String中不能转换到的JSONObject

String中不能转换到的JSONObject

本文介绍了java.lang.String中不能转换到的JSONObject的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

我试图从数据库中检索数据时面临的问题:

 错误解析数据org.json.JSONException:值< java.lang.String类型的DOCTYPE不能转换为JSONObject的!公共类AllProductsActivity扩展ListActivity {    //进度对话框
    私人ProgressDialog pDialog;    //创建JSON解析器对象
    JSONParser jParser =新JSONParser();    ArrayList的<&HashMap的LT;字符串,字符串>>产品列表;    // URL获得所有产品清单
    私人静态字符串url_all_products =htt​​p://192.168.1.3/android_connect/get_all_products.php;    // JSON节点名称
    私有静态最后弦乐TAG_SUCCESS =成功;
    私有静态最后弦乐TAG_PRODUCTS =产品;
    私有静态最后弦乐TAG_PID =PID;
    私有静态最后弦乐TAG_NAME =名;    //产品JSONArray
    JSONArray产品= NULL;    @覆盖
    公共无效的onCreate(捆绑savedInstanceState){
        super.onCreate(savedInstanceState);
        的setContentView(R.layout.all_products);        //为哈希映射的ListView
        产品列表=新的ArrayList<&HashMap的LT;字符串,字符串>>();        //装载产品在后台线程
        新LoadAllProducts()执行();        //获取列表视图
        ListView控件LV = getListView();        //在选课单品
        //启动编辑产品屏幕
        lv.setOnItemClickListener(新OnItemClickListener(){            @覆盖
            公共无效onItemClick(适配器视图<>母公司,观景,
                    INT位置,长的id){
                //从选定的ListItem得到的值
                字符串的pid =((的TextView)view.findViewById(R.id.pid))的getText()。
                        的ToString();                //开始新意图
                在意向=新意图(getApplicationContext()
                        EditProductActivity.class);
                //发送到PID下一个活动
                in.putExtra(TAG_PID,PID);                //开始新的活动,期待一些回响应
                startActivityForResult(在100);
            }
        });    }    //从编辑产品的活动响应
    @覆盖
    保护无效的onActivityResult(INT申请code,INT结果code,意图数据){
        super.onActivityResult(要求code,结果code,数据);
        //如果结果code 100
        如果(结果code == 100){
            //如果结果code 100接收
            //意味着用户编辑/删除产品
            //重新载入该画面
            意向意图= getIntent();
            完();
            startActivity(意向);
        }    }    / **
     *背景异步任务以通过HTTP请求负载的所有产品
     * * /
    类LoadAllProducts扩展的AsyncTask<字符串,字符串,字符串> {        / **
         *启动后台线程显示进度对话框之前
         * * /
        @覆盖
        在preExecute保护无效(){
            super.on preExecute();
            pDialog =新ProgressDialog(AllProductsActivity.this);
            pDialog.setMessage(加载产品请稍候......);
            pDialog.setIndeterminate(假);
            pDialog.setCancelable(假);
            pDialog.show();
        }        / **
         *让所有的产品网址
         * * /
        保护字符串doInBackground(字符串参数... args){
            //大厦参数
            清单<&的NameValuePair GT; PARAMS =新的ArrayList<&的NameValuePair GT;();            // URL从获取JSON字符串
            JSONObject的JSON = jParser.makeHtt prequest(url_all_products,GET,则params);            //检查JSON效应初探日志的猫
            Log.d(所有产品,json.toString());            尝试{
                //检查成功TAG
                INT成功= json.getInt(TAG_SUCCESS);                如果(成功== 1){
                    发现//产品
                    //获取产品阵列
                    产品= json.getJSONArray(TAG_PRODUCTS);                    //产品通过所有循环
                    的for(int i = 0; I< products.length();我++){
                        JSONObject的C = products.getJSONObject(I)                        //存储在变量中的每个JSON项目
                        字符串ID = c.getString(TAG_PID);
                        字符串名称= c.getString(TAG_NAME);                        //创建新的HashMap
                        HashMap的<字符串,字符串>地图=新的HashMap<字符串,字符串>();                        //将每个子节点的HashMap键=>值
                        map.put(TAG_PID,身份证);
                        map.put(TAG_NAME,名);                        //添加HashList到ArrayList的
                        productsList.add(地图);
                    }
                }其他{
                    //没有发现产品
                    //启动添加新产品活动
                    意图I =新意图(getApplicationContext()
                            NewProductActivity.class);
                    //关闭所有previous活动
                    i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                    startActivity(ⅰ);
                }
            }赶上(JSONException E){
                e.printStackTrace();
            }            返回null;
        }        / **
         *在完成后台任务之后辞退进度对话框
         * ** /
        保护无效onPostExecute(字符串FILE_URL){
            //让所有的产品后,关闭该对话框
            pDialog.dismiss();
            //从后台线程更新界面
            runOnUiThread(新的Runnable(){
                公共无效的run(){
                    / **
                     *更新解析JSON数据到ListView控件
                     * * /
                    ListAdapter适配器=新SimpleAdapter(
                            AllProductsActivity.this,产品列表,
                            R.layout.list_item,新的String [] {TAG_PID,
                                    TAG_NAME},
                            新的INT [] {R.id.pid,R.id.name});
                    //更新列表视图
                    setListAdapter(适配器);
                }
            });        }    }
}

问题是excatly触发执行这条线时:

  //获取JSON从URL字符串
    JSONObject的JSON = jParser.makeHtt prequest(url_all_products,GET,则params);

这是怎么回事与code?我想,我不是编码有些不妥。
任何帮助吗?

