Java HttpURLConnection failed to connect to ASP.NET API, connection refused - java

I am trying to use below code to post some data in Java (In Android Studio):
public static String downloadContent(URL url, ContentValues dataToPost) throws IOException {
InputStream is = null;
int length = 500;
String contentAsString = "";
try {
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(10000 /* milliseconds */);
conn.setConnectTimeout(15000 /* milliseconds */);
conn.setRequestMethod("GET");
conn.setDoInput(true);
String queryString = getQuery(dataToPost);
conn.connect();
OutputStream os = conn.getOutputStream();
int response = conn.getResponseCode();
BufferedWriter writer = new BufferedWriter(
new OutputStreamWriter(os, "UTF-8"));
writer.write(queryString);
writer.flush();
writer.close();
is = conn.getInputStream();
contentAsString = convertInputStreamToString(is, length);
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ProtocolException e) {
e.printStackTrace();
e.printStackTrace();
} catch (IOException e) {
String k = e.getMessage();
} finally {
if (is != null) {
is.close();
}
}
return contentAsString;
}
private static String getQuery(ContentValues params) throws UnsupportedEncodingException {
StringBuilder result = new StringBuilder();
boolean first = true;
for (String key : params.keySet()) {
if (first)
first = false;
else
result.append("&");
result.append(URLEncoder.encode(key, "UTF-8"));
result.append("=");
result.append(URLEncoder.encode(params.get(key).toString(), "UTF-8"));
}
return result.toString();
}
public static String convertInputStreamToString(InputStream stream, int length) throws IOException, UnsupportedEncodingException {
Reader reader = null;
reader = new InputStreamReader(stream, "UTF-8");
char[] buffer = new char[length];
reader.read(buffer);
return new String(buffer);
}
And I'm calling the downloadContent method using below code:
URL u = new URL("http://localhost:59524/api/Test/AAA?id=1");
ContentValues c = new ContentValues();
c.put("id", "1");
NetworkCommunication.downloadContent(u, c);
I've also tried changing the URL to http://localhost:59524/api/Test/AAA
And I made an asp.net MVC API using C# (In visual studio) for testing, and here's the code for the API:
public class TestController : ApiController
{
[AcceptVerbs("GET", "POST")]
public IHttpActionResult AAA(int id)
{
return Ok("Very good!");
}
}
I am able to access the API through the browser:
But why in android studio, the program failed to connect?
java.net.ConnectException: failed to connection to localhost/127.0.0.1
(port 59524) after 15000ms: ECONNREFUSED (Connection refused)
The above IOException throws in conn.connect();
Expected result:
When I post the "ID" to http://localhost:59524/api/Test/AAA, I
should receive a string "Very good!"

use Soap webservice to call the asp.net web service.
My WebSrevice.java class code
import org.ksoap2.SoapEnvelope;
import org.ksoap2.serialization.PropertyInfo;
import org.ksoap2.serialization.SoapObject;
import org.ksoap2.serialization.SoapPrimitive;
import org.ksoap2.serialization.SoapSerializationEnvelope;
import org.ksoap2.transport.HttpTransportSE;
import android.R.array;
import android.util.Log;
public class WebService {
//Namespace of the Webservice - can be found in WSDL
private static String NAMESPACE = "http://tempuri.org/";
//Webservice URL - WSDL File location
private static String URL = "webservice path";
//Make sure you changed IP address
//SOAP Action URI again Namespace + Web method name
private static String SOAP_ACTION = "http://tempuri.org/";
public static String invokeCategory( String webMethName, String compId) {
String loginStatus = "";
// Create request
SoapObject request = new SoapObject(NAMESPACE, webMethName);
// Property which holds input parameters
PropertyInfo compidPI = new PropertyInfo();
// Set Username
compidPI.setName("companyid");
// Set Value
compidPI.setValue(compId);
// Set dataType
compidPI.setType(String.class);
// Add the property to request object
request.addProperty(compidPI);
SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(
SoapEnvelope.VER11);
envelope.dotNet = true;
// Set output SOAP object
envelope.setOutputSoapObject(request);
// Create HTTP call object
HttpTransportSE androidHttpTransport = new HttpTransportSE(URL);
try {
// Invoke web service
androidHttpTransport.call(SOAP_ACTION+webMethName, envelope);
// Get the response
SoapPrimitive response = (SoapPrimitive) envelope.getResponse();
// Assign it to boolean variable variable
loginStatus = response.toString();
} catch (Exception e) {
//Assign Error Status true in static variable 'errored'
Login.errored = true;
e.printStackTrace();
}
//Return booleam to calling object
return loginStatus;
}
}
My asynchtask class
private class GetCategoryAndProduct extends AsyncTask<String,Void,Void>
{
#Override
protected Void doInBackground(String... params) {
//Call Web Method
data =(WebService.invokeCategory("getCategory",company_id,"0"));
return null;
}
#Override
//Once WebService returns response
protected void onPostExecute(Void result) {
//get server response here
}
}
}
#Override
protected void onPreExecute() {
}
}
My Asp.net webservice code
[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
public class Login_Service : System.Web.Services.WebService
{
[WebMethod]
public string getCategory(string companyid)
{
//write your web service code here
}
}
feel free to comment here

Related

How to add basic auth java android in AsyncTask or RequestHandler.java?

