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How do you get content from a HttpResponse in servlet?

I am currently learning to develop android application. I need to parse variables from my android application to the servlet. I use HttpResponse to parse the variables. But i do not know how to accept parameters in servlet.
This is my code in android application.
// Create a new HttpClient and Post Header
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://<ip_address>:8080/GetPhoneNumber/GetPhoneNumberServletServlet");
try {
// Add your data
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("phoneNum", "12345678"));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
// Execute HTTP Post Request
HttpResponse response = httpclient.execute(httppost);
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
} // End of onClick method
May I know what to do at the doPost/doGet in servlet?
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
PrintWriter out = response.getWriter();
out.println("Hello Android !!!!");
}
/**
* #see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}

In your doPost use request.getParameter("phoneNum").

I think the following code could help you.
public class CustomHttpClient
{
public static final int HTTP_TIMEOUT = 30 * 1000;
private static HttpClient mHttpClient;
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;
}
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);
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();
String result = sb.toString();
return result;
}
finally
{
if (in != null)
{
try
{
in.close();
}
catch (IOException e)
{
Log.e("log_tag", "Error converting result "+e.toString());
e.printStackTrace();
}
}
}
}
public static String executeHttpGet(String url) throws Exception
{
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();
String result = sb.toString();
return result;
}
finally
{
if (in != null)
{
try
{
in.close();
}
catch (IOException e)
{
Log.e("log_tag", "Error converting result "+e.toString());
e.printStackTrace();
}
}
}
}
}
Addons:-
Use the JSON Parser class below:-
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
// function get json from url
// by making HTTP POST or GET mehtod
public JSONObject makeHttpRequest(String url, String method,
List<NameValuePair> params) {
// Making HTTP request
try {
// check for request method
if(method == "POST"){
// request method is POST
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}else if(method == "GET"){
// request method is GET
DefaultHttpClient httpClient = new DefaultHttpClient();
String paramString = URLEncodedUtils.format(params, "utf-8");
url += "?" + paramString;
HttpGet httpGet = new HttpGet(url);
HttpResponse httpResponse = httpClient.execute(httpGet);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
Log.d("json data",json.toString());
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}
Now if you want to send anything on the server, say you need to save the username and password on the server using the JSON Parser and PHP use the below code in any thread or in the doInBackground method of Async task.
ArrayList<NameValuePair> Insert = new ArrayList<NameValuePair>();
Insert.add(new BasicNameValuePair("User_Name","<Sting denoting username>"));
Insert.add(new BasicNameValuePair("Password","<Sting denoting Password>));
try
{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://server path/yourphpfile.php");
httppost.setEntity(new UrlEncodedFormEntity(Insert));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
}
catch(Exception e)
{
Log.e("log_tag", "Error in http connection"+e.toString());
}
Now if you need these values back using the get method in JSON Parser, user the following code again in the Thread or doInBackground method of Async task.
public class CountDownTask extends AsyncTask<Void,Void , Void>
{
protected void onPreExecute()
{
count = 0;
S_Store_Id = null; S_Store_Name = null;S_Store_Address = null; S_Store_Phone= null;
Offers = null; Descriptions = null;
}
protected Void doInBackground(Void... params)
{
ArrayList<NameValuePair> postParameters = new ArrayList<NameValuePair>();
postParameters.add(new BasicNameValuePair("User_Name",StringUserName));
String response = null;
try
{
response = CustomHttpClient.executeHttpPost("http://yourserverpath/yourphpfilefor retrivingdata.php",postParameters);
String result = response.toString();
try
{
JSONArray jArray = new JSONArray(result);
JSONObject json_data = jArray.getJSONObject(0);
StringUserName = json_data.getString("User_Name");
StringPassword = json_data.getString("Password");
json_data = jArray.getJSONObject(1);
}
catch(JSONException e)
{
Log.e("log_tag", "Error parsing data "+e.toString());
}
}
catch (Exception e)
{
Log.e("log_tag","Error in http connection!!" + e.toString());
}
return null;
}
Now you can write the logic for inserting and retriving data from the server in your corresponding PHP files and use them for using data from the server. This method works equivalent to HTTP Get and Post methods of HTTP Request and Response.
Hope it can help you.. Thanks...

