php - 如何将Android与PHP和MySQL连接？

Question

这个问题已经有答案了:

How can I fix 'android.os.NetworkOnMainThreadException'? (65 个回答)

已关闭 9 年前。

我正在尝试使用 PHP 和 MySQL 连接 Android 系统来创建一个简单的登录 Activity 。我正在使用在 4.2 Android 版本上运行的 genymotion 模拟器。

我在代码中使用线程使其在后台运行，并使用 JSON 顺利地取回数据。

但问题是系统崩溃并强行关闭。如果有人可以帮助我，我将不胜感激。

日志猫

02-02 21:29:46.260: E/AndroidRuntime(1363): FATAL EXCEPTION: main
02-02 21:29:46.260: E/AndroidRuntime(1363): android.os.NetworkOnMainThreadException
02-02 21:29:46.260: E/AndroidRuntime(1363):     at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1133)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:84)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at libcore.io.IoBridge.connectErrno(IoBridge.java:127)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at libcore.io.IoBridge.connect(IoBridge.java:112)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:459)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at java.net.Socket.connect(Socket.java:842)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:119)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:144)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at pack.coderzheaven.JSONParser.makeHttpRequest(JSONParser.java:65)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at pack.coderzheaven.AndroidPHPConnectionDemo$CheckLogin$1.run(AndroidPHPConnectionDemo.java:118)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at android.os.Handler.handleCallback(Handler.java:730)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at android.os.Handler.dispatchMessage(Handler.java:92)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at android.os.Looper.loop(Looper.java:137)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at android.app.ActivityThread.main(ActivityThread.java:5103)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at java.lang.reflect.Method.invokeNative(Native Method)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at java.lang.reflect.Method.invoke(Method.java:525)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
02-02 21:29:46.260: E/AndroidRuntime(1363):     at dalvik.system.NativeStart.main(Native Method)

JSONParser.java

package pack.coderzheaven;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.List;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;

import android.util.Log;

public class JSONParser {

    static InputStream is = null;
    static JSONObject jObj = null;
    static String json = "";

    // constructor
    public JSONParser() {

    }

    // function get json from url
    // by making HTTP POST or GET mehtod
    public JSONObject makeHttpRequest(String url, String method,
            List<NameValuePair> params) {

        // Making HTTP request
        try {

            // check for request method
        /*
            if(method == "POST"){
                // request method is POST
                // defaultHttpClient
                DefaultHttpClient httpClient = new DefaultHttpClient();
                HttpPost httpPost = new HttpPost(url);
                httpPost.setEntity(new UrlEncodedFormEntity(params));

                HttpResponse httpResponse = httpClient.execute(httpPost);
                HttpEntity httpEntity = httpResponse.getEntity();
                is = httpEntity.getContent();

            }
            */
             if(method == "GET"){
                // request method is GET
                DefaultHttpClient httpClient = new DefaultHttpClient();
                String paramString = URLEncodedUtils.format(params, "utf-8");
                url += "?" + paramString;
                HttpGet httpGet = new HttpGet(url);

                HttpResponse httpResponse = httpClient.execute(httpGet);
                HttpEntity httpEntity = httpResponse.getEntity();
                is = httpEntity.getContent();
            }           


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

        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();
            json = sb.toString();
        } catch (Exception e) {
            Log.e("Buffer Error", "Error converting result " + e.toString());
        }

        // try parse the string to a JSON object
        try {
            jObj = new JSONObject(json);
        } catch (JSONException e) {
            Log.e("JSON Parser", "Error parsing data " + e.toString());
        }

        // return JSON String
        return jObj;

    }
}

AndroidPHPConnection演示

package pack.coderzheaven;

import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.Activity;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class AndroidPHPConnectionDemo extends Activity {
    Button b;
    EditText et, pass;
    String Username, Password;
    TextView tv;
    HttpPost httppost;
    StringBuffer buffer;
    HttpResponse response;
    HttpClient httpclient;
    List<NameValuePair> nameValuePairs;

    String pid;

    // Progress Dialog
    private ProgressDialog pDialog;

    // JSON parser class
    JSONParser jsonParser = new JSONParser();


    private static final String url_check_login = "http://10.0.3.2/check.php";

    // JSON Node names
    private static final String TAG_SUCCESS = "success";
    private static final String TAG_PERSON = "person";
    private static final String TAG_PID = "pid";
    private static final String TAG_NAME = "username";
    private static final String TAG_pass = "password";

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        b = (Button) findViewById(R.id.Button01);
        et = (EditText) findViewById(R.id.username);
        pass = (EditText) findViewById(R.id.password);
        tv = (TextView) findViewById(R.id.tv);

        b.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                // login();

                // Getting complete person details in background thread
                new CheckLogin().execute();

            }
        });
    }

    /**
     * Background Async Task to Get complete person details
     * */
    class CheckLogin extends AsyncTask<String, String, String> {

        /**
         * Before starting background thread Show Progress Dialog
         * */
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(AndroidPHPConnectionDemo.this);
            pDialog.setMessage("Loading person details. Please wait...");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(true);
            pDialog.show();
        }

