我正在尝试按照本教程创建登录界面：http ://www.youtube.com/watch?v=etYVqYAhp6w&feature=bf_prev&list=UUnzGVPkz3rZcrLh9jKbKNQw - 第 1 到 6 部分。
当我在 Android 模拟器上运行应用程序时，它返回 toast 消息“登录失败”（下面 Main.java 文件中声明的异常）。
main.java 文件连接到我保存在 wamp/www/index.php 目录中的 php 文件 index.php，然后它与存储在 wamp 服务器（在我的本地机器上）上的“mobiledb”进行通信。
已在数据库中创建了一个用户，我尝试通过模拟器登录，该模拟器应验证登录详细信息并给出 toast 消息“成功！”。
如果有人可以就可能出现的问题提供任何帮助，将不胜感激。谢谢。
主.java
package com.kibriaali.logintutorial;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONObject;
import android.app.Activity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class Main extends Activity implements OnClickListener{
EditText etUser, etPass;
Button bLogin;
//Create string variables that will have the input assigned to them
String username, password;
//Create a HTTPClient as the form container
HttpClient httpclient;
//Use HTTP POST method
HttpPost httppost;
//Create an array list for the input data to be sent
ArrayList<NameValuePair> nameValuePairs;
//Create a HTTP Response and HTTP Entity
HttpResponse response;
HttpEntity entity;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
initialise();
}
private void initialise() {
// TODO Auto-generated method stub
etUser = (EditText) findViewById(R.id.etUser);
etPass = (EditText) findViewById(R.id.etPass);
bLogin = (Button) findViewById(R.id.bSubmit);
//Now to set an onClickListener
bLogin.setOnClickListener(this);
}
public void onClick(View v) {
// This is where we will be working now
//Create new default HTTPClient
httpclient = new DefaultHttpClient();
//Create new HTTP POST with URL to php file as parameter
httppost = new HttpPost("http://127.0.0.1/wamp/www/index.php"); //92.4.131.132 //127.0.0.1 //10.0.2.2
//Assign input text to strings
username = etUser.getText().toString();
password = etPass.getText().toString();
//Next block of code needs to be surrounded by try/catch block for it to work
try {
//Create new Array List
nameValuePairs = new ArrayList<NameValuePair>(2);
//place them in an array list
nameValuePairs.add(new BasicNameValuePair("user", "username"));
nameValuePairs.add(new BasicNameValuePair("pass", "password"));
//Add array list to http post
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
//assign executed form container to response
response = httpclient.execute(httppost); //response from the PHP file
//check status code, need to check status code 200
if(response.getStatusLine().getStatusCode()== 200){
//assign response entity to http entity
entity = response.getEntity();
//check if entity is not null
if(entity != null){
//Create new input stream with received data assigned
InputStream instream = entity.getContent();
//Create new JSON Object. assign converted data as parameter.
JSONObject jsonResponse = new JSONObject(convertStreamToString(instream));
//assign json responses to local strings
String retUser = jsonResponse.getString("user");//mySQL table field
String retPass = jsonResponse.getString("pass");
//Validate login
if(username.equals(retUser)&& password.equals(retPass)){ //Check whether 'retUser' and 'retPass' matches username/password
//Create a new shared preference by getting the preference
//Give the shared preference any name you like.
SharedPreferences sp = getSharedPreferences("logindetails", 0);
//Edit the Shared Preference
SharedPreferences.Editor spedit = sp.edit();
//Put the login details as strings
spedit.putString("user", username);
spedit.putString("pass", password);//May not need to store password
//Close the editor
spedit.commit();
//Display a Toast saying login was a success
Toast.makeText(getBaseContext(), "SUCCESS!", Toast.LENGTH_SHORT).show();
} else {
//Display a Toast saying it failed.
Toast.makeText(getBaseContext(), "Invalid Login Details", Toast.LENGTH_SHORT).show();
}
}
}
} catch(Exception e){
e.printStackTrace();
//Display toast when there is a connection error
//Change message to something more friendly
Toast.makeText(getBaseContext(), "Login Unsuccessful.", Toast.LENGTH_SHORT).show();
}
}//END onClick()
private static String convertStreamToString(InputStream is) {
/*
* To convert the InputStream to String we use the BufferedReader.readLine()
* method. We iterate until the BufferedReader return null which means
* there's no more data to read. Each line will appended to a StringBuilder
* and returned as String.
*/
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
StringBuilder sb = new StringBuilder();
String line = null;
try {
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return sb.toString();
}//END convertStreamToString()
}
索引.PHP 文件
<?php
//turn off error reporting
error_reporting(E_ALL ^ E_NOTICE ^ E_WARNING);
//Create fields for the database
//server, username, password, database
$dbhost = "localhost"; //92.4.131.132 //127.0.0.1 //10.0.2.2
$dbuser = "root";
$dbpass = "";
$dbdb = "mobiledb";
//connect to mySQL
$connect = mysql_connect($dbhost, $dbuser, $dbpass) or die("connection error");
//Select the database
mysql_select_db($dbdb)or die("database selection error");
//Retrieve the login details via POST
$username = $_POST['username'];
$password = $_POST['password'];
//Query the table android login
$query = mysql_query("SELECT * FROM androidlogin WHERE user='$username' AND pass='$password'");
//check if there any results returned
$num = mysql_num_rows($query);
//If a record was found matching the details entered in the query
if($num == 1){
//Create a while loop that places the returned data into an array
while($list=mysql_fetch_assoc($query)){
//Store the returned data into a variable
$output = $list;
//encode the returned data in JSON format
echo json_encode($output);
}
//close the connection
mysql_close();
}
?>
注意：已在 Android 清单文件中启用 Internet 权限。