Question

我想在我的数据库中读取数据，然后在模拟器中显示它，因为我使用PHP脚本作为Web服务连接到我的Mysql数据库，但是我的程序在解析Json时抛出异常，这个例外：

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

我在互联网上做了一些研究，但我只是在没有解决方案的情况下发现了这个问题

如果有人能帮助我，我真的需要那个这是我的代码：

  <?php
  mysql_connect("localhost","root","root");
  mysql_select_db("bdVille");
  $sql=mysql_query("select * from tblVille where Nom_ville like'".$_REQUEST['ville']."%'");
  while($row=mysql_fetch_assoc($sql))
  $output[]=$row;
  print(json_encode($output));
  mysql_close();
  ?>

这是java代码：

package com.exemple.ville;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;

public class ville extends Activity {
TextView txt;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    LinearLayout rootLayout = new LinearLayout(getApplicationContext());  
    txt = new TextView(getApplicationContext());  
    rootLayout.addView(txt);  
    setContentView(rootLayout);  

    // D√©finir le texte et appeler la fonction de connexion.  
    txt.setText("Connexion..."); 
    // Appeler la m√©thode pour r√©cup√©rer les donn√©es JSON
    txt.setText(getServerData(strURL)); 
}

// Mettre l'adresse du script PHP
// Attention localhost ou 127.0.0.1 ne fonctionnent pas. Mettre l'adresse IP local.
public static final String strURL = "http://192.168.1.108/htdocs/ville.php";

private String getServerData(String returnString) {
    InputStream is = null;
    String result = "";
    // Envoyer la requ√™te au script PHP.
    // Script PHP : $sql=mysql_query("select * from tblVille where Nom_ville like '".$_REQUEST['ville']."%'");
    // $_REQUEST['ville'] sera remplac√© par L dans notre exemple.
    // Ce qui veut dire que la requ√™te enverra les villes commen√ßant par la lettre L
    ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
    nameValuePairs.add(new BasicNameValuePair("ville","L"));

    // Envoie de la commande http
    try{
        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost(strURL);
        httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
        HttpResponse response = httpclient.execute(httppost);
        HttpEntity entity = response.getEntity();
        is = entity.getContent();

    }catch(Exception e){
        Log.e("log_tag", "Error in http connection " + e.toString());
    }

    // Convertion de la requ√™te en string
    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();
        result=sb.toString();
    }catch(Exception e){
        Log.e("log_tag", "Error converting result " + e.toString());
    }
    // Parse les donn√©es JSON
    try{
        JSONArray jArray = new JSONArray(result);

        for(int i=0;i<jArray.length();i++){
            JSONObject json_data = jArray.getJSONObject(i);
            // Affichage ID_ville et Nom_ville dans le LogCat
            Log.i("log_tag","ID_ville: "+json_data.getInt("ID_ville")+", Nom_ville: "+json_data.getString("Nom_ville"));
            Toast.makeText(this, "ID_ville: "+json_data.getInt("ID_ville")+", Nom_ville: "+json_data.getString("Nom_ville"), Toast.LENGTH_SHORT).show();
            // R√©sultats de la requ√™te
            returnString += "\n\t" + jArray.getJSONObject(i); 
        }
    }catch(JSONException e){
        Log.e("log_tag", "Error parsing data " + e.toString());
    }
    return returnString; 
}

}

Answer 1

嘿，做出这些改变。

package com.Online.Test;

import java.io.IOException;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.widget.TextView;
import android.widget.Toast;

public class OnlineTestActivity extends Activity {
    /** Called when the activity is first created. */
    TextView resultView;
    HttpClient client;
    JSONObject json;
    String Dat;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        resultView = (TextView) findViewById(R.id.tvjson);
        client = new DefaultHttpClient();
        try {
            json = RedData();
        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

      Dat = json.toString();

        new Read().onPostExecute(Dat);
    }
    public JSONObject RedData() throws ClientProtocolException, IOException, JSONException {

        HttpPost httppost = new HttpPost("//link.php");     
        HttpResponse r = client.execute(httppost);

       // int status = r.getStatusLine().getStatusCode();

        //if (status == 200) {

            HttpEntity e = r.getEntity();
            String data = EntityUtils.toString(e);
            JSONArray jArray = new JSONArray(data);
            JSONObject last = jArray.getJSONObject(0); // 0 -> the last object
            return last;

       // } else {
         //   Toast.makeText(OnlineTestActivity.this, "error", Toast.LENGTH_LONG);
          //  return null;
        //}
    }


    public class Read extends AsyncTask<String, Integer, String> {

        @Override
        protected String doInBackground(String... arg0) {
            // TODO Auto-generated method stub
            try {
                json = RedData();
                //Toast.makeText(OnlineTestActivity.this, json.getString(arg0[0]), Toast.LENGTH_LONG);
                return json.getString(arg0[0]);

            } catch (ClientProtocolException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            return null;
        }

        @Override
        protected void onPostExecute(String data) {
            // TODO Auto-generated method stub
            resultView.setText(data);
        }
    }
}

Answer 2

我认为错误来自那一行：

JSONArray jArray = new JSONArray(result);

您正在尝试将无效的Json字符串转换为json数组。

Answer 3

事实上，你的json编码似乎没有正常工作，实际上是你给的JSON：

[
    {
        "ID_ville": "1",
        "Nom_ville": "Paris"
    },
    {
        "ID_ville": "2",
        "Nom_ville": "Marseille"
    },
    {
        "‌ID_ville": "3",
        "Nom_ville": "Lyon"
    },
    {
        "ID_ville": "4",
        "Nom_ville": "Toulouse"
    },
    {
        "ID_vi‌lle": "5",
        "Nom_ville": "Nice"
    },
    {
        "ID_ville": "6",
        "Nom_ville": "Nantes"
    },
    {
        "ID_ville": "7"‌,
        "Nom_ville": "Strasbourg"
    },
    {
        "ID_ville": "8",
        "Nom_ville": "Montpellier"
    },
    {
        "ID_ville"‌: "9",
        "Nom_ville": "Bordeaux"
    },
    {
        "ID_ville": "10",
        "Nom_ville": "Lille"
    }
]

尝试将它放在jsonlint.com中并且会给你错误，问题在于它是一个ZERO WIDTH JOINER字符，可能你可能想要开始只是回显静态json来检查这个。我的猜测，是你以某种方式复制粘贴这个角色。

测试这个角色的另一种方法是什么？，尝试复制粘贴这个{“ID_ville”：“9”，“Nom_ville”：“波尔多”}，在你的控制台中我会看到类似的东西

enter image description here

<强>解决方案

检查你的字符，编码并使用静态回声尝试响应，而不是转到数据库。

从android中读取mysql中的数据：ERROR：String无法转换为JSONArray

3 个答案: