currently i am using the following code to interact with server
public String connectToserverforincomingmsgs(String phonurl, String phno)
throws IOException {
URL url = new URL(phonurl);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setDoInput(true);
// Allow Outputs
con.setDoOutput(true);
con.connect();
BufferedWriter writer = null;
writer = new BufferedWriter(new OutputStreamWriter(
con.getOutputStream(), "UTF-8"));
// give server your all parameters and values (replace param1 with you
// param1 name and value with your one's)
writer.write("sender_no=" + phno);
writer.flush();
String responseString = "";
BufferedReader reader = null;
reader = new BufferedReader(new InputStreamReader(con.getInputStream()));
String line;
while ((line = reader.readLine()) != null) {
responseString = responseString.concat(line);
}
con.disconnect();
return responseString;
}
how could i make tcp connection .right now i don't have any idea . i am new to android and java aswell so any sample code about the tcp connection would be appreciated
To create a TCP Connection you need to Use Socket:
Socket socket = new Socket(host_name_or_ip_address, port_no);
To Send Data use socket.getOutputStream()
To Receive Data use socket.getInputStream()
Just replace HttpURLConnection with Socket. It works pretty much the same
Related
I want to send json data via stream to the server, but I struggle to make it work.
I have the following method:
String data = "{\"id\":\"2633\",\"f_name\":\"Test\",\"l_name\":\"Aplikace\",\"city\":\"Nymburk\",\"address\":\"Testovaci 123456789 xyz\",\"psc\":\"288 02\"}";
private String httpPost(String urlString, String data, String session_per) {
StringBuffer sb = new StringBuffer("");
String s1 = "";
try {
URL url = new URL(urlString);
String s2 = "";
HttpURLConnection httpurlconnection = (HttpURLConnection)url.openConnection();
httpurlconnection.setDoInput(true);
httpurlconnection.setDoOutput(true);
httpurlconnection.setUseCaches(false);
httpurlconnection.setRequestMethod("POST");
httpurlconnection.setRequestProperty("Cookie",session_per);
httpurlconnection.setRequestProperty("Authentication-Token", GlobalVar.KLIC);
httpurlconnection.setRequestProperty("Content-type", "application/json");
httpurlconnection.setAllowUserInteraction(false);
OutputStreamWriter outStrWrt = new OutputStreamWriter(httpurlconnection.getOutputStream());
outStrWrt.write(data);
outStrWrt.close();
String s3 = httpurlconnection.getResponseMessage();
//dataoutputstream.flush();
//dataoutputstream.close();
InputStream inputstream = httpurlconnection.getInputStream();
String line = "";
BufferedReader br = new BufferedReader(new InputStreamReader(inputstream));
int i;
while( (line = br.readLine()) != null) {
sb.append(line);
}
s1 = sb.toString();
}
catch(Exception ex)
{
ex.printStackTrace();
s1 = "";
}
return s1;
}
Can anyone tell me why this won't work? The cookies etc. are all correct. Did I miss something important? This is like the 6th method I am trying and I'm starting to get desperate :D
Thank you!
EDIT:
It succesfully connects and the server responds, but it doesn't update user data, as if the json didn't get to the server correctly.
If my Java code is correct there may be a server-side issue.
Try to use flush() method,you don't close this output stream before you read all bytes
outStrWrt.flush();
InputStream inputstream=httpurlconnection.getInputStream();
If you use Java 11, you can try to use HttpClient too.
E.g:
HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder().uri(new URI(urlString)).header("Cookie",session_per).header("Authentication-Token",GlobalVar.KLIC).header("Content-type","application/json").POST(HttpRequest.BodyPublishers.ofString(data)).build();
String datas=client.send(request,BodyHandlers.ofString());
return datas;
I have a node.js which waits for post with 2 parameters (name and pass):
app.post('/login.html', function (req, res) {
log.info(req.body);
userName = req.body.name;
pass = req.body.pass;
...
}
I'm trying to send post with the 2 parameters via simple java application, but I can't see that it arrive to the node.js.
what am I missing ?
The java code:
public static void main(String[] args) {
URL url;
HttpURLConnection urlConnection = null;
try {
url = new URL("http://83.63.118.111:31011/login.html");
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setReadTimeout(10000);
urlConnection.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
urlConnection.setConnectTimeout(10000);
urlConnection.setRequestMethod("POST");
urlConnection.setDoInput(true);
urlConnection.setDoOutput(true);
OutputStream os = urlConnection.getOutputStream();
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));
String str = "name='root'&pass='123456'";
//System.out.print(str);
writer.write(str);
writer.flush();
Thread.sleep(100);
writer.close();
os.close();
}
Your code will close when start send data (send and stop)
You should wait it done.
Add code after writer.flush();
Example get response:
BufferedReader in = new BufferedReader(
new InputStreamReader(urlConnection.getInputStream()));
String inputLine;
StringBuilder response = new StringBuilder();
while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();
or just get responseCode:
int responseCode = urlConnection.getResponseCode();
Your program wait send request success or fail.
I think you use Thread.sleep(100); to wait send request, but it stop your Thread (don't send data to server)
Your code have req.body, Express.js don't have it, need use middleware body-parser.