My question is how to add basic auth Java Android AsyncTask? Some of developers said it needs to be declared in RequestHandler.java or in doInBackground AsyncTask function. Below is my code:
private void loginTask(String _username, String _password){
final String username = _username;
final String password = _password;
class LoginTask extends AsyncTask<Void,Void,String> {
ProgressDialog loading;
#Override
protected void onPreExecute() {
super.onPreExecute();
loading = ProgressDialog.show(LoginActivity.this,"Fetching...","Wait...",false,false);
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
loading.dismiss();
}
#Override
protected String doInBackground(Void... params) {
RequestHandler rh = new RequestHandler();
String s = rh.sendGetRequest(App.URL_AUTHENTICATION);
Toast.makeText(LoginActivity.this, s.toString(), Toast.LENGTH_SHORT).show();
return s;
}
}
LoginTask gt = new LoginTask();
gt.execute();
}
RequestHandler class: https://github.com/IntellijSys/AndroidToDoList/blob/master/app/src/main/java/my/intellij/androidtodolist/RequestHandler.java
Try this
RequestHandler rh = new RequestHandler();
// your basic auth username and password
rh.setBasicAuth("username","password");
String s = rh.sendGetRequest(App.URL_AUTHENTICATION);
RequestHandler class with Basic auth
import android.util.Base64;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;
import javax.net.ssl.HttpsURLConnection;
/**
* Created by ZERO on 16/08/2016.
*/
public class RequestHandler {
private String username;
private String password;
//Method to send httpPostRequest
//This method is taking two arguments
//First argument is the URL of the script to which we will send the request
//Other is an HashMap with name value pairs containing the data to be send with the request
public String sendPostRequest(String requestURL,
HashMap<String, String> postDataParams) {
URL url;
//StringBuilder object to store the message retrieved from the server
StringBuilder sb = new StringBuilder();
try {
//Initializing Url
url = new URL(requestURL);
//Creating an httmlurl connection
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
//set Basic auth
processBasicAuth(conn);
//Configuring connection properties
conn.setReadTimeout(15000);
conn.setConnectTimeout(15000);
conn.setRequestMethod("POST");
conn.setDoInput(true);
conn.setDoOutput(true);
//Creating an output stream
OutputStream os = conn.getOutputStream();
//Writing parameters to the request
//We are using a method getPostDataString which is defined below
BufferedWriter writer = new BufferedWriter(
new OutputStreamWriter(os, "UTF-8"));
writer.write(getPostDataString(postDataParams));
writer.flush();
writer.close();
os.close();
int responseCode = conn.getResponseCode();
if (responseCode == HttpsURLConnection.HTTP_OK) {
BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
sb = new StringBuilder();
String response;
//Reading server response
while ((response = br.readLine()) != null) {
sb.append(response);
}
}
} catch (Exception e) {
e.printStackTrace();
}
return sb.toString();
}
private void processBasicAuth(HttpURLConnection conn) {
if (username != null && password != null) {
try {
String userPassword = username + ":" + password;
byte[] data = userPassword.getBytes("UTF-8");
String base64 = Base64.encodeToString(data, Base64.DEFAULT);
conn.setRequestProperty("Authorization", "Basic " + base64);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
}
}
public String sendGetRequest(String requestURL) {
StringBuilder sb = new StringBuilder();
try {
URL url = new URL(requestURL);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
//set Basic auth
processBasicAuth(con);
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(con.getInputStream()));
String s;
while ((s = bufferedReader.readLine()) != null) {
sb.append(s + "\n");
}
} catch (Exception e) {
}
return sb.toString();
}
public String sendGetRequestParam(String requestURL, String id) {
StringBuilder sb = new StringBuilder();
try {
URL url = new URL(requestURL + id);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(con.getInputStream()));
String s;
while ((s = bufferedReader.readLine()) != null) {
sb.append(s + "\n");
}
} catch (Exception e) {
}
return sb.toString();
}
private String getPostDataString(HashMap<String, String> params) throws UnsupportedEncodingException {
StringBuilder result = new StringBuilder();
boolean first = true;
for (Map.Entry<String, String> entry : params.entrySet()) {
if (first)
first = false;
else
result.append("&");
result.append(URLEncoder.encode(entry.getKey(), "UTF-8"));
result.append("=");
result.append(URLEncoder.encode(entry.getValue(), "UTF-8"));
}
return result.toString();
}
public void setBasicAuth(String username, String password) {
this.username = username;
this.password = password;
}
}

Sending HTTPS post request in android using HTTPClient for unverified certificates

I have written this piece of code for sending the POST request to a localhost server running nodejs having a certificate generated using openssl command. But when I am trying to send the post request, I can see in android log the issue with the trust anchor and POST request on https is not working but is working if I remove the certificate from nodejs server and send request with http. I know this is because my certificate is not verified from any well known CA like verisign. So, how can I send the request to this https server? I also tried installing the certificate in my android phone but it didn't solved my problem either. I can post the source code of HttpClient.java as well.
