Android，从应用程序发送字符串到网络服务器

Question

我想做一个应用程序，我应该从应用程序发送数据到Web服务器。 到目前为止，我一直在搜索，但无法找到一个工作的例子，我发现一些使用asynctask哪些不起作用，所以任何帮助表示赞赏！

Answer 1

试试下面的代码： -

import java.io.BufferedReader; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.InputStreamReader; 
import org.apache.http.HttpResponse; 
import org.apache.http.client.HttpClient; 
import org.apache.http.client.methods.HttpPost; 
import org.apache.http.entity.StringEntity; 
import org.apache.http.impl.client.DefaultHttpClient; 
import org.json.JSONObject; 
import android.net.ConnectivityManager; 
import android.net.NetworkInfo; 
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; 
import android.widget.Toast; 
import android.app.Activity; 
import com.hmkcode.android.vo.Person; 

public class MainActivity extends Activity implements OnClickListener { 

    TextView tvIsConnected; 
    EditText etName,etCountry,etTwitter; 
    Button btnPost; 

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

     // get reference to the views 
     tvIsConnected = (TextView) findViewById(R.id.tvIsConnected); 
     etName = (EditText) findViewById(R.id.etName); 
     etCountry = (EditText) findViewById(R.id.etCountry); 
     etTwitter = (EditText) findViewById(R.id.etTwitter); 
     btnPost = (Button) findViewById(R.id.btnPost); 

     // check if you are connected or not 
     if(isConnected()){ 
      tvIsConnected.setBackgroundColor(0xFF00CC00); 
      tvIsConnected.setText("You are conncted"); 
     } 
     else{ 
      tvIsConnected.setText("You are NOT conncted"); 
     } 

     // add click listener to Button "POST" 
     btnPost.setOnClickListener(this); 

    } 

    public static String POST(String url, Person person){ 
     InputStream inputStream = null; 
     String result = ""; 
     try { 

      // 1. create HttpClient 
      HttpClient httpclient = new DefaultHttpClient(); 

      // 2. make POST request to the given URL 
      HttpPost httpPost = new HttpPost(url); 

      String json = ""; 

      // 3. build jsonObject 
      JSONObject jsonObject = new JSONObject(); 
      jsonObject.accumulate("name", person.getName()); 
      jsonObject.accumulate("country", person.getCountry()); 
      jsonObject.accumulate("twitter", person.getTwitter()); 

      // 4. convert JSONObject to JSON to String 
      json = jsonObject.toString(); 

      // ** Alternative way to convert Person object to JSON string usin Jackson Lib 
      // ObjectMapper mapper = new ObjectMapper(); 
      // json = mapper.writeValueAsString(person); 

      // 5. set json to StringEntity 
      StringEntity se = new StringEntity(json); 

      // 6. set httpPost Entity 
      httpPost.setEntity(se); 

      // 7. Set some headers to inform server about the type of the content 
      httpPost.setHeader("Accept", "application/json"); 
      httpPost.setHeader("Content-type", "application/json"); 

      // 8. Execute POST request to the given URL 
      HttpResponse httpResponse = httpclient.execute(httpPost); 

      // 9. receive response as inputStream 
      inputStream = httpResponse.getEntity().getContent(); 

      // 10. convert inputstream to string 
      if(inputStream != null) 
       result = convertInputStreamToString(inputStream); 
      else 
       result = "Did not work!"; 

     } catch (Exception e) { 
      Log.d("InputStream", e.getLocalizedMessage()); 
     } 

     // 11. return result 
     return result; 
    } 

    public boolean isConnected(){ 
     ConnectivityManager connMgr = (ConnectivityManager) getSystemService(Activity.CONNECTIVITY_SERVICE); 
      NetworkInfo networkInfo = connMgr.getActiveNetworkInfo(); 
      if (networkInfo != null && networkInfo.isConnected()) 
       return true; 
      else 
       return false;  
    } 
    @Override 
    public void onClick(View view) { 

     switch(view.getId()){ 
      case R.id.btnPost: 
       if(!validate()) 
        Toast.makeText(getBaseContext(), "Enter some data!", Toast.LENGTH_LONG).show(); 
       // call AsynTask to perform network operation on separate thread 
       new HttpAsyncTask().execute("http://hmkcode.appspot.com/jsonservlet"); 
      break; 
     } 

    } 
    private class HttpAsyncTask extends AsyncTask<String, Void, String> { 
     @Override 
     protected String doInBackground(String... urls) { 

      person = new Person(); 
      person.setName(etName.getText().toString()); 
      person.setCountry(etCountry.getText().toString()); 
      person.setTwitter(etTwitter.getText().toString()); 

      return POST(urls[0],person); 
     } 
     // onPostExecute displays the results of the AsyncTask. 
     @Override 
     protected void onPostExecute(String result) { 
      Toast.makeText(getBaseContext(), "Data Sent!", Toast.LENGTH_LONG).show(); 
     } 
    } 

    private boolean validate(){ 
     if(etName.getText().toString().trim().equals("")) 
      return false; 
     else if(etCountry.getText().toString().trim().equals("")) 
      return false; 
     else if(etTwitter.getText().toString().trim().equals("")) 
      return false; 
     else 
      return true;  
    } 
    private static String convertInputStreamToString(InputStream inputStream) throws IOException{ 
     BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream)); 
     String line = ""; 
     String result = ""; 
     while((line = bufferedReader.readLine()) != null) 
      result += line; 

     inputStream.close(); 
     return result; 

    } 
} 

见下面的链接了解更多信息： -

http://hmkcode.com/android-send-json-data-to-server/

http://androidexample.com/How_To_Make_HTTP_POST_Request_To_Server_-_Android_Example/index.php?view=article_discription&aid=64&aaid=89

Answer 2

试试这个，

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.ResponseHandler; 
import org.apache.http.client.entity.UrlEncodedFormEntity; 
import org.apache.http.client.methods.HttpPost; 
import org.apache.http.impl.client.BasicResponseHandler; 
import org.apache.http.impl.client.DefaultHttpClient; 
import org.apache.http.message.BasicNameValuePair; 

import android.app.Activity; 
import android.app.AlertDialog; 
import android.app.ProgressDialog; 
import android.content.DialogInterface; 
import android.content.Intent; 
import android.content.SharedPreferences; 
import android.content.SharedPreferences.Editor; 
import android.os.AsyncTask; 
import android.os.Bundle; 
import android.preference.PreferenceManager; 
import android.view.Menu; 
import android.view.MenuInflater; 
import android.view.MenuItem; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.Button; 
import android.widget.CheckBox; 
import android.widget.EditText; 
import android.widget.Toast; 

public class AdminLogin extends Activity { 

    EditText adminUN, adminPass; 
    CheckBox cb; 
    Button loginBtn; 
    HttpPost httppost; 
    StringBuffer buffer; 
    HttpResponse response; 
    HttpClient httpclient; 
    List<NameValuePair> nameValuePairs; 

    // Your IP address or your website complete address 
    String adminLoginURL = "http://192.168.1.1/admin_login.php"; 
    ProgressDialog dialog = null; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     // TODO Auto-generated method stub 
     super.onCreate(savedInstanceState); 

     setContentView(R.layout.admin_login); 

     loginBtn = (Button) findViewById(R.id.adminLogin); 
     adminUN = (EditText) findViewById(R.id.adminUName); 
     adminPass = (EditText) findViewById(R.id.adminPass); 

     loginBtn.setOnClickListener(new OnClickListener() { 
      @Override 
      public void onClick(View v) { 

       new Admin_Login().execute(); 

      } 
     }); 
    } 

    class Admin_Login extends AsyncTask<String, String, String> { 
     @Override 
     protected void onPreExecute() { 
      super.onPreExecute(); 
      dialog = new ProgressDialog(AdminLogin.this); 
      dialog.setMessage("Please Wait..!"); 
      dialog.setIndeterminate(false); 
      dialog.setCancelable(true); 
      dialog.show(); 
     } 

     protected String doInBackground(String... params) { 

      new Thread(new Runnable() { 
       public void run() { 
        login(); 
       } 
      }).start(); 

      return null; 
     } 

     protected void onPostExecute(String file_url) { 
      // dismiss the dialog once got all details 
      dialog.dismiss(); 
     } 

    } 

    void login() { 
     try { 

      httpclient = new DefaultHttpClient(); 
      httppost = new HttpPost(adminLoginURL); 

