I'm trying to read URL in java, and it works as long as the URL is loading in browser.
But if it is just cylcing in the browser and not loading that page when I'm trying to open it in my browser, my java app just hangs, it will probably wait forever given enough time. How do I set timeout on that or something, if its loading for more than 20 seconds that I stop my application?
I'm using URL
Here is a relevant part of the code :
URL url = null;
String inputLine;
try {
url = new URL(surl);
} catch (MalformedURLException e) {
e.printStackTrace();
}
BufferedReader in;
try {
in = new BufferedReader(new InputStreamReader(url.openStream()));
while ((inputLine = in.readLine()) != null) {
System.out.println(inputLine);
}
in.close();
} catch (IOException e) {
e.printStackTrace();
}
I don't know how u are using the URL class. It would have been better if post a snippet. But here is a way that works for me. See if it helps in your case:
URL url = new URL(urlPath);
URLConnection con = url.openConnection();
con.setConnectTimeout(connectTimeout);
con.setReadTimeout(readTimeout);
InputStream in = con.getInputStream();
The URL#openStream method is actually just a shortcut for openConnection().getInputStream(). Here is the code from the URL class:
public final InputStream openStream() throws java.io.IOException {
return openConnection().getInputStream();
}
You can adjust settings in the client code as follows:
URLConnection conn = url.openConnection();
// setting timeouts
conn.setConnectTimeout(connectTimeoutinMilliseconds);
conn.setReadTimeout(readTimeoutinMilliseconds);
InputStream in = conn.getInputStream();
Reference: URLConnection#setReadTimeout, URLConnection#setConnectTimeout
Alternatively, you should set the sun.net.client.defaultConnectTimeout and sun.net.client.defaultReadTimeout system property to a reasonable value.
If you are using a URLConnection (or HttpURLConnection) to "read from a url" you have a setReadTimeout() method which allows you to control that.
Edited after you posted the code:
URL url = null;
String inputLine;
try {
url = new URL(surl);
} catch (MalformedURLException e) {
e.printStackTrace();
}
BufferedReader in;
try {
URLConnection con = url.openConnection();
con.setReadTimeout( 1000 ); //1 second
in = new BufferedReader(new InputStreamReader(con.getInputStream()));
while ((inputLine = in.readLine()) != null) {
System.out.println(inputLine);
}
in.close();
} catch (IOException e) {
e.printStackTrace();
}
You should add internet permission in AndroidMenifest.xml
<uses-permission android:name="android.permission.INTERNET" />
and add it in the main function:
if (android.os.Build.VERSION.SDK_INT > 9)
{
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
}
Related
I'm getting a little bit confused about how properly close/manage an URLConnection/HttpURLConnection, the next code shows how I'm deal with it:
String someIP = "...";
URL url = new URL(someIP);
try (BufferedReader br = new BufferedReader(new InputStreamReader(url.openStream()))) {
while ((res = br.readLine()) != null) {
cad.append(res);
}
}
I'm thinking to change the implementation to the next one, using an HttpURLConnection and closing later in finally clause:
String someIP = "...";
URL url = new URL(someIP);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
try (InputStreamReader isr = new InputStreamReader(conn.getInputStream());
BufferedReader br = new BufferedReader(isr)) {
while ((res = br.readLine()) != null) {
cad.append(res);
}
}
catch (Exception e) {
//ex....
}
finally {
if (conn != null) {
conn.disconnect();
}
}
It is enough to use a try with resources to properly close the BufferedReader, InputStreamReader and URLConnection? Or the second implementation is better, what advices could you give me to handle it.
I have implemented a class using HttpUrlConnection to get some data from the google geocoding api. When I'm using this code on android, it works properly. But as soon as I am using this code in another "normal" java program, I am getting the status-code 400 (BadRequest) sometimes. Here is my code:
HttpURLConnection c = null;
StringBuilder sb = new StringBuilder();
try {
URL u = new URL(url);
c = (HttpURLConnection) u.openConnection();
c.setRequestMethod("GET");
c.setRequestProperty("Content-length", "0");
c.setUseCaches(false);
c.setAllowUserInteraction(false);
c.setConnectTimeout(timeout);
c.setReadTimeout(timeout);
c.connect();
int status = c.getResponseCode();
switch (status) {
case HttpURLConnection.HTTP_OK:
case HttpURLConnection.HTTP_CREATED:
BufferedReader br = new BufferedReader(new InputStreamReader(c.getInputStream()));
String line;
while ((line = br.readLine()) != null) {
sb.append(line + "\n");
}
br.close();
}
} catch (SocketTimeoutException ex){
// Handle ...
} catch (MalformedURLException ex) {
// Handle ...
} catch (IOException ex) {
// Handle ...
} finally {
if (c != null) {
try {
c.disconnect();
} catch (Exception ex) {
}
}
}
I have a reliable internet connection and also the URL I am using to receive the data works, whenever I try it with my web browser.
Thanks in advance!
Bad Request is often caused by inadequat URLs. As you mentioned not every URL gives this error, only a view of them. So it has to be something to do with that. Try the following code to ensure the correct encoding of the URL you are using:
String url = ...; // your url
url = URLEncoder.encode(url,"UTF-8");
// Use 'url' ...
I'm trying to POST some data to an https url, in my android application, in order to get a json format response.
I'm facing two problems:
is = conn.getInputStream();
throws
java.io.FileNotFoundException
I don't get if i do something wrong with HttpsURLConnection.
The second problem arose when i debug the code (used eclipse); I set a breakpoint after
conn.setDoOutput(true);
and, when inspecting conn values, I see that the variable doOutput remain set to false and type GET.
