Json 解析错误 - java.lang.String 类型的值 <br 无法转换为 JSONObject

Question

我一直在尝试将我的 android 应用程序连接到我的本地 Web 服务器，但该应用程序每次尝试解析数据时都会崩溃。我不知道为什么会出现'

JSONParser 类

public class JSONParser {

static InputStream is = null;
static JSONObject jObj = null;
static String json = "";

// constructor
public JSONParser() {

}

// function get json from url
// by making HTTP POST or GET mehtod
public JSONObject makeHttpRequest(String url, String method,
        List<NameValuePair> params) {

    // Making HTTP request
    try {

        // check for request method
        if(method == "POST"){
            // request method is POST
            // defaultHttpClient
            DefaultHttpClient httpClient = new DefaultHttpClient();
            HttpPost httpPost = new HttpPost(url);
            httpPost.setEntity(new UrlEncodedFormEntity(params));

            HttpResponse httpResponse = httpClient.execute(httpPost);
            HttpEntity httpEntity = httpResponse.getEntity();
            is = httpEntity.getContent();

        }else if(method == "GET"){
            // request method is GET
            DefaultHttpClient httpClient = new DefaultHttpClient();
            String paramString = URLEncodedUtils.format(params, "utf-8");
            url += "?" + paramString;
            HttpGet httpGet = new HttpGet(url);

            HttpResponse httpResponse = httpClient.execute(httpGet);
            HttpEntity httpEntity = httpResponse.getEntity();
            is = httpEntity.getContent();
        }           


    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

    try {
        BufferedReader reader = new BufferedReader(new InputStreamReader(
                is, "iso-8859-1"), 8);
        StringBuilder sb = new StringBuilder();
        String line = null;
        while ((line = reader.readLine()) != null) {
            sb.append(line + "\n");
        }
        is.close();
        json = sb.toString();
        json = json.replaceAll("db_connect.php", "");
    } catch (Exception e) {
        Log.e("Buffer Error", "Error converting result " + e.toString());
    }

    // try parse the string to a JSON object
    try {
        jObj = new JSONObject(json);
    } catch (JSONException e) {
        Log.e("JSON Parser", "Error parsing data " + e.toString());
    }

    // return JSON String
    return jObj;

}

新产品活动

public class NewProductActivity extends Activity {

// Progress Dialog
private ProgressDialog pDialog;

JSONParser jsonParser = new JSONParser();
EditText inputName;
EditText inputPrice;
EditText inputDesc;

// url to create new product
private static String url_create_product = "http://192.168.1.150/android_connect/create_product.php";

// JSON Node names
private static final String TAG_SUCCESS = "success";

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

    // Edit Text
    inputName = (EditText) findViewById(R.id.inputName);
    inputPrice = (EditText) findViewById(R.id.inputPrice);
    inputDesc = (EditText) findViewById(R.id.inputDesc);

    // Create button
    Button btnCreateProduct = (Button) findViewById(R.id.btnCreateProduct);

    // button click event
    btnCreateProduct.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View view) {
            // creating new product in background thread
            new CreateNewProduct().execute();
        }
    });
}

/**
 * Background Async Task to Create new product
 * */
class CreateNewProduct extends AsyncTask<String, String, String> {

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

    /**
     * Creating product
     * */
    protected String doInBackground(String... args) {
        String name = inputName.getText().toString();
        String price = inputPrice.getText().toString();
        String description = inputDesc.getText().toString();

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

        // 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(), AllProductsActivity.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();
    }

}

create_product.php

<?php 
$response = array();

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

$name = $_POST['name'];
$price = $_POST['price'];
$description = $_POST['description'];

require_once '/db_connect.php';

$db = new DB_CONNECT();

$result = mysql_query("INSERT INTO products(name, price, description) VALUES('$name', '$price', '$description')");

// check if row inserted or not
if ($result) {
    $response["success"] = 1;
    $response["message"] = "Product successfully created.";

    echo json_encode($response);
} else {
    $response["success"] = 0;
    $response["message"] = "Oops! An error occurred.";

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

echo json_encode($response);
}
?>

编辑：添加了 create_product 脚本

任何帮助将不胜感激。

Answer 1

你好我有同样的问题，几乎相同的代码，解决方案很简单，大多数时候错误隐藏在 php 代码中，当解析开始时，它会在 JSON 中抛出 php 错误，它不能转换它。 错误就像“第 15 行中的 br 错误”，然后是 json 数据。

所以：只有你需要用你的 LogCat 跟随代码：

Log.d("No here error!", "Im inside if function");

要跟踪问题开始的确切位置，但最重要的是进入 JSONParser 类并将此行添加到异常捕获中并执行以下操作：

 try {
    jObj = new JSONObject(json);
} catch (JSONException e) {
    //This line is what u need to add
    Log.d("Whats wrong?", json.toString());
    Log.e("JSON Parser", "Error parsing data " + e.toString());
}

运行应用程序后，它仍然会出现错误，但在 logcat 中，它会描述你从 JSON 获得的数据，请明智地使用它！