我正在尝试制作一个应用程序，我应该将数据从应用程序发送到 Web 服务器。 到目前为止，我一直在搜索并且无法找到一个有效的示例，我发现一些使用 asynctask 的示例不起作用，因此感谢您的帮助！
【问题讨论】：
标签： android web-services android-asynctask
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;
}
}
查看以下链接了解更多信息：-
【讨论】：
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 文件以获取用户名、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>
您必须有 PhpMyAdmin 才能在本地系统中尝试此操作，如果您有托管服务器部分，请尝试使用以下 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：您需要创建在mysql中指定的数据库和表来提供和检索数据
如有错误请留言。
【讨论】：