如何将ListView中的TextView传递回PHP

Question

For this function, I need to pass the item mentioned in the custom listview from Activity1.java back to php in order to retrieve more information (including image via Picasso library) about that particular item in another activity from mysql, so may I know whether the php file is correct and how should I open Activity2.java .

Activity1.java

public class Activity1 extends AppCompatActivity{

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    ListView lv= (ListView) findViewById(R.id.listview);
    lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int pos, long id) {
            String name =((TextView) findViewById(R.id.itemname)).getText().toString();
            Intent intent = new Intent(Activity1.this, Activity2.class);
            intent.putExtra("NAME", name);
            startActivity(intent);
        }
    });
}

}

Detail.php

<?php
include 'dbConnect.php';
mysqli_set_charset($conn, 'utf8');
$NAME = $_POST['NAME'];

$sql = "SELECT * FROM items WHERE item_name = '$NAME'" ;
result = $conn->query($sql);

if ($result->num_rows >0) {
    while($row[] = $result->fetch_assoc()) {
        $tem = $row;
        $json = json_encode($tem);  
    }
} else {
     echo "No Results Found.";
}
echo $json;
$conn->close();
?>

Answer 1

I would recommend you to use Retrofit 2 library for making REST requests, which is exactly what you need.

First add following dependencies to your build.gradle file

dependencies {  
    // Retrofit & OkHttp
    compile 'com.squareup.retrofit2:retrofit:2.3.0'

    // JSON Converter
    compile 'com.squareup.retrofit2:converter-gson:2.3.0'
}

You will need to make an interface to describe your Retrofit service. In your case it would look something like this (dont put / at the beginning of the path):

public interface PhpService {
    @FormUrlEncoded
    @POST("path/to/your/web/resource")
    Call<Item> searchForItem(@Field("NAME") String itemName);
}

You need to make a class describing your item (you will have to write that class yourself, as I dont know actual fields):

class Item {
    @SerializedName("name")
    String name;

    @SerializedName("url")
    String imageUrl;
}

Now you need to create actual service like so (replace baseUrl with your website):

Retrofit retrofit = new Retrofit.Builder()
.baseUrl("https://yourwebsite.com/")
.build();

PhpService service = retrofit.create(PhpService.class);

Now, using created service you can make a request to your php webserver:

Call<Item> item = service.searchForItem("yourItemName");

call.enqueue(new Callback<Item>() {  
   @Override
   public void onResponse(Call<Item> call, Response<Item> response) {
       if (response.isSuccessful()) {
           Itemitem = response.body();
           // todo do stuff with your item
       }
   }

   @Override
   public void onFailure(Call<Item> call, Throwable t) {
       // the network call was a failure
       // TODO: handle error
    }
});

That should be all to get item from your php script.

If you need more help check out this tutorial by futurestud.io .