php - 使用 mysql 连接 android 和 php 时发生错误

Question

我的 post_item.java 文件中有以下代码:

package com.iwantnew.www;

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

import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class post_item extends Activity {
    private ProgressDialog pDialog;
    JSONParser jsonParser = new JSONParser();
    Button add_room;
    EditText contact_no;
    EditText no_of_room;
    EditText price_per_room;
    EditText description;

    private static String url_create_product = "http://10.0.2.2/android_iwant/android_add_room.php";

    private static final String TAG_SUCCESS = "success";

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

        //contact_no = (EditText) findViewById(R.id.contact_no);
        no_of_room = (EditText) findViewById(R.id.no_of_room);
        price_per_room = (EditText) findViewById(R.id.price_per_room);
        //description = (EditText) findViewById(R.id.description);
        contact_no = (EditText) findViewById(R.id.contact_no);

        add_room = (Button) findViewById(R.id.add_room);

        add_room.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // creating new product in background thread
                new add_new_room().execute();
            }
        });
    }
// suru...
    class add_new_room extends AsyncTask<String, String, String> {

        /**
         * Before starting background thread Show Progress Dialog
         * */
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(post_item.this);
            pDialog.setMessage("Saving details..");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(true);
            pDialog.show();
        }

        /**
         * Creating product
         * */
        protected String doInBackground(String... args) {
            //String contact = contact_no.getText().toString();
            String quantity = no_of_room.getText().toString();
            String price = price_per_room.getText().toString();
            //String contact = contact_no.getText().toString();
            String descriptions = description.getText().toString();

            // Building Parameters
            List<NameValuePair> params = new ArrayList<NameValuePair>();
            //params.add(new BasicNameValuePair("contact", contact));
            params.add(new BasicNameValuePair("quantity", quantity));
            params.add(new BasicNameValuePair("price", price));
            params.add(new BasicNameValuePair("descriptions", descriptions));

            // getting JSON Object
            // Note that create product url accepts POST method
            JSONObject json = jsonParser.makeHttpRequest(url_create_product,
                    "POST", params);

            // check log cat fro response

            Log.d("Create Response", json.toString());

            // check for success tag
            try {
                int success = json.getInt(TAG_SUCCESS);

                if (success == 1) {
                    // successfully created product
                    Intent i = new Intent(getApplicationContext(), MainActivity.class);
                    startActivity(i);

                    // closing this screen
                    finish();
                } else {
                    // failed to create product
                }
            } catch (JSONException e) {
                e.printStackTrace();
            }

            return null;
        }

        /**
         * After completing background task Dismiss the progress dialog
         * **/
        protected void onPostExecute(String file_url) {
            // dismiss the dialog once done
            pDialog.dismiss();
        }

    }
}

而且，我的 php 文件中有以下内容:

<?php

/*
* Following code will create a new product row
* All product details are read from HTTP Post Request
*/

// array for JSON response
$response = array();

// check for required fields

if (isset($_POST['quantity']) &&  isset($_POST['price'])) {

    //$location = $_POST['location'];
    $quantity = $_POST['quantity'];
    $price = $_POST['price'];
    //$productID = $_POST['area'];
    //$contact = $_POST['contact'];
    $descriptions = $_POST['descriptions'];

    // include db connect class
   require_once __DIR__ . '/db_connect.php';

    // connecting to db
    $db = new DB_CONNECT();

    // mysql inserting a new row
      $result = mysql_query("INSERT INTO room_tb(uid,categoryID,quantity,price,description) VALUES(5,1,'$quantity','$price','$descriptions')");
    //$result1 = mysql_query("INSERT INTO users(userContactNumber) VALUES('$contact')");

    // check if row inserted or not
    if($result)/*&& ($result1)*/ {
        // successfully inserted into database
        $response["success"] = 1;
        $response["message"] = "Room added successfully.";

        // echoing JSON response
        echo json_encode($response);
    } else {
        // failed to insert row
        $response["success"] = 0;
        $response["message"] = "Oops! An error occurred.";

        // echoing JSON response
        echo json_encode($response);
    }
} else {
    // required field is missing
    $response["success"] = 0;
    $response["message"] = "Required field(s) is missing";

    // echoing JSON response
    echo json_encode($response);
}
?>

每当我将描述或联系电话发送到数据库时，Android模拟器都会说“意外停止工作”，并且没有记录进入数据库。但是，如果我只传递 quantity、price、categoryID 和 uid，则不会发生错误并记录转到数据库。我做错了什么？

这是我的日志猫 http://pastebin.com/WvBPs2gs 的链接

Answer 1

Caused by: java.lang.NullPointerException
07-15 02:06:36.366: E/AndroidRuntime(2918):     at    com.iwantnew.www.post_item$add_new_room.doInBackground(post_item.java:96)

因此，无论第 96 行有什么内容，它都是空的，应该进行检查。您的代码 fragment 中没有行号，但我认为这与描述变量的使用有关:

String descriptions = description.getText().toString();

而变量描述的赋值在注释中设置

//description = (EditText) findViewById(R.id.description);