Question

我正在尝试通过AsyncTask连接到我服务器上的外部数据库，但Eclipse在日志中显示错误 -

以下是我正在使用的代码 -

MainActivity.java：

package com.deltware.newco;

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

import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity {

    TextView res;
    Button btn1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        this.res = (TextView) this.findViewById(R.id.textView1);
        this.btn1 = (Button) this.findViewById(R.id.button1);

        this.btn1.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View arg0) {
                new getAllUsersTask().execute(new Connector());
            }
        });
    }

    public void setTextToView(JSONArray json){
        String s= "";

        for(int i = 0; i<json.length(); i++){
            JSONObject jo = null;
            try{
                jo = json.getJSONObject(i);
                s += "Name: " + jo.getString("name") +
                    "Email: " + jo.getString("email");
            }catch(JSONException e){
                e.printStackTrace();
            }
        }
        this.res.setText(s);
    }

    private class getAllUsersTask extends AsyncTask<Connector, Long,JSONArray>{

        @Override
        protected JSONArray doInBackground(Connector... param) {
            return param[0].getAllUsers();
        }

        @Override
        protected void onPostExecute(JSONArray result) {
            setTextToView(result);
        }

    }

}

Connector.java：

package com.deltware.newco;

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.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.impl.conn.DefaultClientConnection;
import org.apache.http.protocol.DefaultedHttpContext;
import org.apache.http.util.EntityUtils;
import org.json.JSONArray;
import org.json.JSONException;

import android.util.Log;

public class Connector {

    public JSONArray getAllUsers(){
        String url = "url to the location of my php file";

        HttpEntity httpEntity = null;

        try{

            DefaultHttpClient httpClient = new DefaultHttpClient();
            HttpGet httpget = new HttpGet(url);

            HttpResponse httpResponse = httpClient.execute(httpget);
            httpEntity = httpResponse.getEntity();

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

        JSONArray json = null;
        if(httpEntity == null){
            try{
                String entityResponse = EntityUtils.toString(httpEntity);
                Log.e("Entity Response:",entityResponse);
                json = new JSONArray(entityResponse);
            }catch(JSONException e){
                e.printStackTrace();
            }catch(IOException e){
                e.printStackTrace();
            }
        }

        return json;
    }

}

PHP文件：

$query = mysqli_query($db, "SELECT name, email, gender FROM users");
    while($row = mysqli_fetch_assoc($query)){
        $ouput[] = $row;
    }
    echo json_encode($ouput);

我正在使用Eclipse和Android 4.4 KitKat。

连接到在线数据库时出错

0 个答案: