Question

我正在使用AsyncTask来显示通过PHP和JSON从数据库提供的数据，因此当我尝试用尽我的应用程序时，我得到了错误：

09-20 15:31:51.330: E/Buffer Error(4484): Error converting result java.lang.NullPointerException
09-20 15:31:51.330: E/JSON Parser(4484): Error parsing data org.json.JSONException: End of input at character 0 of

这是我的Java类：

package com.androidhive.dashboard;

import android.app.Activity;
import android.app.ListActivity;
import android.os.Bundle;
import androidhive.dashboard.R;

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

import org.apache.http.NameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;

public class PlacesActivity extends ListActivity {

    // Progress Dialog
    private ProgressDialog pDialog;

    // Creating JSON Parser object
    JSONParser jParser = new JSONParser();

    ArrayList<HashMap<String, String>> productsList;

    // url to get all products list
    private static String url_all_products = "http://192.168.1.74/test/focus.php";

    // JSON Node names
    private static final String TAG_SUCCESS = "success";
    private static final String TAG_PRODUCTS = "products";
    private static final String TAG_PID = "pid";
    private static final String LIB_ART = "LibArt";
    private static final String COD_ART = "CodArt";

    // products JSONArray
    JSONArray products = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.places_layout);

        // Hashmap for ListView
        productsList = new ArrayList<HashMap<String, String>>();

        // Loading products in Background Thread
        new LoadAllProducts().execute();

        // Get listview
        ListView lv = getListView();




    }//onCreate finish

 // Response from Edit Product Activity
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        // if result code 100
        if (resultCode == 100) {
            // if result code 100 is received 
            // means user edited/deleted product
            // reload this screen again
            Intent intent = getIntent();
            finish();
            startActivity(intent);
        }
    }

        /**
         * Background Async Task to Load all product by making HTTP Request
         * */
        class LoadAllProducts extends AsyncTask<String, String, String> {

            /**
             * Before starting background thread Show Progress Dialog
             * */
            @Override
            protected void onPreExecute() {
                super.onPreExecute();
                pDialog = new ProgressDialog(PlacesActivity.this);
                pDialog.setMessage("Loading products. Please wait...");
                pDialog.setIndeterminate(false);
                pDialog.setCancelable(false);
                pDialog.show();
            }

            /**
             * getting All products from url
             * */
            protected String doInBackground(String... args) {
                // Building Parameters
                List<NameValuePair> params = new ArrayList<NameValuePair>();
                // getting JSON string from URL
                JSONObject json = jParser.makeHttpRequest(url_all_products, "GET", params);

                // Check your log cat for JSON reponse
                Log.d("All Products: ", json.toString());

                try {
                    // Checking for SUCCESS TAG
                    int success = json.getInt(TAG_SUCCESS);

                    if (success == 1) {
                        // products found
                        // Getting Array of Products
                        products = json.getJSONArray(TAG_PRODUCTS);

                        // looping through All Products
                        for (int i = 0; i < products.length(); i++) {
                            JSONObject c = products.getJSONObject(i);

                            // Storing each json item in variable
                            String id = c.getString(TAG_PID);
                            String LibArt = c.getString(LIB_ART);
                            String CodArt = c.getString(COD_ART);

                            // creating new HashMap
                            HashMap<String, String> map = new HashMap<String, String>();

                            // adding each child node to HashMap key => value
                            map.put(TAG_PID, id);
                            map.put(LIB_ART, LibArt);
                            map.put(COD_ART,CodArt);

                            // adding HashList to ArrayList
                            productsList.add(map);
                        }
                    } 
                } catch (JSONException e) {
                    e.printStackTrace();
                }

                return null;
            }

            /**
             * After completing background task Dismiss the progress dialog
             * **/
            protected void onPostExecute(String file_url) {
                // dismiss the dialog after getting all products
                pDialog.dismiss();
                // updating UI from Background Thread
                runOnUiThread(new Runnable() {
                    public void run() {
                        /**
                         * Updating parsed JSON data into ListView
                         * */
                        ListAdapter adapter = new SimpleAdapter(
                                PlacesActivity.this, productsList,
                                R.layout.list_item, new String[] { COD_ART,TAG_PID,
                                        LIB_ART},
                                new int[] { R.id.codart ,R.id.pid, R.id.libart });
                        // updating listview
                        setListAdapter(adapter);
                    }
                });

            }

        }





}

这里是PHP文件：

<?php
require 'FastJSON.class.php';

$db = mssql_connect ('HPWALID', '', '');
$ret = mssql_select_db ('Focus', $db) or die ('Echec lors de la connexion: '.mysql_error ());
$result = mssql_query("SELECT * FROM TabStock");
if (mssql_num_rows($result) > 0) {
    // looping through all results
    // products node
    $response["products"] = array();

    while ($row = mssql_fetch_array($result)) {
        // temp user array
        $product = array();
        $product["CodArt"] = $row["CodArt"];
        $product["LibArt"] = $row["LibArt"];
        $product["pid"] = $row["pid"];      



        // push single product into final response array
        array_push($response["products"], $product);
    }
    // success
    $response["success"] = 1;

    // echoing JSON response
    $var = FastJSON::encode($response);
    echo $var;
} else {
    // no products found
    $response["success"] = 0;
    $response["message"] = "No products found";

    // echo no users JSON
   // echo json_encode($response);
   $var = FastJSON::encode($response);
   echo $var;
}


?>

Answer 1

如果您使用的是模拟器，请将您的IP地址（192.168.1.74）更改为（10.0.2.2）

相同的“解析数据org.json.JSONException错误”错误仍然跟着我

1 个答案: