我目前正处于在Android工作室开发Android应用程序的最后阶段。构建APK文件以在设备上运行它们分离到Android工作室模拟器之一。我和安迪安卓模拟器一起去了。我安装了APK，但是当我尝试登录时，即连接到服务器，我得到了一个未知的主机异常，如下所示：
System.err: java.net.UnknownHostException: http://point_collector.netau.net/FetchData.php
System.err: at libcore.net.http.HttpConnection$Address.<init>(HttpConnection.java:282)
System.err: at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
System.err: at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:316)
System.err: at libcore.net.http.HttpEngine.connect(HttpEngine.java:311)
System.err: at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290)
System.err: at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:240)
System.err: at libcore.net.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:81)
System.err: at libcore.net.http.HttpURLConnectionImpl.getOutputStream(HttpURLConnectionImpl.java:197)
System.err: at com.jack.pointcollector.ServerRequests$GetDataAsyncTask.doInBackground(ServerRequests.java:169)
System.err: at com.jack.pointcollector.ServerRequests$GetDataAsyncTask.doInBackground(ServerRequests.java:132)
com.jack.pointcollector W/System.err: at android.os.AsyncTask$2.call(AsyncTask.java:287)
com.jack.pointcollector W/System.err: at java.util.concurrent.FutureTask.run(FutureTask.java:234)
System.err: at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
com.jack.pointcollector W/System.err: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
System.err: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
System.err: at java.lang.Thread.run(Thread.java:856)
服务器请求代码如下：
public class ServerRequests {
//Variables for this class
//Process Dialog informs the user what is happening while thier request is being carried out
//Connection timeout will be the time in milliseconds of how long the connection will last
//Server address is the location of the PHP files
ProgressDialog progressDialog;
public static final int CONNECTION_TIMEOUT = 1000 * 15;
public static final String SERVER_ADDRESS = "http://point_collector.netau.net/";
public ServerRequests(Context context) {
//process dialog requires the context of the class e.g. Register.this or Login.this
progressDialog = new ProgressDialog(context);
progressDialog.setCancelable(false);
progressDialog.setTitle("Processing");
progressDialog.setMessage("Please wait...");
}
public void storeUserData(User user, GetUserCallBack callBack) {
//Process to write to the database to be performed in the background
progressDialog.show();
new StoreDataAsyncTask(user, callBack).execute();
}
public void fetchUserData(User user, GetUserCallBack callBack) {
//Process to read from the database to be performed in the background
progressDialog.show();
new GetDataAsyncTask(user,callBack).execute();
}
public void storeChoreData(Chore chore, GetUserCallBack callBack){
progressDialog.show();
new StoreChoreAsyncTask(chore, callBack).execute();
}
public void storeRewardData(Reward reward, GetUserCallBack callBack){
progressDialog.show();
new StoreRewardAsyncTask(reward, callBack).execute();
}
//Creates a background thread to write to the data base
public class StoreDataAsyncTask extends AsyncTask<Void, Void, Void> {
//instance variables one for a user
//GetUserCallBack is an interface which signals when the operation has been completed
User user;
GetUserCallBack userCallBack;
public StoreDataAsyncTask(User user0, GetUserCallBack callBack0) {
user = user0;
userCallBack = callBack0;
}
@Override
protected Void doInBackground(Void... params) {
try {
//The URL to be connected
//Then we open the connection
//Set the conditions the connection must follow
URL url = new URL(SERVER_ADDRESS + "Register.php");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(CONNECTION_TIMEOUT);
conn.setConnectTimeout(CONNECTION_TIMEOUT);
conn.setRequestMethod("POST");
conn.setDoInput(true);
conn.setDoOutput(true);
//Identifies the objects to be passed for the PHP files
Uri.Builder builder = new Uri.Builder()
.appendQueryParameter("username", user.username)
.appendQueryParameter("password", user.password)
.appendQueryParameter("email", user.email);
//Determines whether the user is creating a parent or child account
if(user.isParent) builder.appendQueryParameter("userType", "Parent");
else builder.appendQueryParameter("userType", "Child");
//Encodes the data for the PHP file
String query = builder.build().getEncodedQuery();
//Records entry
Log.d("query", query);
//Creates an output to send out the query
//Then flushes the writer and closes all outputs
OutputStream os = conn.getOutputStream();
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));
writer.write(query);
writer.flush();
writer.close();
os.close();
//Gets the response code to ensure this was succesful.
int code = conn.getResponseCode();
Log.d("code", Integer.toString(code));
conn.connect();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void aVoid) {
//After the previous method executes we end the process dialog
//and we return the user call back
progressDialog.dismiss();
userCallBack.complete(null);
super.onPostExecute(aVoid);
}
}
public class GetDataAsyncTask extends AsyncTask<Void, Void, User> {
//instance variables one for a user
//GetUserCallBack is an interface which signals when the operation has been completed
User user;
GetUserCallBack userCallBack;
public GetDataAsyncTask(User user0, GetUserCallBack callBack0) {
user = user0;
userCallBack = callBack0;
}
@Override
protected User doInBackground(Void... params) {
//A HashMap to determine what we want to retrieve from the server
//The URL is the location of the PHP file to validate a user
HashMap<String, String> param = new HashMap<>();
String requestURL = SERVER_ADDRESS+"FetchData.php";
param.put("username", user.username);
param.put("password", user.password);
//Checks if a the user logging in is a parent or child
if(user.isParent) param.put("userType", "Parent");
else param.put("userType", "Child");
URL url;
User returnedUser = null;
try {
//Opens the connection to the PHP files
//Sets the conditions of the connection
url = new URL(requestURL);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(CONNECTION_TIMEOUT);
conn.setConnectTimeout(CONNECTION_TIMEOUT);
conn.setRequestMethod("POST");
conn.setDoInput(true);
conn.setDoOutput(true);
//Opens an output stream to send the data to be verified
// and then closes the all output streams and flushes the output writer
OutputStream os = conn.getOutputStream();
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));
writer.write(getPostDataString(param));
writer.flush();
writer.close();
os.close();
//saves the response code to ensure connection was succesful
int code = conn.getResponseCode();
Log.d("code", Integer.toString(code));
//Opens an input stream to retrieve verified data back from the server
//Starts a String Builder to read the data off the input
//Closes the BufferedReader once it has finished building the string
InputStream responseStream = new BufferedInputStream(conn.getInputStream());
BufferedReader responseStreamReader = new BufferedReader(new InputStreamReader(responseStream));
String line;
StringBuilder stringBuilder = new StringBuilder();
while ((line = responseStreamReader.readLine()) != null) { stringBuilder.append(line);}
responseStreamReader.close();
String response = stringBuilder.toString();
Log.d("response", response);
if(response.contains("This is a parent")) {
user.isParent = true;
}
else user.isChild = true;
//Creates a JSON object from the string
JSONObject jsonResponse = new JSONObject(response);
Log.d("length",Integer.toString(jsonResponse.length()));
//Stores the verified user details if the response is not 0
if(jsonResponse.length() > 0) {
if(user.isChild) {
int flag = jsonResponse.getInt("request_flag");
returnedUser = new User(user.username, user.password, flag);
Log.d("returned user", returnedUser.username);
}
else {
returnedUser = new User(user.username, user.password);
Log.d("returned user", returnedUser.username);
}
}
} catch (Exception e) {
e.printStackTrace();
}
return returnedUser;
}
private String getPostDataString(HashMap<String, String> params) throws UnsupportedEncodingException {
//Correctly formats the data to be sent to the PHP file
StringBuilder result = new StringBuilder();
boolean first = true;
for (Map.Entry<String, String> entry : params.entrySet()) {
if (first) first = false;
else result.append("&");
result.append(URLEncoder.encode(entry.getKey(), "UTF-8"));
result.append("=");
result.append(URLEncoder.encode(entry.getValue(), "UTF-8"));
}
return result.toString();
}
@Override
protected void onPostExecute(User returnedUser) {
//After the previous method executes we end the process dialog
//and we return the user call back and return the verified user