public class MainActivity extends AppCompatActivity {
Button encAndSendBtn;
TextView companyName, modelNumber, specification;
public MainActivity() throws MalformedURLException {
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
encAndSendBtn = (Button) findViewById(R.id.encAndSend);
companyName = (TextView) findViewById(R.id.company);
modelNumber = (TextView) findViewById(R.id.modNum);
specification = (TextView) findViewById(R.id.spec);
}
public void onclickbutton(View view) {
encSend scv = new encSend();
scv.execute();
}
private class encSend extends AsyncTask {
String companyNameS = companyName.getText().toString();
String modelNumberS = modelNumber.getText().toString();
String specificationS = specification.getText().toString();
#Override
protected Object doInBackground(Object[] objects) {
JSONObject jsonObjSend = new JSONObject();
JSONObject encrptObjSend = new JSONObject();
try {
jsonObjSend.put("Company", companyNameS);
jsonObjSend.put("Model Number", modelNumberS);
jsonObjSend.put("Specification", specificationS);
String finalData = jsonObjSend.toString();
Log.i("data", finalData);
String key = "HelloWorld321#!";
String encrypt;
try {
CryptLib cryptLib = new CryptLib();
String iv = "1234123412341234";
encrypt = cryptLib.encryptSimple(finalData, key, iv);
encrptObjSend.put("encrptedtext", encrypt);
} catch (Exception e) {
e.printStackTrace();
}
Log.i("Encrypted data", encrptObjSend.toString());
JSONObject header = new JSONObject();
header.put("deviceType", "Android"); // Device type
header.put("deviceVersion", "2.0"); // Device OS version
header.put("language", "es-es"); // Language of the Android client
encrptObjSend.put("header", header);
} catch (JSONException e) {
e.printStackTrace();
}
JSONObject jsonObjRecv = HttpClient.SendHttpPost("https://192.168.43.59:443/api/aes", encrptObjSend);
return "success";
}
}
}
Update:
public class HttpClient {
private static final String TAG = "HttpClient";
public static JSONObject SendHttpPost(String URL, JSONObject jsonObjSend) {
try {
DefaultHttpClient httpclient = new DefaultHttpClient();
HttpPost httpPostRequest = new HttpPost(URL);
StringEntity se;
se = new StringEntity(jsonObjSend.toString());
// Set HTTP parameters
httpPostRequest.setEntity(se);
httpPostRequest.setHeader("Accept", "application/json");
httpPostRequest.setHeader("Content-type", "application/json");
httpPostRequest.setHeader("Accept-Encoding", "gzip"); // only set this parameter if you would like to use gzip compression
long t = System.currentTimeMillis();
HttpResponse response = (HttpResponse) httpclient.execute(httpPostRequest);
Log.i(TAG, "HTTPResponse received in [" + (System.currentTimeMillis()-t) + "ms]");
// Get hold of the response entity (-> the data):
HttpEntity entity = response.getEntity();
if (entity != null) {
// Read the content stream
InputStream instream = entity.getContent();
Header contentEncoding = response.getFirstHeader("Content-Encoding");
if (contentEncoding != null && contentEncoding.getValue().equalsIgnoreCase("gzip")) {
instream = new GZIPInputStream(instream);
}
// convert content stream to a String
String resultString= convertStreamToString(instream);
instream.close();
resultString = resultString.substring(1,resultString.length()-1); // remove wrapping "[" and "]"
// Transform the String into a JSONObject
JSONObject jsonObjRecv = new JSONObject(resultString);
// Raw DEBUG output of our received JSON object:
Log.i(TAG,"<JSONObject>\n"+jsonObjRecv.toString()+"\n</JSONObject>");
return jsonObjRecv;
}
}
catch (Exception e)
{
// More about HTTP exception handling in another tutorial.