My program below stopped at the line:
InputStream is = conn.getInputStream();
Neither error message popped up nor any output displayed on the console.
I am running Eclipse Oxygen 4.7.0 on Red Hat Enterprise Linux Server release 7.4.
public static void solveInstance(String instanceName){
// solve a problem instance
try{
String query_url = "http://localhost:8807/scheduler";
// read Request to a JSON Object
JSONParser parser = new JSONParser();
JSONObject request = (JSONObject) parser.parse(new FileReader(instanceName));
// open connection
URL url = new URL(query_url);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setConnectTimeout(5000);
conn.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
conn.setDoOutput(true);
conn.setRequestMethod("POST");
// POST Request
OutputStream os = conn.getOutputStream();
OutputStreamWriter osw = new OutputStreamWriter(os, "UTF-8");
osw.write(request.toString());
osw.close();
// Get Response
InputStream is = conn.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader in = new BufferedReader(isr);
String inputLine;
StringBuffer response = new StringBuffer();
while(( inputLine = in.readLine()) != null )
{
response.append(inputLine);
}
in.close();
// Write response to a file
JSONObject jsonObj = (JSONObject) parser.parse(response.toString());
String responseFile = /path_to_result/result.json;
FileWriter fileWriter = new FileWriter(responseFile);
fileWriter.write(jsonObj.toString());
fileWriter.flush();
fileWriter.close();
System.out.println("Solved" + instanceName);
}
catch(Exception e) {
System.out.println(e);
}
}
I noticed that the similar question is asked InputStream is = httpURLConnection.getInputStream(); stop working
but it was for Android and no solution was given there.
Does anyone have some idea on that? Do not hesitate to point out anything else wrong in my code.
Thanks a lot!
Your server isn't responding.
It would be wise to set a read timeout, with conn.setReadTimeout(5000) (say). Adjust the timeout as necessary.
Check response code
int response = connection.getResponseCode();
If you get 301 it means that your resource is redirected. Try to change URI from http to https.
It helped in my case.
Can Java experts help me on this issue, I'm geting the error below
java.lang.IllegalStateException: Cannot use BufferedReader while ServletInputStream is in use
I'm calling a REST service url to post some data using a server side java code, not through a browser.
try{
String urlLocation = "http://myserver/james/dev/hello.nsf/services.xsp/test";
URL url = new URL(urlLocation);
HttpURLConnection connection = (HttpURLConnection)url.openConnection();
connection.setRequestMethod("POST");
connection.setAllowUserInteraction(false);
connection.setDoOutput(true);
connection.setDoInput(true);
connection.setUseCaches(false);
connection.setRequestProperty( "Content-type", "application/x-www-form-urlencoded" );
//connection.setRequestProperty( "Content-length", Integer.toString(content.length()));
DataOutputStream out = new DataOutputStream (connection.getOutputStream ());
out.writeBytes (getXML());
out.flush ();
out.close ();
connection.disconnect();
in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String line;
while( (line = in.readLine()) !=null) {
System.out.println(line);
}
in.close();
}
catch(Exception e){
System.out.println("Error from 2nd try statement");
e.printStackTrace();
e.toString();
}
Any help will be greatly appreciated...
It seems to be this line
in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
I noticed the BufferedReader is not being instantiated, you are reusing an instance variable in.
I copied your code and just changed it to this, and I can make multiple requests without any problem.
BufferedReader in = new BufferedReader(
new InputStreamReader(connection.getInputStream()));
I am sending json string in an https post request to an apache servert(request sends json data to a cgi-bin script that actually is a python script). Am using a standard cgi call -
f=open("./testfile", "w+")
f.write("usageData json = \n")
<b>form = cgi.FieldStorage()
formList = ['Data']
str = form['Data'].value
str = json.dumps(backupstr)
</b>
print backupstr
to read the json string in the url. Problem is that the script is not reading the json in the url even though the script is getting fired (the basic print statements are executing ...). This is how am sending data from the post side :
HttpsURLConnection connection = null;
try{
connection = (HttpsURLConnection)url.openConnection();
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-Type",
"application/json");
connection.setRequestProperty("Content-Length", "" +
Integer.toString(jsonstring.getBytes().length));
connection.setRequestProperty("Content-Language", "en-US");
connection.setUseCaches (false);
connection.setDoInput(true);
connection.setDoOutput(true);
//Send request
DataOutputStream wr = new DataOutputStream (
connection.getOutputStream ());
//wr.writeBytes(jsonstring);
wr.writeUTF(URLEncoder.encode(jsonstring, "UTF-8"));
wr.flush ();
wr.close ();
//Get Response
InputStream is = connection.getInputStream();
BufferedReader rd = new BufferedReader(new InputStreamReader(is));
String line;
StringBuffer response = new StringBuffer();
while((line = rd.readLine()) != null) {
response.append(line);
}
rd.close();
//response = httpClient.execute(request);
}
catch (Exception e)
{
System.out.println("Exception " + e.getMessage());
throw e;
}
I suspect am missing one or more of the connection.setRequestProperty() settings on the sending end that's why it's firing the script but not reading the json string in the url ...what am I doing wrong ...?