I'm currently using something like this:
HttpURLConnection con = (HttpURLConnection) u.openConnection ();
con.setDoInput(true);
con.setRequestMethod("POST");
con.setDoInput (true);
con.setDoOutput (true);
con.setRequestProperty ("Content-Type", "application/x-www-form-urlencoded");
out = new DataOutputStream(con.getOutputStream());
String content = "username=" + URLEncoder.encode ("bob")
+ "&password=" + URLEncoder.encode ("smith");
System.out.println("\n" + "sending form to HTTP server ...");
out.writeBytes (content);
out.flush ();
out.close ();
con.connect();
With this I manage to pass some data to my server. What I'm wondering now is how much can be sent this way?
I want to be able to send some xml files (100-200 lines long) and would like to know if I can do this?
Jason
The post body (it's not usually called an argument, since that usually implies it being passed with the URL) can be any length, restricted only by configuration.
Since POST is used to implement file uploads, most systems allow pretty large bodies. 100-200 lines should not be a problem at all, except for the most paranoid configurations out there.
Any length, just keep in mind that your request can timeout. GET data is limited to 4096 bytes.
The maximum length of a post is usually configured in the server configuration, not on client-side.
Related
I have a short Android-Java client program which sends a basic information to bottle-python server with POST method. In the first version of code, server does not show anything. However, In the second version it works but I cannot understand what this additional line do because it has anything to do with posting content. I really appreciate if someone helps me figure this out.(There is nothing wrong with the server code since I can properly send request with python requests and my browsers).
This is the first version of client code:
String url = "http://192.168.1.23:8080/";
URL obj = new URL(url);
HttpURLConnection con = (HttpURLConnection) obj.openConnection();
con.setDoOutput(true);
OutputStream os = con.getOutputStream();
PrintStream myPusher = new PrintStream(os );
myPusher.print("param1=hey");
Second version:
String url = "http://192.168.1.23:8080/";
URL obj = new URL(url);
HttpURLConnection con = (HttpURLConnection) obj.openConnection();
con.setDoOutput(true);
OutputStream os = con.getOutputStream();
PrintStream myPusher = new PrintStream(os );
myPusher.print("param1=hey");
InputStream in= con.getInputStream(); //Nothing changed but only this additional line
Bottle(python) server:
#app.route('/', method="POST")
def hello():
print("it works")
name = request.forms.get("param1")
print(name)
return name
#app.route('/')
def hello():
i=0
print("it works")
run(app, host="192.168.1.23", port=8080)
With first client code server shows nothing.
With second code server shows:
it works
hey
192.168.1.24 - - [31/Dec/2018 17:10:28] "POST / HTTP/1.1" 200 3
Which is as I expected.
With your first code snippet the output stream is still open. So the server does not know if it got the complete request. Probably just closing the stream would work as well.
However, I would make at least a call to getResponseCode to see the outcome of the request.
Your java code seems incomplete for sending a post request.
I think by using this code, you can make it work for yourself.
The PrintStream is a buffered type, this means you should add a flush operation after each print(), or use println() instead.
I requested to send some parameters from java file using post method. I did
String urlParameters = "param1=a¶m2=b¶m3=c";
URL url = new URL("http://testing/index.jsp");
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
writer.write(urlParameters);
writer.flush();
But from receiver's end asks me to send it in body instead of url parameter. I am not sure what I am doing wrong. Please explain me how this code will work and what changes has to be done if I want to send info in request body.
i believe you either need to call the connect() method on the URLConnection at the end, or call a method that would cause the connect to be called for you, like fetching the resulting input stream.
Also you should think about what format the body should be in. Often people like to use standard formats like json, but you will have to decide that between you and the people implementing the server.
I need to send data to another system in a Java aplication via HTTP POST method. Using the Apache HttpClient library is not an option.
I create a URL, httpconection without problems. But when sending special character like Spanish Ñ, the system complains it is receiving
Ñ instead of Ñ.
I've read many post, but I don't understand some things:
When doing a POST connection, and writing to the connection object, is it mandatory to do the URLEncode.encode(data,encoding) to the data being sent?
When sending the data, in some examples I have seen they use the
conn.writeBytes(strData), and in other I have seen conn.write(strData.getBytes(encoding)). Which one is it better? Is it related of using the encode?
Update:
The current code:
URL url = new URL(URLstr);
conn1 = (HttpsURLConnection) url.openConnection();
conn1.setRequestMethod("POST");
conn1.setDoOutput(true);
DataOutputStream wr = new DataOutputStream(conn1.getOutputStream());
wr.writeBytes(strToSend);//data sent
wr.flush();
wr.close();
(later I get the response)
strToSend has been previously URLENCODE.encode(,"UTF-8")
I still don't know if I must use urlencode in my code and/or setRequestProperty("Contentype","application/x-www-formurlencode");
Or if I must use .write(strToSend.getByte(??)
