Develop Reference

how to save HTML code of a URL in a string in Android

I am trying to get HTML source code from a Url ... I added up permission of INTERNET as well but still I couldnot get the HTML code in string ... my application just crash ... am using this on Android 4.2 ...i have also loaded same page in webview and webview is displaying the page ...Please help me ...
I am using following code
public String getXml(String url) {
try {
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(url);
ResponseHandler<String> resHandler = new BasicResponseHandler();
String page = httpClient.execute(httpGet, resHandler);
return page;
} catch (ClientProtocolException e) {
e.printStackTrace();
return "";
} catch (IOException e) {
e.printStackTrace();
return "";
}
}
I want to ask another question as well
what if I have to get the HTML source code of a webpage which is already downloaded ?

Do what #TGMCians said, and put this in an AsyncTask. But to get the returned HTML in a string, do:
String responseEntity = EntityUtils.toString(page.getEntity);
and that should have your HTML in it.

I think you are doing network operation on main Thread that result to exception.
NetworkOnMainThreadException.
So use AsyncTask to do network operation on android version >= 3.0.
EDIT
To learn about How to perform operation in AsyncTask.
Look Android developer docs.

Android: How to set encoding in JSONStringer for webservice requests?

I finished the English version of my application and I am currently working on my Arabic application version. Although my English webservices were working fine, there seems to be a problem with my Arabic webservices, I feel that I need to specify the encoding type (utf-8) when I construct my JSON request using the JSONStringer class. Is there a way to do that?
Here is an example of a method that constructs my JSON request,
public static String initLoginJSONRequest(String username, String password){
String parentString = null;
String childString = null;
try{
childString = new JSONStringer()
.object()
.key("username").value(username)
.key("password").value(password)
.endObject()
.toString();
parentString = new JSONStringer()
.object()
.key("UserCredentials").value(childString)
.endObject()
.toString();
}catch(JSONException e){
e.printStackTrace();
}
return parentString;
}
EDIT
I would also like to add that I specify that my encoding is utf-8 in my HttpPost as shown below,
HttpPost post = new HttpPost(getUrl);
StringEntity se = new StringEntity(jsonString);
se.setContentType("application/json;charset=UTF-8");//text/plain;charset=UTF-8
se.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE,"application/json;charset=UTF-8"));
post.setEntity(se);
response = client.execute(post);
But it is not recieving my Arabic charecters on the webservice end (written in .NET) correctly.

Try to change UTF-8 by ISO-8859-1
The answers here can help you:
Android - Read an XML file with HTTP GET

Http Post Request in Android won't return appropriate data?

Okay, so I was trying to send Http Post Requests to this one site, and I sniffed the sent request with wireshark thus getting the text data from the post request of this site. I used this in a stock Java application, and it worked perfectly fine. I could use the post method regularly with no problem whatsoever, and it would return the appropriate website. Then I tried doing this with Android. Instead of returning the actual html data after executing the post request, it returns the regular page html data untouched. It DOES send a post request (sniff with wireshark again), it just doesn't seem to get the appropriate response. I took the exact same method used from another one of my projects, which worked perfectly fine in that project, and pasted it into my new project. I added the INTERNET user permission in Android, so there's nothing wrong with that. The only visible difference is that I used NameValuePairs in the other one (the one that worked) and in this one I'm directly putting the string into a StringEntity without encoding (using UTF-8 encoding screws up the String though). I used this exact same line of text in regular Java like I said, and it worked fine with no encoding. So what could be the problem? This is the code:
public static String sendNamePostRequest(String urlString) {
HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost(urlString);
StringBuffer sb = new StringBuffer();
try {
post.setEntity(new StringEntity(
"__EVENTTARGET=&__EVENTARGUMENT=&__VIEWSTATE=%2FwEPDwULLTE3NDM5MzMwMzRkZA%3D%3D&__EVENTVALIDATION=%2FwEWBAL%2B%2B4CfBgK52%2BLYCQK1gpH7BAL0w%2FPHAQ%3D%3D&_nameTextBox=John&_zoekButton=Zoek&numberOfLettersField=3"));
HttpResponse response = client.execute(post);
HttpEntity entity = response.getEntity();
BufferedReader br = new BufferedReader(new InputStreamReader(
entity.getContent()));
String in = "";
while ((in = br.readLine()) != null) {
sb.append(in + "\n");
}
br.close();
} catch (Exception e) {
e.printStackTrace();
}
return sb.toString();
}
Can you see what's wrong here?

