java - android studio json数据解析错误

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给出错误 In EXCEPTION .... json data parsing error in catch in postexecute method 请帮助如何解决。当数据输入其中时，它开始顺利工作，但是当发送数据时，它显示 json 数据解析错误

/**
 * Created by Mian on 2/28/2016.
 */
import android.content.Context;
import android.os.AsyncTask;
import android.widget.Toast;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
public class SignupActivity extends AsyncTask<String, Void, String> {
    private Context context;
    public SignupActivity(Context context) {
        this.context = context;
    }

    protected void onPreExecute() {
    }
    @Override
    protected String doInBackground(String... arg0) {
        String fullName = arg0[0];
        String userName = arg0[1];
        String passWord = arg0[2];
        String phoneNumber = arg0[3];
        String emailAddress = arg0[4];
        String link;
        String data;
        BufferedReader bufferedReader;
        String result;
        try {
            data = "?fullname=" + URLEncoder.encode(fullName, "UTF-8");
            data += "&username=" + URLEncoder.encode(userName, "UTF-8");
            data += "&password=" + URLEncoder.encode(passWord, "UTF-8");
            data += "&phonenumber=" + URLEncoder.encode(phoneNumber, "UTF-8");
            data += "&emailaddress=" + URLEncoder.encode(emailAddress, "UTF-8");
            link = "http://livethuglife.com/signup.php" + data;
            URL url = new URL(link);
            HttpURLConnection con = (HttpURLConnection) url.openConnection();
            bufferedReader = new BufferedReader(new InputStreamReader(con.getInputStream()));
            result = bufferedReader.readLine();
            return result;
        } catch (Exception e) {
            return new String("Exception: " + e.getMessage());
        }
    }
    @Override
    protected void onPostExecute(String result) {
        String jsonStr = result.toString();
        if (jsonStr != null) {
            try {
                JSONObject jsonObj = new JSONObject(jsonStr);
                String query_result = jsonObj.getString("query_result");
                if (query_result.equals("SUCCESS")) {
                    Toast.makeText(context, "Data inserted successfully. Signup successfull.", Toast.LENGTH_SHORT).show();
                } else if (query_result.equals("FAILURE")) {
                    Toast.makeText(context, "Data could not be inserted. Signup failed.", Toast.LENGTH_SHORT).show();
                } else {
                    Toast.makeText(context, "Couldn't connect to remote database.", Toast.LENGTH_SHORT).show();
                }
            } catch (JSONException e) {
                e.printStackTrace();
                Toast.makeText(context, "Error parsing JSON data.", Toast.LENGTH_SHORT).show();
            }
        } else {
            Toast.makeText(context, "Couldn't get any JSON data.", Toast.LENGTH_SHORT).show();
        }
    }
}

Answer 1

最好根据您已发布到服务器的表单使用类。

1. 一个简单的Java类，带有多个字段，需要将完整的表单数据传送到服务器。就像我定义为 SignUp 类一样。

2. 然后创建该Class SignUp的对象，将对象填充为您所对应的值想要发布到服务器。

3. 现在使用 Google gson.jar 将 object 更改为 JSON(您可以通过在互联网上搜索来下载)

   A Simple Example I have shown to you..

A Simple POJO Class SignUP

Class SignUP{
   private String fullname;
   private String username;
   private String passoword;  // Define Number of Variable as per your Need
   private String phonenumber;
   private String emailaddress;

       //Getter and Setters Method.
}

现在实例化您的类并尝试 Google GSON 库 jar 将其解析为 JSON 对象。

A Simple Logic to Convert Object of Class SignUP to JSON .

protected String doInBackground(String... arg0) {
    String fullName = arg0[0];
    String userName = arg0[1];
    String passWord = arg0[2];
    String phoneNumber = arg0[3];
    String emailAddress = arg0[4];

    SignUP obj = new SignUP();
    obj.setFullName(URLEncoder.encode(fullName, "UTF-8"));
    obj.setUserName(URLEncoder.encode(userName, "UTF-8"));
    obj.setPassword(URLEncoder.encode(passWord, "UTF-8"););
    obj.setPhoneNumber(URLEncoder.encode(phoneNumber,"UTF-8"););
    obj.setEmailAddress(URLEncoder.encode(emailAddress, "UTF-8"););
     
    Gson gson = new Gson();
     
    System.out.println(gson.toJson(obj));
    }

输出:

{
  "fullName":"FullName",
  "username":"Lokesh",
  "password":"Gupta",
  "phonenumber":"73479273423",
  "emailaddress":"abc @abc.com"
}

您也可以尝试How to Convert Java Object to JSON Using Google GSON API