PHP文件:

 < PHP的头?('内容类型:应用程序/ JSON的;字符集= utf-8');
/ *
 *继code将列出所有产品
 * ///数组JSON响应
$响应=阵列();
//其中包括DB连接类
require_once __DIR__。 /db_connect.php';//连接到数据库
$ DB =新DB_CONNECT();//从产品表中的所有产品
$结果= mysql_query(SELECT * FROM产品)或死亡(mysql_error());//检查空结果
如果(mysql_num_rows($结果)大于0){
    //通过所有结果循环
    //产品节点
    $响应[产品] =阵列();    而($行= mysql_fetch_array($结果)){
        //临时用户阵
        $产品=阵列();
        $产品[PID] = $行[PID];
        $产品[名称] = $行[名称];
        $产品[价格] = $行[价格];
        $产品[说明] = $行[说明];
        $产品[created_at] = $行[created_at];
        $产品[的updated_at] = $行[的updated_at];        //推单一产品到最终响应数组
        array_push($响应[产品],$产品);
    }
    //成功
    $响应[成功] = 1;    //呼应JSON响应
    回声json_en code($响应);
}其他{
    //没有发现产品
    $响应[成功] = 0;
    $响应[消息] =没有找到产品;    //回声没有用户JSON
    回声json_en code($响应);
}
?>


解决方案

相反mashalling和自己和解组的对象,检查GSON图书馆,是由谷歌开发的。

函数库的使用:

希望它帮助。

I'm facing that problem when trying to retrieving data from database:

Error parsing data org.json.JSONException: Value <!DOCTYPE of type java.lang.String cannot be converted to JSONObject



public class AllProductsActivity 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://192.168.1.3/android_connect/get_all_products.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 TAG_NAME = "name";

    // products JSONArray
    JSONArray products = null;

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

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

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

        // Get listview
        ListView lv = getListView();

        // on seleting single product
        // launching Edit Product Screen
        lv.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {
                // getting values from selected ListItem
                String pid = ((TextView) view.findViewById(R.id.pid)).getText()
                        .toString();

                // Starting new intent
                Intent in = new Intent(getApplicationContext(),
                        EditProductActivity.class);
                // sending pid to next activity
                in.putExtra(TAG_PID, pid);

                // starting new activity and expecting some response back
                startActivityForResult(in, 100);
            }
        });

    }

    // 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(AllProductsActivity.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 name = c.getString(TAG_NAME);

                        // 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(TAG_NAME, name);

                        // adding HashList to ArrayList
                        productsList.add(map);
                    }
                } else {
                    // no products found
                    // Launch Add New product Activity
                    Intent i = new Intent(getApplicationContext(),
                            NewProductActivity.class);
                    // Closing all previous activities
                    i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                    startActivity(i);
                }
            } 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(
                            AllProductsActivity.this, productsList,
                            R.layout.list_item, new String[] { TAG_PID,
                                    TAG_NAME},
                            new int[] { R.id.pid, R.id.name });
                    // updating listview
                    setListAdapter(adapter);
                }
            });

        }

    }
}

The problem is excatly triggering when executing that line:

// getting JSON string from URL
    JSONObject json = jParser.makeHttpRequest(url_all_products, "GET", params);

What's going on with that code? I think that i'm not coding something wrong.Any help please?

PHP FILE:

<?php header('content-type: application/json; charset=utf-8');
/*
 * Following code will list all the products
 */

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


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

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

// get all products from products table
$result = mysql_query("SELECT * FROM products") or die(mysql_error());

// check for empty result
if (mysql_num_rows($result) > 0) {
    // looping through all results
    // products node
    $response["products"] = array();

    while ($row = mysql_fetch_array($result)) {
        // temp user array
        $product = array();
        $product["pid"] = $row["pid"];
        $product["name"] = $row["name"];
        $product["price"] = $row["price"];
        $product["description"] = $row["description"];
        $product["created_at"] = $row["created_at"];
        $product["updated_at"] = $row["updated_at"];



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

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

    // echo no users JSON
    echo json_encode($response);
}
?>
解决方案

Instead of mashalling and unmarshalling your objects by yourself, check the Gson Library, developed by Google.

http://code.google.com/p/google-gson/

Library Usage: https://sites.google.com/site/gson/gson-user-guide

Hope it helps.

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09-03 05:25