// For now we just print the stack trace.
e.printStackTrace();
}
return null;
}
private static String convertStreamToString(InputStream is) {
/*
* To convert the InputStream to String we use the BufferedReader.readLine()
* method. We iterate until the BufferedReader return null which means
* there's no more data to read. Each line will appended to a StringBuilder
* and returned as String.
*
* (c) public domain: http://senior.ceng.metu.edu.tr/2009/praeda/2009/01/11/a-simple-restful-client-at-android/
*/
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
StringBuilder sb = new StringBuilder();
String line = null;
try {
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return sb.toString();
}
}
You should use an always-ok delegate to avoid server certificate validation. Of course you must use https connection. Check this link, for example: http://www.nakov.com/blog/2009/07/16/disable-certificate-validation-in-java-ssl-connections/

How can i connect to my MySQL database with an android app?

i am trying to do an android app to write some datas on MySQL database but it does not work i did a Java class for this and i think the problem comes from this. Here is my code :
public class BackgroundTask extends AsyncTask<String, Void, String> {
Context ctx;
BackgroundTask(Context ctx) {this.ctx = ctx;}
#Override
protected String doInBackground(String... params) {
String reg_url = "http://localhost:8080/project/register.php";
String method = params[0];
if (method.equals("register")) {
String name = params[1];
String password = params[2];
String contact = params[3];
String country = params[4];
try {
URL url = new URL(reg_url);
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setDoOutput(true);
OutputStream os = httpURLConnection.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));
String data = URLEncoder.encode("name", "UTF-8") + "=" + URLEncoder.encode(name, "UTF-8") + "&" +
URLEncoder.encode("password", "UTF-8") + "=" + URLEncoder.encode(password, "UTF-8") + "&" +
URLEncoder.encode("contact", "UTF-8") + "=" + URLEncoder.encode(contact, "UTF-8") + "&" +
URLEncoder.encode("country", "UTF-8") + "=" + URLEncoder.encode(country, "UTF-8");
bufferedWriter.write(data);
bufferedWriter.flush();
bufferedWriter.close();
os.close();
InputStream IS = httpURLConnection.getInputStream();
IS.close();
return "Registration success";
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
#Override
protected void onPostExecute(String result) {
Toast.makeText(ctx, result, Toast.LENGTH_LONG).show();
}
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected void onProgressUpdate(Void... values) {
super.onProgressUpdate(values);
}
}
Actually what i would like is to save name, password, contact and country in my database. The problem is this : "Registration success" is never returned it is always null. But i don't know why. When i try to compile it looks like there is no errors and i can see the app.
Thank you very much for your help !
Edit : This is the register.php :
<?php
require "init.php";
$u_name=$_POST["name"];
$u_password=$_POST["password"];
$u_contact=$_POST["contact"]";
$u_country=$_POST["country"];
$sql_query="insert into users values('$u_name', '$u_password', '$u_contact', '$u_country');";
//mysqli_query($connection, $sql_query));
if(mysqli_query($connection,$sql_query))
{
//echo "data inserted";
}
else{
//echo "error";
}
?>
And also the init.php :
<?php
$db_name = "project";
$mysql_user = "root";
$server_name = "localhost";
$connection = mysqli_connect($server_name, $mysql_user, "", $db_name);
if(!$connection){
echo "Connection not successful";
}
else{
echo "Connection successful";
}
?>
Thank you for your help !