Android Jackson JSON Parser null value

I am using the Jackson JSON parser as I heard it was a lot more efficient than the default Android parser. I learned how to use it off this tutorial here
http://www.mkyong.com/java/jackson-streaming-api-to-read-and-write-json/
which is great tutorial if anyone wants to learn how to use Jackson json parser.
However, I am having an issue in that I can parse data fine in Java from a URL, however when I use Jackson with Android, I get null values or the screen just shows up black for some reason.
In order to retrieve the data from the website I am using this code from here
http://www.javacodegeeks.com/2011/01/android-json-parsing-gson-tutorial.html
private InputStream retrieveStream(String url) {
DefaultHttpClient client = new DefaultHttpClient();
HttpGet getRequest = new HttpGet(url);
try {
HttpResponse getResponse = client.execute(getRequest);
final int statusCode = getResponse.getStatusLine().getStatusCode();
if (statusCode != HttpStatus.SC_OK) {
Log.w(getClass().getSimpleName(),
"Error " + statusCode + " for URL " + url);
return null;
}
HttpEntity getResponseEntity = getResponse.getEntity();
return getResponseEntity.getContent();
}
catch (IOException e) {
getRequest.abort();
Log.w(getClass().getSimpleName(), "Error for URL " + url, e);
}
return null;
}
Then in my parse data method
InputStream source = retrieveStream(url);
try {
JsonFactory jfactory = new JsonFactory();
JsonParser jParser = jfactory.createJsonParser(source);
Then I parse data as was shown in the tutorial I linked above
while (jParser.nextToken() != JsonToken.END_OBJECT) {
String fieldname = jParser.getCurrentName();
if ("Name".equals(fieldname)) {
jParser.nextToken();
this.setName(jParser.getText());
}
if ("Number".equals(fieldname)) {
jParser.nextToken();
this.setNumber(jParser.getText());
}
}
The url I am using is a dummy site set up which just has a JSON file on it which I am using to practice Jackson JSON parsing.
Now I know my parse data code is fine, as I in normal Java class, I can parse the data from the website using the code I created, and it works fine.
However if I try to use the code in Android with the code I have just shown, I just get a black screen for some odd reason. I have internet permissions enabled in manifest
Is there something wrong with the http code I have used? If so could someone show me how it should be done? And also why I am getting a black screen, I don't understand why it would show that.
Thanks in advance

Not sure if this is the problem, but your looping construct is unsafe: depending on kind of data you get, it is quite possible that you do not get END_OBJECT as the next token. And at the end of content, nextToken() will return null to indicate end-of-input. So perhaps you get into infinite loop with certain input?

I found the issue, the link was local host which could not be accessed from Emulator. Settings were changed, and can now access link, works perfectly now :D

UTF8 Encoding in Android when invoking REST webservice

I'm invoking a rest WS that returns XML. Some elements have strings include special characters like áãç etc...
When I get the information via browser all of it is shown properly but when invoking it from Android I don't get the proper special characters.
Notice the 'decoded' and 'encoded' variables:
when I use
URLDecoder.decode(result, "UTF-8")
The result stays the same
when I use
URLEncoder.encode(result, "UTF-8") The result changes to what it would be expected (full of %'s symbols and numeric representing symbols and special characters).
Here's the method to call the webservice:
public void updateDatabaseFromWebservice(){
// get data from webservice
Log.i(TAG, "Obtaining categories from webservice");
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet(ConnectionProperties.CATEGORIES_URI);
ResponseHandler<String> handler = new BasicResponseHandler();
String result = "";
String decoded;
String encoded;
try {
result = client.execute(request, handler);
decoded = URLDecoder.decode(result, "UTF-8");
encoded = URLEncoder.encode(result, "UTF-8");
String c = "AS";
} catch (Exception e) {
Log.e(TAG, "An error occurred while obtaining categories", e);
}
client.getConnectionManager().shutdown();
}
Any help would be appreciated

Use this to get xml string, assuming the server encodes data in UTF-8:
HttpResponse response = client.execute(request);
... // probably some other code to check for HTTP response status code
HttpEntity responseEntity = response.getEntity();
String xml = EntityUtils.toString(responseEntity, HTTP.UTF_8);

Uh. URLDecoder and encoder are for encoding and decoding URLs, not XML content. It is used for URL you use when making requests. So code is just... wrong.
But even bigger issue is that you are taking a String, whereas content is really XML which needs to be parsed. And for parser to do proper decoding of UTF-8 (and handling of entities etc), you would be better of getting a byte[] from request, passing that to parser; although asking http client to do decoding may work ok (assuming service correctly indicates encoding used; not all do -- but even if not, XML parsers can figure it out from xml declaration).
So: remove URLDecoder/URLEncoder stuff, parser XML, and extract data you want from XML.