashboard");
    setSupportActionBar(toolbar);

    recyclerView = findViewById(R.id.dashboard_recycler);

    //Initializing the Categories list
    categoryList = new ArrayList<>();
    adapter = new CategoryAdapter(getApplicationContext(), categoryList, this);

    RecyclerView.LayoutManager mLayoutManager = new GridLayoutManager(getApplicationContext(), 2);
    recyclerView.setLayoutManager(mLayoutManager);
    recyclerView.setItemAnimator(new DefaultItemAnimator());
    recyclerView.setAdapter(adapter);

    fetchData();

}

@Override
protected void onResume(){
    super.onResume();
    fab.setCount(new Database(this).getCount());

}

private void fetchData() {
    loading = new ProgressDialog(this);
    loading.setMessage("Please wait...");
    loading.show();

    StringRequest req = new StringRequest(ServerURLs.ALL__CATEGORIES_URL,
            new Response.Listener<String>() {
                @Override
                public void onResponse(String response) {
                    Log.d("Our response is ", response);
                    loading.hide();
                    loading.dismiss();
                    loading = null;
                    categoryList.clear();
                    try {
                        JSONObject jsonObject = new JSONObject(response);
                        JSONArray result = jsonObject.getJSONArray(ServerURLs.JSON_ARRAY);
                        ArrayList<Categories> categories = new ArrayList<>();
                        for (int i = 0; i < result.length(); i++) {
                            JSONObject data = result.getJSONObject(i);
                            Categories categoryModel = new Categories();
                            categoryModel.setCategoryId(data.optString("category_id"));
                            categoryModel.setCategoryImage(data.optString ("image"));
                            categoryModel.setCategoryName(data.optString("category_name"));
                            categoryList.add(categoryModel);
                        }

                    } catch (JSONException e) {
                        Log.e("SRD", "Json parsing error: " + e.getMessage());
                        e.printStackTrace();
                    }


                    adapter.notifyDataSetChanged();
                }
            }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {

            if (error instanceof NetworkError) {
                loading.dismiss();
                new AlertDialog.Builder(DashboardActivity.this)
                        .setTitle("No Internet Connection")
                        .setMessage("Please connect to the Internet")
                        .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int which) {
                                fetchData();

                            }
                        }).setIcon(android.R.drawable.ic_dialog_alert).show();

            }

            else if (error instanceof TimeoutError) {
                loading.dismiss();
                new AlertDialog.Builder(DashboardActivity.this)
                        .setTitle("No Internet Connection")
                        .setMessage("It looks like your're having a problem with your internet connection and try again")
                        .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int which) {
                                fetchData();

                            }
                        }).setIcon(android.R.drawable.ic_dialog_alert).show();
            }

            else if (error instanceof NoConnectionError) {
                loading.dismiss();
                new AlertDialog.Builder(DashboardActivity.this)
                        .setTitle("Failed to connect to Server")
                        .setMessage("Check if you have Internet Access")
                        .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int which) {
                                fetchData();

                            }
                        }).setIcon(android.R.drawable.ic_dialog_alert).show();
            }
            Log.e("SRD", "Error: " + error.getMessage());
            loading.dismiss();
            loading = null;
        }
    });

    // Adding request to request queue
   Controller.getInstance().addToRequestQueue(req);
    }
}

最后是我的适配器类

public class CategoryAdapter extends 
RecyclerView.Adapter<CategoryAdapter.MyViewHolder> {
public Context context;
private Context mContext;

private List<Categories> categories;
private ItemClickListener onItemClickListener;

public CategoryAdapter(Context context, List<Categories> categories, ItemClickListener onItemClickListener){
    //Getting all the categories
    mContext = context;
    this.categories = categories;
    this.onItemClickListener = onItemClickListener;
}

public class MyViewHolder extends RecyclerView.ViewHolder {
    public ImageView category_image;
    public TextView category_name;

    public MyViewHolder(View view) {
        super(view);
        category_image =  view.findViewById(R.id.category_image);
        category_name = view.findViewById(R.id.category_name);
    }
}

@Override
public CategoryAdapter.MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.category_menu, parent, false );
    MyViewHolder viewHolder = new MyViewHolder(view);
    return viewHolder;
}

@Override
public void onBindViewHolder(final CategoryAdapter.MyViewHolder holder, int position) {
    final Categories category = categories.get(position);
    byte[] decodedString = Base64.decode(category.getCategoryImage(), Base64.DEFAULT);

    Glide.with(mContext)
            .load(decodedString)
            .thumbnail(0.5f)
            .crossFade()
            .fitCenter()
            .diskCacheStrategy(DiskCacheStrategy.ALL)
            .into(holder.category_image);

    ViewCompat.setTransitionName(holder.category_image, String.valueOf(decodedString));
    ViewCompat.setTransitionName(holder.category_name, category.getCategoryName());
    holder.category_name.setText(category.getCategoryName());
    holder.itemView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            onItemClickListener.onItemClick(holder.getAdapterPosition(), category , holder.category_image, holder.category_name);
        }
    });


}

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

public interface ItemClickListener {
    void onItemClick(int pos, Categories categoryItem, ImageView shareImageView, TextView mTextView);
    }

}

差不多就这些了。希望对您有帮助。