IOException: Internal Server Error when trying to consume rest service

I want to create a restful web service in java using jersey API and consume it in android application. I got this question on SO but it talks about java client whereas I have android client.
My service looks like this:
#Path("/no")
public class CheckNumber {
#POST
#Produces("application/json")
#Consumes("application/json")
public String getDetails(#PathParam("cNo") String cNo) {
String CardNo="";
try {
JSONObject jsonObj = new JSONObject(cNo);
CardNo=jsonObj.getString("CardNo");
} catch (ParseException e1) {
e1.printStackTrace();
}
//Do something
return "someValue";
}
}
Now comes the client side:
public class MainActivity extends Activity {
JSONObject json = new JSONObject();
String wsdl = "http://192.168.1.105:8080/restdemo/check/no/";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
new RequestTask().execute("1234567890");
}
class RequestTask extends AsyncTask<String, String, String> {
#Override
protected String doInBackground(String... uri) {
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response;
String add = "{\"CardNo\":\"" + uri[0] + "\"}";
HttpPost postMethod = new HttpPost(wsdl);
String responseString = null;
try {
postMethod.addHeader("Content-Type", "application/json");
HttpEntity entity = new StringEntity(add);
postMethod.setEntity(entity);
response = httpclient.execute(postMethod);
StatusLine statusLine = response.getStatusLine();
if (statusLine.getStatusCode() == HttpStatus.SC_OK) {
ByteArrayOutputStream out = new ByteArrayOutputStream();
response.getEntity().writeTo(out);
out.close();
responseString = out.toString();
} else {
response.getEntity().getContent().close();
throw new IOException(statusLine.getReasonPhrase());
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
return responseString;
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
}
}
}
I'm just starting with rest web services. I successfully created a sample rest service which consumes string and returns string and used this service in android app.
But when I try to pass json string using POST method. It's giving following errorin log:
java.io.IOException: Internal Server Error
at com.example.restclient.MainActivity$RequestTask.doInBackground(MainActivity.java:85)
where MainActivity.java:85 is throw new IOException(statusLine.getReasonPhrase()); which implies that statusLine.getStatusCode() is not returning HttpStatus.SC_OK. Instead it's returning status code = 500.
Any help appreciated.

It will be good to see the server side log to understand better.
Try creating the entity with UTF8 and set the content-type in the string entity rather than in the postMethod
StringEntity stringEntity = new StringEntity(myJsonDocStr, HTTP.UTF_8);
stringEntity.setContentType("application/json");

Try this code, It works for me
Boolean NetworkLostFlag = false;
HttpParams httpParameters = new BasicHttpParams();
int timeoutConnection = 10000;
HttpConnectionParams.setConnectionTimeout(httpParameters,
timeoutConnection);
int timeoutSocket = 12000;
HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket);
HttpClient httpclient = new DefaultHttpClient(httpParameters);
HttpPost httppost = new HttpPost(strUrl");
try {
httppost.setEntity(new UrlEncodedFormEntity(new BasicNameValuePair(arg1, val1), "UTF-8"));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
if (entity != null) {
InputStream instream = entity.getContent();
try {
// do something useful
StringBuffer buffer = new StringBuffer();
byte[] b = new byte[4096];
for (int n; (n = instream.read(b)) != -1;) {
buffer.append(new String(b, 0, n));
}
result = buffer.toString();
} catch (Exception e) {
NetworkLostFlag = true;
// TODO: handle exception
} finally {
instream.close();
}
}
} catch (Exception e) {
NetworkLostFlag = true;
e.printStackTrace();
}

Send key-value parametres and json message body throught http post request

I need to send http POST request from mobile android application to the server side applcation.
This request need to contain json message in body and some key-value parametres.
I am try to write this method:
public static String makePostRequest(String url, String body, BasicHttpParams params) throws ClientProtocolException, IOException {
Logger.i(HttpClientAndroid.class, "Make post request");
HttpPost httpPost = new HttpPost(url);
StringEntity entity = new StringEntity(body);
httpPost.setParams(params);
httpPost.setEntity(entity);
HttpResponse response = getHttpClient().execute(httpPost);
return handleResponse(response);
}
Here i set parametres to request throught method setParams and set json body throught setEntity.
But it isn't work.
Can anybody help to me?

You can use a NameValuePair to do this..........
Below is the code from my project where I used NameValuePair to sent the xml data and receive the xml response, this will provide u some idea about how to use it with JSON.
public String postData(String url, String xmlQuery) {
final String urlStr = url;
final String xmlStr = xmlQuery;
final StringBuilder sb = new StringBuilder();
Thread t1 = new Thread(new Runnable() {
public void run() {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(urlStr);
try {
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(
1);
nameValuePairs.add(new BasicNameValuePair("xml", xmlStr));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
Log.d("Vivek", response.toString());
HttpEntity entity = response.getEntity();
InputStream i = entity.getContent();
Log.d("Vivek", i.toString());
InputStreamReader isr = new InputStreamReader(i);
BufferedReader br = new BufferedReader(isr);
String s = null;
while ((s = br.readLine()) != null) {
Log.d("YumZing", s);
sb.append(s);
}
Log.d("Check Now",sb+"");
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
});
t1.start();
try {
t1.join();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("Getting from Post Data Method "+sb.toString());
return sb.toString();
}

