My code is like the following:
URLConnection cnx = address.openConnection();
cnx.setAllowUserInteraction(false);
cnx.setDoOutput(true);
cnx.addRequestProperty("User-Agent",
"Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)");
InputStream is = ...
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I am using a URLConnection class - I want to be able to grab a stream to a given URL even if said URL is unavailable (ie cache the last known ... |
I can't understand why Java HttpURLConnection doesn't follow redirect. I use the following code to get this page:
import java.net.URL;
import java.net.HttpURLConnection;
import java.io.InputStream;
public class Tester {
public static ...
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I'm trying to parse a webpage using Java with URLConnection. I try to set up the user-agent like this:
java.net.URLConnection c = url.openConnection();
c.setRequestProperty("User-Agent", "Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.4; en-US; ...
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URL url = new URL("http://www.example.com/comment");
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setRequestMethod("POST");
Is
connection.setRequestProperty(key, value);
the same as
OutputStreamWriter writer = new OutputStreamWriter(connection.getOutputStream());
writer.write("key=" + value);
writer.close();
?
If not, please correct me.
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My application needs some web scraping functionality. I have URL object that downloads all the data. But I need to scrape many pages and I create many URL objects so I ... |
Simple stuff, I am learning URLs/Networking in my class and I am trying to display something on a webpage. Later I am going to connect it to a MySQL DB... anyway ... |
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Hi
I wrote a program that downloads some files from some servers.
Currently program works properly.
But I want to add resume support to it.
I'm doing it like this But the result file is ... |
I want to ask a basic problem in Java. What is the difference between URLConnection, HttpURLConnection and HttpsURLConnection (with SSL). Under what conditions, which one should I use? Can provide some ... |
Is there an equivalent of the java.net.URLConnection class
in .NET. , for example the HttpWebRequest? What else could be used?
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All,
I am trying to identify plain text files with Mac line endings and, inside an InputStream, silently convert them to Windows or Linux line endings (the important part is the LF ... |
I'm trying to write out to URLConnection#getOutputStream, however, no data is actually sent until I call URLConnection#getInputStream. Even if I set URLConnnection#doInput to false, it ... |
I try to get data from latata.pl/pl.php and view all sign (polish - iso-8859-2)
final URL url = new URL("http://latata.pl/pl.php");
final URLConnection urlConnection = url.openConnection();
...
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I want to check progress of downloading file by URLconnection. Is it possible or should I use another library? This is my urlconnection function:
public static String sendPostRequest(String httpURL, String data) throws ...
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I'm downloading various files through I/O-streaming in my Java application. Receiving and saving those files works well as long as I have a full URL-path including file name, but how can ... |
I'm looking to load the version of a site within the Noscript tags so the connection has to appear like it has Javascript disabled.
Thanks!
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Hey, have been trying to work this out for last day or so but hitting brick wall. Trying to unit test this bit of code. But not sure if need to ... |
Where can I get all the details about the protocols we can use in java to make a URL connection.
like : for jar its jar:file:///c|/!/ what does this notaion mean ?
what ... |
I should download an attachment sent to me by an HTTP POST.
I've make the request, setting Content-Type to "application/x-www-form-urlencoded", but i dont recieve the file.
Should I send some other headers to ... |
My Name is Rohit Kumawat
I am creating a Download Manager in Java Language. I have almost created it with support for FTP,HTTP & HTTPS(Using JSSE 3.0). Now i want to capture ... |
This question could be a bit difficult to find the answer. It's a questions in one series with What is the reason that Policy.getPolicy() is considered as it will ... |
I specifically require usage examples/docs for the functions "getContent" and "getContent(class)" which are part of java.net.urlconnection ... I tried googling, but could not find any good examples for these functions...
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I've created a servlet which reads the content of a file to a byte array which subsequently is written to the OutputStream of the response:
// set headers
resp.setHeader("Content-Disposition","attachment; filename=\"file.txt\"");
resp.setHeader("Content-Length", "" + fileSize);
// ...
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I have an internet application and with this one i wanna open a URLConnection and say to java that I'm not the person that login on pc, but another one.