My class PutUtility for getData(), PostData, DeleteData(). you just need to change package name
package fourever.amaze.mics;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;
public class PutUtility {
private Map<String, String> params = new HashMap<>();
private static HttpURLConnection httpConnection;
private static BufferedReader reader;
private static String Content;
private StringBuffer sb1;
private StringBuffer response;
public void setParams(Map<String, String> params) {
this.params = params;
}
public void setParam(String key, String value) {
params.put(key, value);
}
public String getData(String Url) {
StringBuilder sb = new StringBuilder();
try {
// Defined URL where to send data
URL url = new URL(Url);
URLConnection conn = null;
conn = url.openConnection();
// Send POST data request
httpConnection = (HttpURLConnection) conn;
httpConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
httpConnection.setRequestMethod("GET");
BufferedReader in = new BufferedReader(
new InputStreamReader(httpConnection.getInputStream()));
String inputLine;
response = new StringBuffer();
while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
reader.close();
} catch (Exception ex) { }
}
return response.toString();
}
public String postData(String Url) {
StringBuilder sb = new StringBuilder();
for (String key : params.keySet()) {
String value = null;
value = params.get(key);
if (sb.length() > 0) {
sb.append("&");
}
sb.append(key + "=" + value);
}
try {
// Defined URL where to send data
URL url = new URL(Url);
URLConnection conn = null;
conn = url.openConnection();
// Send POST data request
httpConnection = (HttpURLConnection) conn;
httpConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
httpConnection.setRequestMethod("POST");
httpConnection.setDoInput(true);
httpConnection.setDoOutput(true);
OutputStreamWriter wr = null;
wr = new OutputStreamWriter(conn.getOutputStream());
wr.write(sb.toString());
wr.flush();
BufferedReader in = new BufferedReader(
new InputStreamReader(httpConnection.getInputStream()));
String inputLine;
response = new StringBuffer();
while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
reader.close();
} catch (Exception ex) {
}
}
return response.toString();
}
public String putData(String Url) {
StringBuilder sb = new StringBuilder();
for (String key : params.keySet()) {
String value = null;
try {
value = URLEncoder.encode(params.get(key), "UTF-8");
if (value.contains("+"))
value = value.replace("+", "%20");
//return sb.toString();
// Get the server response
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
if (sb.length() > 0) {
sb.append("&");
}
sb.append(key + "=" + value);
}
try {
// Defined URL where to send data
URL url = new URL(Url);
URLConnection conn = null;
conn = url.openConnection();
// Send PUT data request
httpConnection = (HttpURLConnection) conn;
httpConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
httpConnection.setRequestMethod("PUT");
httpConnection.setDoInput(true);
httpConnection.setDoOutput(false);
OutputStreamWriter wr = null;
wr = new OutputStreamWriter(conn.getOutputStream());
wr.write(sb.toString());
wr.flush();
reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
;
String line = null;
// Read Server Response
while ((line = reader.readLine()) != null) {
// Append server response in string
sb1.append(line + " ");
}
// Append Server Response To Content String
Content = sb.toString();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
reader.close();
} catch (Exception ex) {
}
}
// Send PUT data request
return Url;
}
public String deleteData(String Url) {
StringBuilder sb = new StringBuilder();
for (String key : params.keySet()) {
try {
// Defined URL where to send data
URL url = new URL(Url);
URLConnection conn = null;
conn = url.openConnection();
// Send POST data request
httpConnection = (HttpURLConnection) conn;
httpConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
httpConnection.setRequestMethod("DELETE");
httpConnection.connect();
reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String line = null;
// Read Server Response
while ((line = reader.readLine()) != null) {
// Append server response in string
sb1.append(line + " ");
}
// Append Server Response To Content String
Content = sb.toString();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
reader.close();
} catch (Exception ex) {
}
}
}
return Url;
}
}
And use this class like this
#Override
protected String doInBackground(String... params) {
res = null;
PutUtility put = new PutUtility();
put.setParam("ueid", params[0]);
put.setParam("firm_no", params[1]);
put.setParam("date_incorporation", params[2]);
put.setParam("business_name", params[3]);
put.setParam("block_no", params[4]);
try {
res = put.postData(
"Api URL here");
Log.v("res", res);
} catch (Exception objEx) {
objEx.printStackTrace();
}
return res;
}
#Override
protected void onPostExecute(String res) {
try {
} catch (Exception objEx) {
mProgressDialog.dismiss();
objEx.printStackTrace();
}
}
Please use this. Hope it helps you in future also.
Check this if this is the problem
$u_contact=$_POST["contact"]"
here is the problem i think so brother. replace with
$u_contact=$_POST["contact"];

Invoking servlet from java main method

import java.net.*;
import java.io.*;
public class sample
{
public static void main (String args[])
{
String line;
try
{
URL url = new URL( "http://localhost:8080/WeighPro/CommPortSample" );
BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
line = in.readLine();
System.out.println( line );
in.close();
}
catch (Exception e)
{
System.out.println("Hello Project::"+e.getMessage());
}
}
}
My Servlet is invoking another Jsp page like the below,
RequestDispatcher rd=request.getRequestDispatcher("index.jsp");
rd.forward(request, response);
I am not getting any reaction/output in the browser, where the servlet has to be executed once it is invoked.
