Question

我试图在PHP Web服务的帮助下在Android中显示数据，但我认为我的代码存在一些问题，因此数据不会显示。我在这里给两个文件的代码

网络服务代码：

<?php
$dbhandle = mysql_connect($hostname, $username, $password,$datbase_name)
  or die("Unable to connect to
   MySQL");
$selected = mysql_select_db("code_Lessions",$dbhandle) 
or die("Could not select examples");
$final_data = array();
$query="SELECT * FROM LessionDetail"; 
if ($query_run = mysql_query($query)) 
    { 
        $i=0;
        while($query_row = mysql_fetch_assoc($query_run)) 
        { 
            $username = $query_row['LessionName']; 
            $password = $query_row ['CategoryName']; 
            $id = $query_row ['LessionId']; 
            //echo $username .'`s password is : '. $password.'<br>'; 
            $data = array('LessionId'=>$id , 'LessionName'=>$username ,'CategoryName'=>$password); 
            $final_data[$i]=$data;
            $i++;
            //print(json_encode($data)); 
            //print(json_encode($password)); 
        } 
        print(json_encode($final_data));
    }else{
     echo mysql_error(); 
    }
?>

档案：JSONExampleActivity.java

package com.json.php;

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

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.HashMap;

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.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;


public class JSONExampleActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost("http://code.guru99.com/android.php");
        TextView textView = (TextView)findViewById(R.id.textView1);
        try {
            HttpResponse response = httpclient.execute(httppost);
            String jsonResult = inputStreamToString(response.getEntity().getContent()).toString();
            JSONObject jObject = new JSONObject(jsonResult);
            JSONArray json = new JSONArray(jObject.getString(jsonResult));
            ArrayList<HashMap<String, String>> mylist = new ArrayList<HashMap<String, String>>();
            HashMap<String, String> map = new HashMap<String, String>();
            for(int i=0;i<json.length();i++){       
                /*map = new HashMap<String, String>();
                                JSONObject e = json.getJSONObject(i);
                                map.put("id",  String.valueOf(i));
                                map.put("name", "lname" + e.getString("name"));
                                map.put("Category", "Category: " +  e.getString("Category"));
                                mylist.add(map); 
                              System.out.println("The values are: " + map.values());*/
                JSONObject oneObject = json.getJSONObject(i);
                // Pulling items from the array
                String id = oneObject.getString("id");
                String name = oneObject.getString("name");
                String category = oneObject.getString("category");
                textView.setText(id + "-" + name + "-" + category);
                            }
        } 
        catch (JSONException e) {
            e.printStackTrace();
        } 
        catch (ClientProtocolException e) {
            e.printStackTrace();
        } 
        catch (IOException e) {
            e.printStackTrace();
        }


       }
    private JSONObject JSONObject(String jsonResult) {
        // TODO Auto-generated method stub
        return null;
    }
    private StringBuilder inputStreamToString(InputStream is) {
        String rLine = "";
        StringBuilder answer = new StringBuilder();
        BufferedReader rd = new BufferedReader(new InputStreamReader(is));

        try {
         while ((rLine = rd.readLine()) != null) {
          answer.append(rLine);
           }
        }

        catch (IOException e) {
            e.printStackTrace();
         }
        return answer;
       }
}

我的数据库中有两条记录，我想显示该表中的整个数据，但没有显示任何内容。

Answer 1

这不是一个完整的答案，但您可以使用以下内容来帮助调试代码。

HttpResponse response = httpclient.execute(httppost);
        String jsonResult = inputStreamToString(response.getEntity().getContent()).toString();
Log.d("JSONDebug" , jsonResult);

这将显示您在日志记录中收到的输入。所以从那里可以更容易地确定json是否处于wring格式或者读者的输入是否完全没有，我认为更可能是这种情况，因为从你的帖子看起来你似乎没有得到jsonParser错误

借助Web服务在Android中显示数据

1 个答案: