Android，从应用程序发送字符串到网络服务器

[weixin_38078374]

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！

[weixin_38087646]

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。

[weixin_38083061]

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