Am I missing any basic step for this process? Please Help!!!
If you want to open it in browser try this
java.awt.Desktop.getDesktop().browse(java.net.URI.create("http://localhost:8080/WeighPro/CommPortSample"));
You question is not clear. Do you actually want to invoke a Servlet from the Main method, or do you want to make an HTTP request to your web application?
If you want to make an HTTP request, I can't see any obvious problems with your code above, which makes me believe that the problem is in the Servlet. You also mention that you don't get anything in the browser, but running your program above does not involve a browser.
Do you mean that you don't get a response when you go to
http://localhost:8080/WeighPro/CommPortSample
in a browser?
As Suresh says, you cannot call a Servlet directly from a main method.
Your Servlet should instead call methods on other classes, and those other classes should be callable from the main method, or from Test Cases. You need to architect your application to make that possible.
import java.io.BufferedInputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
public class OutBoundSimul {
public static void main(String[] args) {
sendReq();
}
public static void sendReq() {
String urlString = "http://ip:port/applicationname/servletname";
String respXml = text;
URL url = null;
HttpURLConnection urlConnection = null;
OutputStreamWriter out = null;
BufferedInputStream inputStream = null;
try {
System.out.println("URL:"+urlString);
url = new URL(urlString);
urlConnection = (HttpURLConnection)url.openConnection();
urlConnection.setDoInput(true);
urlConnection.setDoOutput(true);
urlConnection.setRequestMethod("POST");
System.out.println("SendindData");
out = new OutputStreamWriter(urlConnection.getOutputStream());
System.out.println("Out:"+out);
out.write(respXml);
out.flush();
inputStream = new BufferedInputStream(urlConnection.getInputStream());
int character = -1;
StringBuffer sb = new StringBuffer();
while ((character = inputStream.read()) != -1) {
sb.append((char) character);
}
System.out.println("Resp:"+sb.toString());
} catch (Exception e) {
e.printStackTrace();
}
}
}
Invoking Servlet with query parameters Form Main method
Java IO
public static String accessResource_JAVA_IO(String httpMethod, String targetURL, String urlParameters) {
HttpURLConnection con = null;
BufferedReader responseStream = null;
try {
if (httpMethod.equalsIgnoreCase("GET")) {
URL url = new URL( targetURL+"?"+urlParameters );
responseStream = new BufferedReader(new InputStreamReader( url.openStream() ));
}else if (httpMethod.equalsIgnoreCase("POST")) {
con = (HttpURLConnection) new URL(targetURL).openConnection();
// inform the connection that we will send output and accept input
con.setDoInput(true); con.setDoOutput(true); con.setRequestMethod("POST");
con.setUseCaches(false); // Don't use a cached version of URL connection.
con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
con.setRequestProperty("Content-Length", Integer.toString(urlParameters.getBytes().length));
con.setRequestProperty("Content-Language", "en-US");
DataOutputStream requestStream = new DataOutputStream ( con.getOutputStream() );
requestStream.writeBytes(urlParameters);
requestStream.close();
responseStream = new BufferedReader(new InputStreamReader( con.getInputStream(), "UTF-8" ));
}
StringBuilder response = new StringBuilder(); // or StringBuffer if not Java 5+
String line;
while((line = responseStream.readLine()) != null) {
response.append(line).append('\r');
}
responseStream.close();
return response.toString();
} catch (Exception e) {
e.printStackTrace(); return null;
} finally {
if(con != null) con.disconnect();
}
}
Apache Commons using commons-~.jar
{httpclient, logging}
public static String accessResource_Appache_commons(String url){
String response_String = null;
HttpClient client = new HttpClient();
GetMethod method = new GetMethod( url );
// PostMethod method = new PostMethod( url );
method.setRequestHeader("Content-type", "text/xml; charset=ISO-8859-1");
method.setQueryString(new NameValuePair[] {
new NameValuePair("param1","value1"),
new NameValuePair("param2","value2")
}); //The pairs are encoded as UTF-8 characters.