        /**
         * Getting person details in background thread
         * */

        @Override
        protected String doInBackground(String... arg0) {
            // TODO Auto-generated method stub
            // updating UI from Background Thread
            runOnUiThread(new Runnable() {
                public void run() {
                    // Check for success tag
                    int success;
                    try {
                        // Building Parameters
                        List<NameValuePair> params = new ArrayList<NameValuePair>();
                        params.add(new BasicNameValuePair("pid", pid));

                        // getting person details by making HTTP request
                        // Note that person details url will use GET request
                        JSONObject json = jsonParser.makeHttpRequest(
                                url_check_login, "GET", params);

                        // check your log for json response
                        Log.d("Single person Details", json.toString());

                        // json success tag
                        success = json.getInt(TAG_SUCCESS);
                        if (success == 1) {
                            // successfully received person details
                            JSONArray productObj = json
                                    .getJSONArray(TAG_PERSON); // JSON Array

                            // get first product object from JSON Array
                            JSONObject person = productObj.getJSONObject(0);

                            et.setText(person.getString(TAG_NAME));
                            pass.setText(person.getString(TAG_pass));

                            Log.e("success in login", "SUCCESS IN LOGIN");

                        }

                        else {
                            // product with pid not found
                        }
                    } catch (JSONException e) {
                        e.printStackTrace();
                    }
                }
            });

            return null;
        }

        /**
         * After completing background task Dismiss the progress dialog
         * **/
        protected void onPostExecute(String file_url) {
            // dismiss the dialog once got all details
            pDialog.dismiss();
        }
    }

检查.php

<?php

require_once('db_config.php'); 


// array for JSON response
$response = array();


//if(isset($_GET['Username'])and isset($_POST['Password'])){

  if(isset($_GET['pid'])){
//   $username = $_POST['Username'];
//   $password = $_POST['Password'];

     $pid = $_GET['pid'];   

//   $query_search = "select username, password from members where username = '".$username."' AND password = '".$password. "'";

     $query_search = "select from members where pid = '".$pid."'";   

     $query_exec = mysql_query($query_search) or die(mysql_error());

   if (mysql_num_rows($query_exec) > 0) 
   {
        $result = mysql_fetch_array($query_exec);

        $person = array();
        $person['username']=$result[username];
        $person['password']=$result['password'];

   // success
        $response["success"] = 1;

   // user node
        $response["person"] = array();

        array_push($response["person"], $person);

   // echoing JSON response
        echo json_encode($response);

    }
    else
    {
   // no user found
            $response["success"] = 0;
            $response["message"] = "No User found";

   // echo no users JSON
           echo json_encode($response);
    }
}
else 
{
    // required field is missing
    $response["success"] = 0;
    $response["message"] = "Required field(s) is missing";

    // echoing JSON response
    echo json_encode($response);
}    
?>

Answer 1

问题出在 AsyncTask 内的 runOnUiThread 上。您收到异常是因为您占用 UI 线程的时间太长。使用 AsyncTask 是正确的做法，但是您从其中调用 runOnUiThread，这是没有意义的，因为这样它就不再是异步的。

1. 从其中删除 runOnUiThread 部分doInBackground()。
2. 保留您想要在屏幕上显示的值作为异步任务的成员或作为结果模板参数。
3. 将 setText 调用放在 postExecute 中，因为它是在 UI 上运行的线程。

类似这样的事情:

/**
 * Background Async Task to Get complete person details
 * */
class CheckLogin extends AsyncTask<String, String, String> {

    JSONArray productObj;

    /**
     * Before starting background thread Show Progress Dialog
     * */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(AndroidPHPConnectionDemo.this);
        pDialog.setMessage("Loading person details. Please wait...");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(true);
        pDialog.show();
    }

    /**
     * Getting person details in background thread
     * */

    @Override
    protected String doInBackground(String... arg0) {
        // TODO Auto-generated method stub

                int success;
                try {
                    // Building Parameters
                    List<NameValuePair> params = new ArrayList<NameValuePair>();
                    params.add(new BasicNameValuePair("pid", pid));

                    // getting person details by making HTTP request
                    // Note that person details url will use GET request
                    JSONObject json = jsonParser.makeHttpRequest(
                            url_check_login, "GET", params);

                    // check your log for json response
                    Log.d("Single person Details", json.toString());

                    // json success tag
                    success = json.getInt(TAG_SUCCESS);
                    if (success == 1) {
                        // successfully received person details
                        productObj = json
                                .getJSONArray(TAG_PERSON); // JSON Array

                    }

                    else {
                        // product with pid not found
                    }
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }

        return null;
    }

    /**
     * After completing background task Dismiss the progress dialog
     * **/
    protected void onPostExecute(String file_url) {
        // dismiss the dialog once got all details


        if ( productObj != null ) {
            // get first product object from JSON Array
            JSONObject person = productObj.getJSONObject(0);

            et.setText(person.getString(TAG_NAME));
            pass.setText(person.getString(TAG_pass));

            Log.e("success in login", "SUCCESS IN LOGIN");
        }

        pDialog.dismiss();
    }
}