CODEWITHSUNDEEP
javajsphttprequest
Qafqaz Qafqaz
Qafqaz Qafqaz

Reputation: 89

How do I send a POST request in Java?

When I send request from JSP I use this code

<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>

<form method="post"  action="http://translate.intelsoft.az" id="tform" name="ftext">
<input class="gogo1"  value="a" name="l" id="l1" /> <div class="il">
<p>Rusca</p>
<textarea class="ilkin1" name="t" id="t1" >
выыававыавыавыавфыа
выыававыавыавыавфыа
выыававыавыавыавфыа
выыававыавыавыавфыа</textarea>
<div><input class="gogo" type="submit" value="Tərcümə1" name="b1" /></div></div>    </form>

</body>
</html>

and the response is correct, so that I see my parameter's value. But when I send from Java I get no correct response. I think that the parameters are not sent correctly. Here's my Java code:

String urlParameters = "t=выыававыавыавыавфыа&l=a";
String request = "http://translate.intelsoft.az";
URL url = null;
try {
    url = new URL(request);
} catch (MalformedURLException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
} 
HttpURLConnection connection = null;
try {
    connection = (HttpURLConnection) url.openConnection();
} catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}           
connection.setDoOutput(true);
connection.setDoInput(true);
connection.setInstanceFollowRedirects(false); 
try {
    connection.setRequestMethod("POST");
} catch (ProtocolException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
} 
connection.setRequestProperty("Content-Type", "text/html"); 
connection.setRequestProperty("charset", "utf-8");
connection.setRequestProperty("Content-Length", "" + Integer.toString(urlParameters.getBytes().length));
connection.setUseCaches (false);

DataOutputStream wr;
try {
    wr = new DataOutputStream(connection.getOutputStream ());
    wr.writeBytes(urlParameters);
    wr.flush();

    BufferedReader rd = new BufferedReader(new InputStreamReader(connection.getInputStream()));
    String line;
    while ((line = rd.readLine()) != null) {
        System.out.println(line);
    }
    wr.close();





    connection.disconnect();
} catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}

What is wrong here?

Upvotes: 1

Views: 11047

Answers (1)

BalusC
BalusC

Reputation: 1108537

First, your JSP page is using UTF-8 character encoding.

<%@ page ... pageEncoding="UTF-8"%>

However, your Java code isn't using the same character encoding.

DataOutputStream wr;
try {
    wr = new DataOutputStream(connection.getOutputStream ());
    wr.writeBytes(urlParameters); // <--- Wrong! Uses platform default encoding.
    wr.flush();

You need to replace that troublesome piece by

try {
    connection.getOutputStream().write(urlParameters.getBytes("UTF-8"));

Note that the whole DataOutputStream decoration is unnecessary. It serves an entirely different purpose (namely writing of .dat type files). Don't forget to specify the same charset in the way how you've set your Content-Length header.

Second, the parameter names/values themselves should be URL-encoded in order to be extracted properly form the HTTP request.

String urlParameters = "t=" + URLEncoder.encode("выыававыавыавыавфыа", "UTF-8")
                     + "&l=" + URLEncoder.encode("a", "UTF-8");

Third, your request headers are actually also wrong:

connection.setRequestProperty("Content-Type", "text/html"); 
connection.setRequestProperty("charset", "utf-8");

You aren't sending text/html data at all. You are sending application/x-www-form-urlencoded data. Also, that charset should have been an attribute of the Content-Type header, thus so:

connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded;charset=UTF-8");

See also:

Upvotes: 8

Related Questions