My method for https POST is the following, where POSTData is a class extending ArrayList<NameValuePair>
private static String httpsPOST(String urlString, POSTData postData, List<HttpCookie> cookies) {
String result = null;
HttpsURLConnection conn = null;
OutputStream os = null;
InputStream is = null;
try {
URL url = new URL(urlString);
conn = (HttpsURLConnection) url.openConnection();
conn.setReadTimeout(10000);
conn.setConnectTimeout(15000);
conn.setRequestMethod("POST");
conn.setUseCaches (false);
conn.setDoInput(true);
conn.setDoOutput(true);
if(cookies != null)
conn.setRequestProperty("Cookie",
TextUtils.join(";", cookies));
os = conn.getOutputStream();
BufferedWriter writer = new BufferedWriter(
new OutputStreamWriter(os, "UTF-8"));
writer.write(postData.getPostData());
writer.flush();
writer.close();
is = conn.getInputStream();
BufferedReader r = new BufferedReader(
new InputStreamReader(is));
StringBuilder total = new StringBuilder();
String line;
while ((line = r.readLine()) != null) {
total.append(line);
}
result = total.toString();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (ProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (os != null) {
try {
os.close();
} catch (IOException e) {
}
}
if (is != null) {
try {
is.close();
} catch (IOException e) {
}
}
if (conn != null) {
conn.disconnect();
}
}
return result;
}
A little update: apparently eclipse debug lied to me, running and debugging on netbeans shows a POST connection. Error seems to be related to parameters i'm passing to the url.
FileNotFoundException means that the URL you posted to doesn't exist, or couldn't be mapped to a servlet. It is the result of an HTTP 404 status code.
Don't worry about what you see in the debugger if it doesn't agree with how the program behaves. If doOutput really wasn't enabled, you would get an exception obtaining the output stream.
I all but copied the following code from here. I get a java.net.SocketException on line 10 saying "Connection Reset".
import java.net.*;
import java.io.*;
import org.apache.commons.io.*;
public class HelloWorld {
public static void main(String[] x) {
try {
URL url = new URL("http://money.cnn.com/2013/06/07/technology/security/page-zuckerberg-spying/index.html");
URLConnection con = url.openConnection();
InputStream in = con.getInputStream();
String encoding = con.getContentEncoding();
encoding = encoding == null ? "UTF-8" : encoding;
String body = IOUtils.toString(in, encoding);
System.out.print(body);
} catch (Exception e) {
e.printStackTrace();
}
}
}
I'm worried this may not actually be an issue with the actual code but rather some permission I need to give Java. Is there something wrong with my code or is this an environment issue?
I used your code with small modification cause I don't have IOUtils at hands. And it works as it should. There is no need to set agent. No special privileges also as I run it by normal user.
try {
URL url = new URL("http://money.cnn.com/2013/06/07/technology/security/page-zuckerberg-spying/index.html");
URLConnection con = url.openConnection();
InputStream in = con.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(in));
StringBuilder sb = new StringBuilder();
String line = br.readLine();
while (line != null) {
sb.append(line);
line = br.readLine();
}
System.out.print(sb.toString());
} catch (Exception e) {
e.printStackTrace();
}
Please tell me some one, How to resolve this problem,
Sometime I am getting Filenotfound Exception and Some time this code working fine.
Below is my code,
public String sendSMS(String data, String url1) {
URL url;
String status = "Somthing wrong ";
try {
url = new URL(url1);
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
conn.setRequestProperty("User-Agent","Mozilla/5.0 ( compatible ) ");
conn.setRequestProperty("Accept","*/*");
OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
wr.write(data);
wr.flush();
// Get the response
try {
BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String s;
while ((s = rd.readLine()) != null) {
status = s;
}
rd.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
}
wr.close();
} catch (MalformedURLException e) {
status = "MalformedURLException Exception in sendSMS";
e.printStackTrace();
} catch (IOException e) {
status = "IO Exception in sendSMS";
e.printStackTrace();
}
return status;
}
Rewrite like this and let me know how you go... (note closing of reading and writing streams, also the cleanup of streams if an exception is thrown).
public String sendSMS(String data, String url1) {
URL url;
OutputStreamWriter wr = null;
BufferedReader rd = null;
String status = "Somthing wrong ";
try {
url = new URL(url1);
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
conn.setRequestProperty("User-Agent","Mozilla/5.0 ( compatible ) ");
conn.setRequestProperty("Accept","*/*");
wr = new OutputStreamWriter(conn.getOutputStream());
wr.write(data);
wr.flush();
wr.close();
rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String s;
while ((s = rd.readLine()) != null) {
status = s;
}
rd.close();
} catch (Exception e) {
if (wr != null) try { wr.close(); } catch (Exception x) {/*cleanup*/}
if (rd != null) try { rd.close(); } catch (Exception x) {/*cleanup*/}
e.printStackTrace();
}
return status;
}
This issue seems to be known, but for different reasons so its not clear why this happend.
Some threads would recommend closing the OutputStreamWriter as flushing it is not enough, therefor i would try to clos it directly after fushing as you are not using it in the code between the flush and close.
Other threads show that using a different connections like HttpURLConnection are avoiding this problem from occuring (Take a look here)
Another article suggests to use the URLEncoder class’ static method encode. This method takes a string and encodes it to a string that is ok to put in a URL.
Some similar questions:
URL is accessable with browser but still FileNotFoundException with URLConnection
URLConnection FileNotFoundException for non-standard HTTP port sources
URLConnection throwing FileNotFoundException
Wish you good luck.
It returns FileNotFoundException when the server response to HTTP request is code 404.
Check your URL.