我遵循了一个关于将使用wamp服务器（在Windows上）运行的MyQSL数据库连接到Android应用程序的youtube教程。 （视频链接为：https://www.youtube.com/watch?v=eldh8l8yPew）
在我的Android Studio代码中，我创建了一个类（名为＆＃34; BackgroundWorker＆＃34;），它扩展了AsyncTask，并且应该处理与连接到数据库的PHP文件的通信。
为了打开写入DB的写入通道，我使用BufferedWriter和OutputStream连接到httpURLConnection对象，该对象具有我的相关php脚本的URL，该脚本位于WAMPSERVER的www文件夹中。
经过这么长时间的生产，我的问题是我在尝试执行以下行时遇到IOException：
OutputStream outputStream = httpURLConnection.getOutputStream();
我已经多次复制了视频教程中的整个代码，所以我怀疑它有什么问题。 我更多地考虑URL设置的方向 - 我的URL对象获取具有地址的String：
String loginURL = "http://10.0.2.2/login.php";
其中＆＃34; login.php＆＃34;是我的PHP脚本，位于wamp服务器的www文件夹中。 我知道10.0.0.2是一种默认地址，可以代替Android Emulator中的localhost，但我怎么使用Genymotion Emulator，所以这可能不是正确的地址？ 我还试图在运行IPCONFIG时看到我看到的所有其他IP地址，但没有更改结果。
我在dubugging方面不太好，所以我使用AsastTask的Toasts和PublishProgress方法来查找和隔离IOException。
以下是我认为可能与IOException相关的部分代码：
我的BackgroundWorker类（扩展了AsyncTask）：
public class BackgroundWorker extends AsyncTask <String , Integer , String> {
Context context;
AlertDialog alertDialog;
public BackgroundWorker(Context userContext) {
this.context = userContext;
}
@Override
protected String doInBackground(String... params) {
// Reading the arguments in the order I sent them in MainActivity
String username = params[0];
String pass = params[1];
String type = params[2];
// Making structure for updating during the wat using Toasts (and showing the first one
int progressValue = 0; // Before if
publishProgress(progressValue);
// Initial String that will hold the text to read from server
String result = "";
// Initial the URL String , the IP address if standart for Android LocalHost
String loginURL = "http://10.0.2.2/login.php";
if (type.equals("login")) {
progressValue++; //1
publishProgress(progressValue);
try {
URL url = new URL(loginURL);
progressValue++; //2
publishProgress(progressValue);
// Building the HttpUrlConnection object
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setDoOutput(true);
httpURLConnection.setDoInput(true);
progressValue++; //3
publishProgress(progressValue);
// Building the writing infrastructure
// IOException occurs after the commit of the next line
OutputStream outputStream = httpURLConnection.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream,"UTF-8"));
progressValue++; //4
publishProgress(progressValue);
// Building the message to the PHP script
String post_data = URLEncoder.encode("user_name" , "UTF-8") + "=" + URLEncoder.encode(username , "UTF-8")
+ "&" + URLEncoder.encode("user_pass" , "UTF-8") + "=" + URLEncoder.encode(pass , "UTF-8");
progressValue++; //5
publishProgress(progressValue);
// Writing the data
bufferedWriter.write(post_data);
progressValue++; //6
publishProgress(progressValue);
// Closing all writing structures
bufferedWriter.flush();
bufferedWriter.close();
outputStream.close();
// Building the Reading Infrastructure
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream , "iso-8859-1"));
// Reading the data
String line;
while ((line = bufferedReader.readLine()) != null) {
result += line;
}
// Closing all reading structures
bufferedReader.close();
inputStream.close();
httpURLConnection.disconnect();
} catch (MalformedURLException e) {
e.printStackTrace();
progressValue = 10;
publishProgress(progressValue);
} catch (IOException e) {
progressValue = 11;
publishProgress(progressValue);
e.printStackTrace();
}
}
return result;
}
@Override
protected void onProgressUpdate(Integer... values) {
int progressValue = values[0];
// Before IF statement
if (progressValue == 0) Toast.makeText(this.context , "Before if" , Toast.LENGTH_SHORT).show();
// After IF statement
if (progressValue == 1) Toast.makeText(this.context , "After if" , Toast.LENGTH_SHORT).show();
// After URL statement
if (progressValue == 2) Toast.makeText(this.context , "After URL Setting" , Toast.LENGTH_SHORT).show();
// Before Writing data
if (progressValue == 3) Toast.makeText(this.context , "After making HTML" , Toast.LENGTH_SHORT).show();
// After Writing data
if (progressValue == 4) Toast.makeText(this.context , "After making writing infra" , Toast.LENGTH_SHORT).show();
// After Writing data
if (progressValue == 5) Toast.makeText(this.context , "Before Writing data" , Toast.LENGTH_SHORT).show();
// After Writing data
if (progressValue == 6) Toast.makeText(this.context , "After Writing data" , Toast.LENGTH_SHORT).show();
// After Writing data
if (progressValue == 10) Toast.makeText(this.context , "First exception" , Toast.LENGTH_SHORT).show();
// After Writing data
if (progressValue == 11) Toast.makeText(this.context , "IO Exception" , Toast.LENGTH_SHORT).show();
}
@Override
protected void onPreExecute() {
alertDialog = new AlertDialog.Builder(context).create();
alertDialog.setTitle("Login Status");
}
@Override
protected void onPostExecute(String result) {
alertDialog.setMessage(result);
alertDialog.show();
}
}
这是我的login.php代码：
<?php
require "conn.php";
$user_name = $_POST["user_name"];
$user_pass = $_POST["user_pass"];
$mysql_qry = "select * from employee_data where user like '$user_name' and password like '$user_pass';";
$result = mysqli_query($conn ,$mysql_qry);
if(mysqli_num_rows($result) > 0) {
echo "login success";
}
else {
echo "login not seccess";
}
?>
conn.php是另一个只是连接数据库的脚本。 当我直接通过broswer运行我的login.php脚本时 - 它运行正常。
非常感谢， 我希望你能理解这个问题， 诺姆
答案 0 :(得分：0)
我自己解决了。 IP地址不正确，因为我使用Genymotion Emulator我必须将IP更改为192.168.56.1 现在一切正常。