I explain ... |
In Blogger post I have this snippet
<applet codebase="https://droidsnip.googlecode.com/hg/" height="300" archive="text.jar" width="300" code="Google.class">
and have this java code stored at google code:
public class Google extends java.applet.Applet {
... |
Hello Friends, I am making a chat applet server application. I have made it with Sockets but as socket doesnt work behind proxies ( till i know, if you know how to get a socket in an applet to work behind a firewall then it will solve all my problem.) But rite now i am trying to work with URLConnection. I ... |
import java.net.*; import java.io.*; public class Yahoo { public static void main( String args[] ) { try { URL yahoo = new URL("http://www.yahoo.com/"); URLConnection urlConn = yahoo.openConnection(); BufferedReader br = new BufferedReader( new InputStreamReader( urlConn.getInputStream() ) ); String lineIn = ""; while( ( lineIn = br.readLine()) != null ) { System.out.println( lineIn ); } br.close(); } catch( Exception e ) { ... |
Read this beautiful Javaworld article explaining the URL/URLConnection classes and the hidden traps:- http://www.javaworld.com/javaworld/jw-03-2001/jw-0323-traps.html The author says that it is con.getInputStream() which actually posts the request to the server !! 1. When we do con.getOutputStream() and write to the output stream, actually that writing is done to a local buffer- NOT to the server. 2. When we do con.getInputStream()- it is ... |
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Hi, I have two doubts : 1. I am trying to connect to some site using URLConnection. But I am behind a proxy. How can I do it to connect to that site? In my code I use the following to cross proxy : System.getProperties().put( "proxySet", "true" ); System.getProperties().put( "proxyHost", "my proxy ip" ); System.getProperties().put( "proxyPort", "8080" ); String password = ... |
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I am trying to read a POST result from a certain URL. If the request page (where you will fill out a form and click submit) and the response page (where the result is shown) are the same URL, it is easy. You write the post parameters to the URL and then open an inputstream to read the result. However, how ... |
I have a program that goes out to a website and retrieves some information for me. My problem is that I have it read another url out of the page and then connect to it. Put after so long it just stops and does not move. Is there some time frame that I need to look at or some thing with ... |
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Yup. We were having this problem with WebSphere 4.0. Struts actions that worked under Tomcat and WebLogic broke all of a sudden under WebSphere 4.0. If you're going to do an HttpServletResponse.getOutputStream() and write to it, flushing the stream isn't enough; you have to close the stream before your action returns, or you'll get a 500. - James |
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Yes, you can do all that by hand, but it would require your knowing the details of the HTTP protocol (and perhaps HTTPS, FTP, and other Internet protocols.) Potentially, this could include all sorts of complexities: dealing with proxies, SSL, partial transmissions, error handling, etc. You might need to sit down and study all these things so that you could implement ... |
hi my robot is tracking an html page containing certain links to several text files. whenever it finds a text file added on the current date it fires a mail. however, to prevent it from continuously mailing, i have put in a check to get the lastmodified() of the txt file. however, the lastmodified returned to me is some dec31, 1969 ... |
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Hi All, I'm having a problem using URLConnections that I'm hoping someone can shed some light on. The basic problem is: if a client creates numerous URLConnections very rapidly, eventually it stops being able to open any more connections without waiting a few minutes for a resource (client ports?) to be released. I've simplified the problem down to a relatively simple ... |
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Hi, The method URLConnection.getHeaderFields() gets the header fields but it is supported by jre 1.4 onwards. But i am using jre 1.3 so i cannot use this method, instead i am using URLConnection.getHeaderField("HeaderName") which is supported by jre 1.3..But through this method i am getting only the last part of the header and i am not getting the entire header value. ... |
Hello everyone, I am using HTTP protocol to transfer large amount of data across two machines. And I have found out that some packages will be lost when using the following source codes. I am wondering whether there are anything wrong or potential issues in them. Data request URLConnection conn = url.openConnection(); conn.connect(); InputStream is = conn.getInputStream(); while (true) { // ... |
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Class URL represents a Uniform Resource Locator, a pointer to a "resource" on the World Wide Web. A resource can be something as simple as a file or a directory, or it can be a reference to a more complicated object, such as a query to a database or to a search engine. |
Hi I am using URLConnection class to read some data from a specific website where the data gewts updated everyday.We are accessing this through our proxy server.Some times when we access the site through out program we are gettgin old data where as if we access the same url form a browser we are getting latest data. is there anyway we ... |
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Hi, I am having a problem connecting to a URL from within a servlet. The URL I am trying to connect to is a CGI Program that has some parameters passed as part of the URL (as in a GET) and a few FORM parameters (as in a POST). If I access the URL directly through a browser, everything works perfectly ... |
No, URLConnection assumes the HTTP protocol of one request, one response. For performance reasons a web server can keep a channel open to a client, but the HTTP protocol applies regardless. You could do "client/server" by opening a general socket connection, but it won't work for general clients on the Internet because a lot of clients are behind firewalls that only ... |