Any ideas are welcome. I am testing also the real server (I dont know very much about it)
How to pass input to a php web page using a automated script ,i.e. i just want to know how pass arguments to text fields using a script. like passing input to username and password field of a web page and then pressing submit button(that too with a script).
favorable language: JAVA
Try Selenium. Selenium is great at automating web browsers.
http://seleniumhq.org/
Also has pure support with Java. But not only.
When it comes to custom methods, see ...
String urlParameters = "param1=a¶m2=b¶m3=c";
String request = "http://example.com/index.php";
URL url = new URL(request);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setDoInput(true);
connection.setInstanceFollowRedirects(false);
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
connection.setRequestProperty("charset", "utf-8");
connection.setRequestProperty("Content-Length", "" + Integer.toString(urlParameters.getBytes().length));
connection.setUseCaches (false);
DataOutputStream wr = new DataOutputStream(connection.getOutputStream ());
wr.writeBytes(urlParameters);
wr.flush();
wr.close();
connection.disconnect();
source (Java - sending HTTP parameters via POST method easily)
if you web page uses the GET method to accept data (i.e. from URL), just connect to the web pages giving the data you want to pass:
http://www.mysite.com/mypage.html?data0=data0,data1=data1
if the web page uses POST things get a little bit more complicated: you have to forge an appropriate HTML request with all your data in the header (as POST method requires)
You can use the Apache HTTPClient - see the example at:
http://hc.apache.org/httpclient-3.x/methods/post.html
This allows you to simulate submitting a fully filled form directly to the destination page and grab the results.
Remember that, after the call, you have to grab and store the session cookie in the response and resubmit it to the following pages you want to "visit" to stay "logged on"
I would like to show how I would do to pass an input to the HTML. I usually use python to send request to the page where I need to input the data. Before doing that you need to know if you need to supply web-cookies or not, if yes, copy the cookie, if you need to be logged in otherwise not, just check that. Once that is done, you need to know the field names for the input area as you will be using them to POST or GET data using your script. Here is sample usage.
import urllib
import urllib2
import string
headers = {'Cookie': 'You cookies if you need'}
values = {'form_name':'sample text', 'submit':''}
data = urllib.urlencode(values)
req = urllib2.Request('website where you making request to',data,headers)
opener1 = urllib2.build_opener()
page1=opener1.open(req)
#OPTIONAL
htmlfile=page1.read()
fout = open('MYHTMLFILE.html', "wb")
fout.write(htmlfile)
fout.close()
I am writing a program in JAVA to POST a large number of XML Documents to a specific web address, in addition to a great deal of other data handling that is slightly unrelated to this question. The only trouble is, I'm expect to handle approximately 90,000 records. When POSTing an XML document, each record takes approximately 10 seconds, 9 of which is taken by receiving the response from the sever after POST.
My question is: Is there a way to POST data to a webserver, then ignore the server's response to save time?
Here is a snip of code that's giving me trouble, it takes approximate 9 seconds according to the system timer to go from "writer.close" to "con.getResponseCode()"
URL url = new URL(TargetURL);
con = (HttpsURLConnection) url.openConnection();
//Login with given credentials
String login = (Username)+":"+(Password);
String encoding = new sun.misc.BASE64Encoder().encode(login.getBytes());
con.setRequestProperty ("Authorization", "Basic " + encoding);
// specify that we will send output and accept input
con.setRequestMethod("POST");
con.setDoInput(true);
con.setDoOutput(true);
con.setConnectTimeout(20000) ; // long timeout, but not infinite
con.setReadTimeout(20000);
con.setUseCaches (false);
con.setDefaultUseCaches (false);
// tell the web server what we are sending
con.setRequestProperty ( "Content-Type", "text/xml" );
OutputStreamWriter writer = new OutputStreamWriter( con.getOutputStream() );
writer.write(data);
writer.flush();
writer.close();
//****This is our problem.*****//
int result = con.getResponseCode();
System.err.println( "\nResponse from server after POST:\n" + result );
I see your problem.
Using the strategy to read only the header would not work for you because the problem is not due to voluminous amount of data the server is sending as a response. The problem is that the server takes a long to time to process the data your client had sent and therefore takes a long time to even send a short ack response.
What you are asking for is Asynchronous response. The answer is AJAX and my preference of choice is GWT.
GWT presents three ways to perform async communication with the server.
GWT RPC
RequestBuilder
javascript include
MVP ClientFactory/EventBus
Please read my description at
http://h2g2java.blessedgeek.com/2009/08/gwt-rpc.html
http://h2g2java.blessedgeek.com/2011/06/gwt-requestbuilder-vs-rpc-vs-script.html
But then, you might prefer to use JQuery, with which I have scant and scarce familiarity.
I'd rather use Apache HttpComponents. It lets you not read the response body, and only the headers which you obviously need.
http://hc.apache.org/httpcomponents-client-ga/tutorial/html/fundamentals.html#d4e143
That part of the docs has an example of only reading a few bytes of the response.