try{
int statusCode = client.executeMethod(method);
System.out.println("Status Code = "+statusCode);
//Get data as a String OR BYTE array method.getResponseBody()
response_String = method.getResponseBodyAsString();
method.releaseConnection();
} catch(IOException e) {
e.printStackTrace();
}
return response_String;
}
Apache using httpclient.jar
public static String accessResource_Appache(String url) throws ClientProtocolException, IOException{
try {
CloseableHttpClient httpclient = HttpClients.createDefault();
URIBuilder builder = new URIBuilder( url )
.addParameter("param1", "appache1")
.addParameter("param2", "appache2");
HttpGet method = new HttpGet( builder.build() );
// HttpPost method = new HttpPost( builder.build() );
// Create a custom response handler
ResponseHandler<String> responseHandler = new ResponseHandler<String>() {
#Override
public String handleResponse( final HttpResponse response) throws IOException {
int status = response.getStatusLine().getStatusCode();
if (status >= 200 && status < 300) {
HttpEntity entity = response.getEntity();
return entity != null ? EntityUtils.toString(entity) : null;
}
return "";
}
};
return httpclient.execute( method, responseHandler );
} catch (URISyntaxException e) {
e.printStackTrace();
}
return null;
}
JERSY using JARS {client, core, server}
public static String accessResource_JERSY( String url ){
ClientConfig config = new DefaultClientConfig();
Client client = Client.create(config);
WebResource service = client.resource( url );
ClientResponse response = service.accept(MediaType.TEXT_PLAIN).get(ClientResponse.class);
if (response.getStatus() != 200) {
System.out.println("GET request failed >> "+ response.getStatus());
}else{
String str = response.getEntity(String.class);
if(str != null && !str.equalsIgnoreCase("null") && !"".equals(str)){
return str;
}
}
return "";
}
Java Main method
public static void main(String[] args) throws IOException {
String targetURL = "http://localhost:8080/ServletApplication/sample";
String urlParameters = "param1=value11&param2=value12";
String response = "";
// java.awt.Desktop.getDesktop().browse(java.net.URI.create( targetURL+"?"+urlParameters ));
// response = accessResource_JAVA_IO( "POST", targetURL, urlParameters );
// response = accessResource_Appache_commons( targetURL );
// response = accessResource_Appache( targetURL );
response = accessResource_JERSY( targetURL+"?"+urlParameters );
System.out.println("Response:"+response);
}
Simply you cannot do that.
A response and request pair will generated by web container. You cannot generate a response object and send to the browser.
By the way which client/browser you are expecting to get the response ? No idea. Right ?
When container receives a request from client then it generates response object and serves you can access that response in service method.
If you want to see/test the response, you have to request from there.

Communicate between android Application and java

Every body i am new in program world , I am getting a issue,My Request is related to Communication between Android tablet to Desktop PC using JAVA Code.
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class HelloWorldServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public HelloWorldServlet() {
super();
}
protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
PrintWriter out = response.getWriter();
out.println("Hello Android !!!!");
}
}
above code is my servlet code which is running in my local system server (Tomcat 6.0 ) here i am sending message through println and i want to reveive same message in my Android app which is running in another system. Now i am going to post my android code which is running on another system.
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
public class HttpGetServletActivity3 extends Activity implements
OnClickListener {
Button button;
TextView outputText;
public static final String URL =
"http://192.168.0.2:9999/HttpGetServlet/HelloWorldServlet";
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
findViewsById();
button.setOnClickListener(this);
}
private void findViewsById() {
button = (Button) findViewById(R.id.button);
outputText = (TextView) findViewById(R.id.outputTxt);
}
public void onClick(View view) {
GetXMLTask task = new GetXMLTask();
task.execute(new String[] { URL });
}
private class GetXMLTask extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String... urls) {
String output = null;
for (String url : urls) {
output = getOutputFromUrl(url);
}
return output;
}
private String getOutputFromUrl(String url) {
StringBuffer output = new StringBuffer("");
try {
InputStream stream = getHttpConnection(url);
BufferedReader buffer = new BufferedReader(
new InputStreamReader(stream));
String s = "";
while ((s = buffer.readLine()) != null)
output.append(s);
} catch (IOException e1) {
e1.printStackTrace();
}
return output.toString();
}
// Makes HttpURLConnection and returns InputStream
private InputStream getHttpConnection(String urlString)
throws IOException {
InputStream stream = null;
URL url = new URL(urlString);
URLConnection connection = url.openConnection();
try {
HttpURLConnection httpConnection = (HttpURLConnection) connection;
httpConnection.setRequestMethod("GET");
httpConnection.connect();
if (httpConnection.getResponseCode() == HttpURLConnection.HTTP_OK) {
stream = httpConnection.getInputStream();
}
} catch (Exception ex) {
ex.printStackTrace();