Android, HttpPost for WCF

I'm trying to use httpost to get data from our WCF webservice
If the webservice function is without params , something like List getAllMessages()
I'm getting the List in json, no problem here
The tricky part is when the function needs to get argument
let's say Message getMessage(string id)
when trying to call this kind of functions I get error code 500
The working code is:
public String GetAllTitles()
{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(
"http://www.xxx.com/Service/VsService.svc/GetAllTitles");
httppost.setHeader("Content-Type", "application/json; charset=utf-8");
try {
// Add your data
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
return readHttpResponse(response);
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
this code works great for functios without arguments..
I took this code and changed it to:
public String SearchTitle(final String id)
{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(
"http://www.xxx.com/Service/VsService.svc/SearchTitle");
httppost.setHeader("Content-Type", "application/json; charset=utf-8");
httppost.setHeader("Accept", "application/json; charset=utf-8");
NameValuePair data = new BasicNameValuePair("id",id);
try {
// Add your data
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(data);
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
return readHttpResponse(response);
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
The function header in thr webservice is:
[OperationContract]
public TitleResult SearchTitle(string id)
{
Stopwatch sw = LogHelper.StopwatchInit();
try
{
TitleManager tm = new TitleManager();
Title title = tm.TitleById(id);
sw.StopAndLog("SearchTitle", "id: " + id);
return new TitleResult() { Title = title };
}
catch (Exception ex)
{
sw.StopAndLogException("SearchTitle", ex, "id: " + id);
return new TitleResult() { Message = ex.Message };
}
}
Anyone can see what am I missing?
Thanks, I'm breaking my head over this one.

List isn't json,
try
String data = "{ id : \"" + id + "\" }";
Don't forget to set Content-Length to data.length.

Not getting JSON value in Spring Controller method

I need to send some data from my Android device to my server. I am doing this through JSON. I have implemented the JSON post on Android, and I am trying to do a mapping on the server side in order to retrieve that data. My problem is that I keep getting an empty string.
Android method used to send JSON:
private void sendJson(final String json, final String URL) {
Thread t = new Thread(){
public void run() {
Looper.prepare(); //For Preparing Message Pool for the child Thread
HttpClient client = new DefaultHttpClient();
HttpConnectionParams.setConnectionTimeout(client.getParams(), 10000); //Timeout Limit
try{
HttpPost post = new HttpPost(URL);
StringEntity se = new StringEntity(json);
se.setContentType(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));
post.setEntity(se);
client.execute(post);
}
catch(Exception e){
e.printStackTrace();
}
Looper.loop(); //Loop in the message queue
}
};
t.start();
}
Server-side method:
#RequestMapping(value = "/getLatestCalls", method = RequestMethod.POST)
public void getData(#ModelAttribute String json){
//... do something
}
The thing is that in this method my json String is "" every time. I have also tried using #RequestParam but with that it doesn't enter the method anymore. I have also tried with #ModelAttribute("json").
Can someone enlighten me a little here? Thank you in advance.

Here is the solution and it works fine.
server-side
#Controller
public class DataCollector {
#RequestMapping(value = "/clientdatacollector", method = RequestMethod.POST)
public #ResponseBody
void abc(Writer writer, #RequestParam("gpsdata") String gpsJSON) {
try {
// here is your jsonstring ;)
writer.write(gpsJSON.toString());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
client-side
public static void httptest() {
ArrayList<TravellingData> tdArray = new ArrayList<TravellingData>();
Gson gson = new Gson();
String jsonString = "";
for (int i = 0; i < 1; i++) {
tdArray.add(ObjectCreater.createMockTravellingDataObject());
}
jsonString = gson.toJson(tdArray);
HttpClient client = new DefaultHttpClient();
HttpPost post = null;
try {
post = new HttpPost(
"http://localhost:8080/uygulama/clientdatacollector");
} catch (URISyntaxException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
try {
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1);
nameValuePairs.add(new BasicNameValuePair("gpsdata", jsonString));
post.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = null;
try {
response = client.execute(post);
} catch (HttpException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
BufferedReader rd = new BufferedReader(new InputStreamReader(
response.getEntity().getContent()));
String line = "";
while ((line = rd.readLine()) != null) {
System.out.println(line);
}
} catch (IOException e) {
e.printStackTrace();
}
}

Try using #RequestBody. It should work.