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Your code is fine to some extent. I dont really understand what you really mean by 'connection is active or not'. If the openConnection method is successfull (without exception), it definitely means that the connection to the server is established. If the servlet does not get invoked, it indicates invalid usage of HTTP Protocol. If you use setdooutput(true) and setdoinput(true), you ... |
Hello, I'm using the code below to post to an address using URLConnection. But I need it to show up in the address area. I can't send a doGet request and I was wondering if there was a work around or something that would just change the URL to the actual URL it is posting to. import java.io.*; import javax.servlet.*; import ... |
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Originally posted by javabeans: Hi.. i m using urlconnection class in one servlet(say connecttoServer.java) to connect another servlet. After fist read and write connection becomes null. Is there any way to connect to same servlet? also plz guide me to know How to connect to another servlet from connecttoServer.java? thx in advance... |
Hi all, I have a url where the content is XML and it has XSL file specified. Now, when I go to that url from the browser and do view source I see the XML data BUT from the java program when I make connection and read the data via BufferedReader I get HTML (that means somewhere its making XSL applied). ... |
Thanks Horatio, I'll check that link out in a minute. At the moment I'm having an annoyance with reading from a DataInputStream. I'm trying to read in a plain text file, about 85kb, but sometimes it does not read it all....it mostly finishes the file too early. Here is the code I have: import java.io.*; import java.net.*; class fileReader {//start of ... |
Using java.net package, I am trying to read a html page, which has Content-Type as code: Now it is very critical for me to be able to read the charset which is mentioned in tag above. Using urlConnection.getContentType(), urlConnection.getHeaderField("Content-Type") just returns "text/html", which I believe is because the above methods derive value from some other place ... |
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I'm having problem with url connection...the code to download content at my home does not run at my institute's pc... import java.net.*; import java.io.*; class URLConn { public static void main (String args[]) throws Exception { URL url = new URL ("http://www.google.co.in"); URLConnection conn = url.openConnection (); System.out.println ("before stream connection"); InputStream is = conn.getInputStream (); System.out.println ("after stream connection"); int ... |
Hi Members, I have to connect a URL; but for only certain time interval. Now im using UrlConnection.connect(); But it loops around for one or more attempt whether it could make a connection. Instead i need to connect for certain time interval say 3 seconds; if the url specified is connected within the time interval; it should return 'true' or if ... |
I want my url connection to timeout after a few seconds but it continues to try to connect past the timeout. Has anyone ever seen this before? I.E. // Start a timer here try { URL url = new URL("http://hello"); URLConnection conn = url.openConnection(); conn.setConnectTimeout(2000); // 2 seconds conn.connect(); } catch (Exception e) { //Should get a timeout here if connection ... |
Hi all, I am trying java networking programming, just for fun during my summer time. i try to connect to a website using java. To test the whether the code actually connect to a website, i put a page view counter in my blog and used the code to connect to it. However, page view counter doesn not increase when the ... |
In that case, you are doing things correctly on the client side, you just are expecting incorrect results on the server side. If I were using a JEE app for this, my goal would be to write a Servlet that maps to the /test2.htm URL. It would read the InputStream coming in from the client, then write a response in kind. ... |
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Hi, We are executing the following code to print encodingtype etc. But we are getting null value. why is the actual value not printed. I am unable to find out. any help is welcome. I am giving the code below. import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.net.MalformedURLException; import java.net.URL; import java.net.URLConnection; import java.util.Date; import java.util.logging.Level; import java.util.logging.Logger; public class URLCall ... |
Well, you don't usually "call" a Java source file, whatever that might mean, so it's hard to tell what your question means. However as a general rule, if you want to cause a program on a different computer to start executing, you will have to contact some server on that other computer which will make that happen for you. Obviously it ... |
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27.12.2010 13:31:29 org.apache.catalina.core.StandardWrapperValve invoke SEVERE: Servlet.service() for servlet jsp threw exception java.io.IOException: Server returned HTTP response code: 505 for URL: http://localhost/AgroZoo10/jsp/Thesaurus.jsp?p3=dog flea at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1313) at mc.Crawler_old_moj.addRelevantLinksTo_vectorToSearch(Crawler_old_moj.java:158) at mc.Crawler_old_moj.addRelevantLinksTo_vectorToSearch(Crawler_old_moj.java:301) at mc.Crawler_old_moj.addRelevantLinksTo_vectorToSearch(Crawler_old_moj.java:301) at mc.Crawler_old_moj.(Crawler_old_moj.java:99) at org.apache.jsp.jsp.catchAjaxRequest_jsp._jspService(catchAjaxRequest_jsp.java:350) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) at javax.servlet.http.HttpServlet.service(HttpServlet.java:803) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:337) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266) at javax.servlet.http.HttpServlet.service(HttpServlet.java:803) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:738) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at com.planetj.servlet.filter.compression.CompressingFilter.doFilter(CompressingFilter.java:222) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at ... |