}
return stream;
}
#Override
protected void onPostExecute(String output) {
outputText.setText(output);
}
}}
Here 192.68.0.2 is ip address of system where servlet code is running in my local system (Tomcat6.0 server which has port no 9999) .But it is not working for me.Both the system are in same wifi network Any help is really very appreciated. Thanks in advance to all
try this i will work for you. This is android code
protected Integer doInBackground(String... arg0) {
/** According with the new StrictGuard policy, running long tasks on the Main UI thread is not possible
So creating new thread to create and execute http operations */
new Thread(new Runnable() {
#Override
public void run() {
ArrayList<NameValuePair> postParameters = new ArrayList<NameValuePair>();
postParameters.add(new BasicNameValuePair("username",un.getText().toString()));
postParameters.add(new BasicNameValuePair("password",pw.getText().toString()));
String response = null;
try {
response = SimpleHttpClient.executeHttpPost("http://XXX.168.1.X:5555/LoginServlet/loginservlet.do", postParameters);
res = response.toString();
System.out.println("response :"+res);
} catch (Exception e) {
// e.printStackTrace();
errorMsg = e.getMessage();
}
}
}).start();
/** Inside the new thread we cannot update the main thread
So updating the main thread outside the new thread */
try {
}catch (Exception e) {
error.setText(e.getMessage());
// e.printStackTrace();
}
return null;
}
Now this is another class for android
public class SimpleHttpClient {
public static String result="";
/** The time it takes for our client to timeout */
public static final int HTTP_TIMEOUT = 30 * 1000; // milliseconds
/** Single instance of our HttpClient */
private static HttpClient mHttpClient;
/**
* Get our single instance of our HttpClient object.
*
* #return an HttpClient object with connection parameters set
*/
private static HttpClient getHttpClient() {
if (mHttpClient == null) {
mHttpClient = new DefaultHttpClient();
final HttpParams params = mHttpClient.getParams();
HttpConnectionParams.setConnectionTimeout(params, HTTP_TIMEOUT);
HttpConnectionParams.setSoTimeout(params, HTTP_TIMEOUT);
ConnManagerParams.setTimeout(params, HTTP_TIMEOUT);
}
return mHttpClient;
}
/**
* Performs an HTTP Post request to the specified url with the
* specified parameters.
*
* #param url The web address to post the request to
* #param postParameters The parameters to send via the request
* #return The result of the request
* #throws Exception
*/
public static String executeHttpPost(String url, ArrayList<NameValuePair> postParameters) throws Exception {
BufferedReader in = null;
try {
HttpClient client = getHttpClient();
HttpPost request = new HttpPost(url);
UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(postParameters);
request.setEntity(formEntity);
// String str1= request.setEntity(formEntity);
System.out.println("actual request"+formEntity);
HttpResponse response = client.execute(request);
System.out.println("response in class"+response);
in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
StringBuffer sb = new StringBuffer("");
String line = "";
String NL = System.getProperty("line.separator");
while ((line = in.readLine()) != null) {
sb.append(line + NL);
}
in.close();
result = sb.toString();
}catch(Exception e){
e.printStackTrace();
System.out.println("catch");
}
finally {
if (in != null) {
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return result;
}
/**
* Performs an HTTP GET request to the specified url.
*
* #param url The web address to post the request to
* #return The result of the request
* #throws Exception
*/
public static String executeHttpGet(String url) throws Exception {
String result="";
BufferedReader in = null;
try {
HttpClient client = getHttpClient();
HttpGet request = new HttpGet();
request.setURI(new URI(url));
HttpResponse response = client.execute(request);
in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
StringBuffer sb = new StringBuffer("");
String line = "";
String NL = System.getProperty("line.separator");
while ((line = in.readLine()) != null) {
sb.append(line + NL);
}
in.close();
result = sb.toString();
}
catch(Exception e){
e.printStackTrace();
System.out.println("catch2");
}
finally {
if (in != null) {
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return result;
}}
And finally this is servlet code for you
public class LoginServlet extends HttpServlet {
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
String un,pw;
un=request.getParameter("username");
pw=request.getParameter("password");
System.out.println("username :"+un);
System.out.println("password :"+pw);
if(un.equals("") || pw.equals("") ){
out.print("null");
}
else if(un.equalsIgnoreCase("hello") && pw.equals("world"))
{
out.print("success");
}
else{
out.print("failed");
}
System.out.println("after :");
request.getAttribute("USER"+un);
request.getAttribute("PASS"+pw);
RequestDispatcher rd=request.getRequestDispatcher("home.jsp");
rd.forward(request, response);
}catch(Exception e){
System.out.println("inside exception");
e.printStackTrace();
}
finally {
out.close();
}
}
#Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
service(request, response);
}
#Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
service(request, response);
}
#Override
public String getServletInfo() {
return "Short description";
}}

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