java - 如何从 Android 读取 MYSQL 数据库？

Question

我想通过 PHP 从 MYSQL 数据库读取数据，从 Android 读取 JSON。 我一直在尝试许多不同的示例，但我的 Android 手机无法读取任何数据。 当我运行应用程序时，我的手机在加载应用程序后没有做任何事情:(

• MYSQL 数据库信息

数据库名称:PeopleData 表名:人 表有:id, name, sex, birtyear

• PHP 源代码:我测试了 index.php，结果是正确的。

-index.php

  <?php
  mysql_connect("127.0.0.1","root","");
  mysql_select_db("PeopleData");

  $q=mysql_query("SELECT * FROM people WHERE birthyear>1980");
  while($e=mysql_fetch_assoc($q))
        $output[]=$e;
  print(json_encode($output));
  mysql_close();
  ?>

• 用于获取数据库的Android java文件

    package com.json;
  
    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 JSON extends Activity {
  
     TextView resultView;
     HttpClient client;
     JSONObject json;
  
     // the year data to send
     @Override
     protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.json);
  
        resultView = (TextView) findViewById(R.id.tvjson);
        client = new DefaultHttpClient();
        new Read().execute("text");
     }
  
     public JSONObject RedData() throws ClientProtocolException,IOException,JSONException {
  
        HttpPost httppost = new HttpPost("http://127.0.0.1/series/database/index.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(JSON.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();
  
                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);
        }
      }
  
    }
  

• xml

    <TextView
        android:id="@+id/tvjson"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >
    </TextView>
  

• list

    <uses-sdk android:minSdkVersion="8" />
    <uses-permission android:name="android.permission.INTERNET"/>
    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:name=".JSON"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
  
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
  

• 控制台

    [2012-02-22 16:19:58 - json] Android Launch!
    [2012-02-22 16:19:58 - json] adb is running normally.
    [2012-02-22 16:19:58 - json] Performing com.json.JSON activity launch
    [2012-02-22 16:19:58 - json] Automatic Target Mode: Unable to detect device compatibility. Please select a target device.
    [2012-02-22 16:19:59 - json] Uploading json.apk onto device '01499EF80D00D009'
    [2012-02-22 16:19:59 - json] Installing json.apk...
    [2012-02-22 16:20:01 - json] Success!
    [2012-02-22 16:20:01 - json] Starting activity com.json.JSON on device 01499EF80D00D009
    [2012-02-22 16:20:02 - json] ActivityManager: Starting: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] cmp=com.json/.JSON }

• 设备

  什么都不做

我不知道我能做什么了。请任何人帮助我。 谢谢。

Answer 1

这应该可行

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);
        }
    }
}