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Hello, I am retriving some data based on URL. This URL internally acts as webservice client to fetch data from other location and returns back the data. There are chances that the webservice will be down which will directly impact in fetching the data. What percaution should be taken to avoid such scenario? Is there any way we can add some ... |
I dont want to set cookies anymore in the java code, my requirement is follows Let's say I have opened a website from browser and logged into it, in this process the website has created some cookies in my browser, now I want to make a new request to the same website with slightly different url (like for retrieving user profile ... |
I've written a program based off a game called Runescape. This program looks up a given item's price. Here it is: Java Code: import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.InputStreamReader; import java.io.OutputStreamWriter; import java.net.URL; import java.net.URLConnection; import java.net.URLEncoder; import java.util.regex.Matcher; import java.util.regex.Pattern; public class RSGrandExchange { public static void main(String[] args) throws Exception { long t_i = System.currentTimeMillis(); String item = "blue ... |
Hello, I have two questions about urlconnection. First, when trying to connect to a site that also has a mobile version, the site keeps responding with the mobile version. How can I make it take me to the normal site? I asked this question before, and someone told me to try setting the user agent. I set the user agent and ... |
12-20-2011 02:07 AM #1 tnrh1 Senior Member Join Date Aug 2011 Posts 116 Rep Power 0 URLConnection Hello everyone, I'm trying to copy an html file to a string. My problem is that some of the notes are not copied well. Here is the source code: Java Code: URL mz = new URL("http://www.mzhiphop.com"); URLConnection Cmz = mz.openConnection(); BufferedReader in ... |
I need to send information to a webpage via a textbox so that it will give me back the data I need. Unfortunately, there are several boxes on the page and merely trying to use an OutputStreamWriter doesn't do anything for me. I'm using the following code, which I got from the SUn website anyway, so I imagine it's correct. URL ... |
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No, Since I didn't particularly intend to install the upgrade myself, but I have now and nothing seems relevant. This is a moderately significant piece of functionality, and they have no business changing it in a minor bug fix release. By the way, when constructing my example I first accidentally put in the header key without the hyphens and that did ... |
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I am just wondering what could be the difference in the results of the following two approaches. I am trying to load a web page from www.oanda.com. One approach is to read from the input stream associated with URLConnection object. Another one is to use socket and send the following request to the server GET / HTTP/1.1 User-Agent: Simple Web Client ... |
JFactor2004 wrote: Basically what I'm trying to do is visit and log in to a website. It's not just a simple POST request however, in that after you login, some more stuff actually happens between the server and your browser before you're "logged in" so I'm trying to reproduce everything that happens and I'm not sure how much of that will ... |
You can't reuse the HttpURLConnection object. But the underlying connection does follow the HTTP 1.1 protocol for persistent connections (which doesn't just allow for, but says they should be the default) to the server. You don't have much control over it though, Java handles it invisible to the API. The API for HttpURLConnection tells us that the underlying socket connection may ... |
This is a complicated thing. I have used apache's httpclient and ftpclient in the past to circumvent this. The problem is that it then takes you away from URL + URLConnection. Also, I'm not sure you can do SSL with that. I recommend you look around the web. I found some good examples of how to do CGI when I was ... |
I am trying to connect to a URL in hopes of feeding information to a PHP script, after trying a lot of different ways to do it, I am stumped. Any advice would be greatly appreciated, the present code is as follows: try { URL url = new URL(null, "https://www.blargh.com/gateway.php?seccode=da39a35e6b4b0d3255bfef956090afd80709&time=10minutes&username=anon@gmail.com&password=pass"); URLConnection myConnection = url.openConnection(); myConnection.connect(); } catch (MalformedURLException e) { // ... |
Ok thanks, I tried your example and now it displays full HTML (well it looks like full html anyway). I also added a counter to see whether the number of HTML lines would remain the same every time the URL is accessed and it outputs a slightly different number every time. For example, the number of html lines varied from 2659 ... |
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You're talking about JSP/Servlets? In the future please post related questions at the JSP or Servlet forum. Back to your actual question: the complete picture is unclear. Please try asking the question the smart way. Where is the code located, how is the initial request invoked and where to you want so send the one and the other to. |
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OK lol, fair enough. What I'm trying to do is create a login system to a website from within a Java app, I want to display the username and password fields in a Java GUI and submit these to the website. What I'm also trying to fathom out is how I can display the verification image - I can easily download ... |
I've asked a question recently about setting the source ip address when fetching an html page using URLConnection, I've been told this isn't possible, I would like to use URLConnection to retrieve html files but I need the ability to set the source ip. Currently I use Apache HttpClient but I am having many issues with it so I would like ... |
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