progressDialog.dismiss();
userCallBack.complete(returnedUser);
super.onPostExecute(returnedUser);
}
}
public class StoreChoreAsyncTask extends AsyncTask<Void, Void, Void> {
//instance variables one for a chore
//GetUserCallBack is an interface which signals when the operation has been completed
Chore chore;
GetUserCallBack userCallBack;
public StoreChoreAsyncTask(Chore chore0, GetUserCallBack callBack0) {
chore = chore0;
userCallBack = callBack0;
}
@Override
protected Void doInBackground(Void... params) {
try {
//The URL to be connected
//Then we open the connection
//Set the conditions the connection must follow
URL url = new URL(SERVER_ADDRESS + "Chore.php");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(CONNECTION_TIMEOUT);
conn.setConnectTimeout(CONNECTION_TIMEOUT);
conn.setRequestMethod("POST");
conn.setDoInput(true);
conn.setDoOutput(true);
//Identifies the objects to be passed for the PHP files
Uri.Builder builder = new Uri.Builder()
.appendQueryParameter("chore", chore.chore)
.appendQueryParameter("points", chore.points +"")
.appendQueryParameter("parent_name", chore.pname);
//Encodes the data for the PHP file
String query = builder.build().getEncodedQuery();
//Records entry
Log.d("query", query);
//Creates an output to send out the query
//Then flushes the writer and closes all outputs
OutputStream os = conn.getOutputStream();
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));
writer.write(query);
writer.flush();
writer.close();
os.close();
//Gets the response code to ensure this was succesful.
int code = conn.getResponseCode();
Log.d("code", Integer.toString(code));
conn.connect();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void aVoid) {
//After the previous method executes we end the process dialog
//and we return the user call back
progressDialog.dismiss();
userCallBack.complete(null);
super.onPostExecute(aVoid);
}
}
public class StoreRewardAsyncTask extends AsyncTask<Void, Void, Void> {
//instance variables one for a reward
//GetUserCallBack is an interface which signals when the operation has been completed
Reward reward;
GetUserCallBack userCallBack;
public StoreRewardAsyncTask(Reward reward0, GetUserCallBack callBack0) {
reward = reward0;
userCallBack = callBack0;
}
@Override
protected Void doInBackground(Void... params) {
try {
//The URL to be connected
//Then we open the connection
//Set the conditions the connection must follow
URL url = new URL(SERVER_ADDRESS + "Reward.php");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(CONNECTION_TIMEOUT);
conn.setConnectTimeout(CONNECTION_TIMEOUT);
conn.setRequestMethod("POST");
conn.setDoInput(true);
conn.setDoOutput(true);
//Identifies the objects to be passed for the PHP files
Uri.Builder builder = new Uri.Builder()
.appendQueryParameter("reward", reward.reward)
.appendQueryParameter("child", reward.child)
.appendQueryParameter("points", reward.points +"")
.appendQueryParameter("parent", reward.pname);
//Encodes the data for the PHP file
String query = builder.build().getEncodedQuery();
//Records entry
Log.d("query", query);
//Creates an output to send out the query
//Then flushes the writer and closes all outputs
OutputStream os = conn.getOutputStream();
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));
writer.write(query);
writer.flush();
writer.close();
os.close();
//Gets the response code to ensure this was succesful.
int code = conn.getResponseCode();
Log.d("code", Integer.toString(code));
conn.connect();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void aVoid) {
//After the previous method executes we end the process dialog
//and we return the user call back
progressDialog.dismiss();
userCallBack.complete(null);
super.onPostExecute(aVoid);
}
}
}
我的android清单文件中有正确的INTERNET持久性，因为权限都在android的应用程序设置中出现。我做了一些研究，发现它可能是我网址中的下划线？有人可以提供一些帮助吗？
由于
答案 0 :(得分：1)
https://code.google.com/p/android/issues/detail?id=37577
基本上，URL中的_是主机名中的无效字符（尽管不在文件名中）。有些浏览器支持它，但它会导致问题。 Android的默认http实现没有。您需要更改URL（首选），或者需要使用支持它的HTTP库。