      // add your data 
      nameValuePairs = new ArrayList<NameValuePair>(2); 
      nameValuePairs.add(new BasicNameValuePair("username", adminUN 
        .getText().toString().trim())); 
      nameValuePairs.add(new BasicNameValuePair("password", adminPass 
        .getText().toString().trim())); 
      httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs)); 
      // Execute HTTP Post Request 
      response = httpclient.execute(httppost); 

      ResponseHandler<String> responseHandler = new BasicResponseHandler(); 
      final String response = httpclient.execute(httppost, 
        responseHandler); 

      boolean matches = response.startsWith("User Found"); 
      if (matches) { 
       // Do something start an Activity or do anything you wanted 
       } 
      } else { 
       showAlert(); 
      } 

     } catch (Exception e) { 
      dialog.dismiss(); 
      System.out.println("Exception : " + e.getMessage()); 
     } 
    } 

    public void showAlert() { 
     AdminLogin.this.runOnUiThread(new Runnable() { 
      public void run() { 
       AlertDialog.Builder builder = new AlertDialog.Builder(
         AdminLogin.this); 
       builder.setTitle("Login Error."); 
       builder.setMessage("User not Found.") 
         .setCancelable(false) 
         .setPositiveButton("OK", 
           new DialogInterface.OnClickListener() { 
            public void onClick(DialogInterface dialog, 
              int id) { 
            } 
           }); 
       AlertDialog alert = builder.create(); 
       alert.show(); 
      } 
     }); 

    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu items for use in the action bar 
     MenuInflater inflater = getMenuInflater(); 
     inflater.inflate(R.menu.main_exit, menu); 
     return super.onCreateOptionsMenu(menu); 
    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     // Handle presses on the action bar items 
     switch (item.getItemId()) { 
     case R.id.action_exit: 
      finish(); 
      return true; 
     default: 
      return super.onOptionsItemSelected(item); 
     } 
    } 
} 

创建一个.xml文件来获取用户名，密码和登录按钮

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:background="@drawable/ic_wall" 
    android:gravity="center_horizontal" 
    android:orientation="vertical" > 

    <EditText 
     android:id="@+id/adminUName" 
     android:layout_width="250dp" 
     android:layout_height="wrap_content" 
     android:layout_marginTop="50dip" 
     android:hint="Username" 
     android:singleLine="true" /> 

    <requestFocus /> 

    <EditText 
     android:id="@+id/adminPass" 
     android:layout_width="250dp" 
     android:layout_height="wrap_content" 
     android:layout_marginTop="10dip" 
     android:ems="10" 
     android:hint="Password" 
     android:inputType="textPassword" 
     android:singleLine="true" /> 

    <Button 
     android:id="@+id/adminLogin" 
     android:layout_width="150dp" 
     android:layout_height="wrap_content" 
     android:layout_gravity="center_horizontal" 
     android:layout_marginTop="20dip" 
     android:text="Login" 
     android:textColor="#0b84aa" /> 

</LinearLayout> 

你必须有phpMyAdmin尝试这种在本地系统中，如果你有托管服务器，然后尝试部分使用下面的PHP代码并运行它。

adminLogin.php 

<?php 
$hostname_localhost =""; 
$database_localhost =""; 
$username_localhost =""; 
$password_localhost =""; 
# Make sure above fields are filled with your config values (must) 
$localhost = mysql_connect($hostname_localhost,$username_localhost,$password_localhost) 
or 
trigger_error(mysql_error(),E_USER_ERROR); 

mysql_select_db($database_localhost, $localhost); 


if (empty($_POST['username'])) { 
     echo "Please Enter a name"; 
    } else { 
     $username = $_POST['username']; 
    } 
    if (empty($_POST['password'])) { 
    echo "Please Enter Your Password "; 
    } else { 
     $password = SHA1($_POST['password']); 
    } 



$query_search = "select * from adminregister where username = '".$username."' AND password = '".$password."'"; 
$query_exec = mysql_query($query_search) or die(mysql_error()); 
$rows = mysql_num_rows($query_exec); 
//echo $rows; 
if($rows == 0) { 
echo "\nNo Such User Found"; 
} 
else { 

    echo "User Found"; 
} 
mysql_close(); 
?> 

注意：您需要在MySQL中创建指定的数据库和表饲料和检索数据

如果有任何错误，请发表评论。