Develop Reference

Problems transforming special characters to bytes and strings

I'm showing a dropdown on a web page but when using characters as ○ as options, the dropdown shows a question mark
I'm getting the dropdown option from a SQL Server database in which the column that saves the value is nvarchar type
Then I create an XML output string with the values to send it as response of an AJAX call
When I do xmlWriter.toString() , being xmlWriter a StringWriter object, I'm able to see the ○ character using Eclipse's debug mode but that string needs to be sent as a ByteArrayOutputStream object to add it to response stream for the response to see the XML file on the client side but when doing xmlWriter.toString().getBytes() the ○ character becomes a question mark
I've tried to use xmlWriter.toString().getBytes("UTF-8") but the result is some strange symbols
What am I missing?

By guessing what might be your problem it feels like you're not specifying the encoding in your response object to the browser and it fails guessing the right one. Consider calling getBytes("UTF-8") as you did (better: getBytes(StandardCharsets.UTF_8)) and submit an encoding information along with your response, either in the HTTP header (Content-Type: application/xml; charset=utf-8) as you're probably using HTTP or in the XML header (<?xml version="1.0" encoding="utf-8"?>). Maybe even both as this will provide you the best compatibility.

How to post a big string/json using AJAX on Play Framework 1.4.x

I have a JSON that looks more or less like this:
{"id":"id","date":"date","csvdata":"csvdata".....}
where csvdata property is a big amount of data in JSON format too.
I was trying to POST this JSON using AJAX in Play! Framework 1.4.x so I sended just like that, but when I receive the data in the server side, the csvdata looks like [object Object] and stores it in my db.
My first thought to solve this was to send the csvdata json in string format to store it like a longtext, but when I try to do this, my request fails with the following error:
413 (Request Entity Too Large)
And Play's console show me this message:
Number of request parameters 3623 is higher than maximum of 1000, aborting. Can be configured using 'http.maxParams'
I also tried to add http.maxParams=5000 in application.conf but the only result is that Play's console says nothing and in my database this field is stored as null.
Can anyone help me, or maybe suggest another solution to my problem?
Thanks you so much in advance.

Is it possible that you sent "csvdata" as an array, not a string? Each element in the array would be a separate parameter. I have sent 100KB strings using AJAX and not run into the http.maxParams limit. You can check the contents of the request body using your browser's developer tools.
If your csvdata originates as a file on the client's machine, then the easiest way to send it is as a File. Your controller action would look like:
public static void upload(String id, Date date, File csv) {
...
}
When Play! binds a parameter to the File type, it writes the contents of the parameter to a temporary file which you can read in. (This avoids running out of memory if a large file is uploaded.) The File parameter type was designed for a normal form submit, but I have used it in AJAX when the browser supported some HTML5 features (File API and Form Data).

Jackson JSON Handling of Unicode symbols

I'm calling a webservice that returns text including the ascii symbols representing the ® symbol. For example:
ACME Corp® Services
I use spring to return this textual data directly as a JSON object, and by the time it gets into the browser the json data remains correct:
"service": "ACME Corp® Services"
But upon being rendered via a Handlebars template and written into the page I get:
ACME Corp® Services
Do I need to sanitize the JSON data before using it? If so, what are the best practices for doing that? Otherwise, perhaps there is a change I should make on the back-end but I am not sure what that would be.

You do not need to sanitize content, but you must make sure it uses valid encoding allowed by JSON specification: typically UTF-8 (alternatives being UTF-16 and UTF-32).
If content is not encoded as UTF-8 but something else (like ISO-8859-1 aka "Latin-1"), you will need to construct Reader to decode it properly:
Reader r = new InputStreamReader(in, StandardCharset.ISO_8859_1);
MyPOJO pojo = mapper.readValue(r, MyPOJO.class);
Problem you seem to be having is that encoding used is incorrect.

Android parse special characters in json response

In my Android application I get JSON response string from a PHP url. from the response I get some hotel names with apostrophe, I get &#039 character instead of apostrophe. How can I parse the hotel with special characters in android? I can see the apostrophe in the browser but could not see in android logcat.
I have tried jresponse = URLEncoder.encode(jresponse,"UTF-8"); but I could not get apostrophe for hotel name.
This is the one of the hotel name in the response.
I see the following in browser.
{"id":12747,
"name":"Oscar's",
....
}
But in the logcat:
id 12747
name Oscar's

Use the decoder instead of encoder. URLDecoder.decode(jresponse,"UTF-8")

Use ISO-8859-2 when you create the URLEncodedEntity that you send off. You can set this as a parameter in the constructor.
Without a specified charset, you are probably sending the data in UTF-8/UTF-16 (most common) which the server is interpreting in a different way.
EDIT: It looks like ISO-8859-2 doesn't support ñ. You may have to change something server-side. http://en.wikipedia.org/wiki/ISO/IEC_8859-2

You can try Html class. eg :-
jresponse = Html.fromHtml(jresponse);

Running a JavaScript command from MATLAB to fetch a PDF file

I'm currently writing some MATLAB code to interact with my company's internal reports database. So far I can access the HTML abstract page using code which looks like this:
import com.mathworks.mde.desk.*;
wb=com.mathworks.mde.webbrowser.WebBrowser.createBrowser;
wb.setCurrentLocation(ReportURL(8:end));
pause(1);
s={};
while isempty(s)
s=char(wb.getHtmlText);
pause(.1);
end
desk=MLDesktop.getInstance;
desk.removeClient(wb);
I can extract out various bits of information from the HTML text which ends up in the variable s, however the PDF of the report is accessed via what I believe is a JavaScript command (onClick="gotoFulltext('','[Report Number]')").
Any ideas as to how I execute this JavaScript command and get the contents of the PDF file into a MATLAB variable?
(MATLAB sits on top of Java, so I believe a Java solution would work...)

I think you should take a look at the JavaScript that is being called and see what the final request to the webserver looks like.
You can do this quite easily in Firefox using the FireBug plugin.
https://addons.mozilla.org/en-US/firefox/addon/1843
Once you have found the real server request then you can just request this URL or post to this URL instead of trying to run the JavaScript.

Once you have gotten the correct URL (a la the answer from pjp), your next problem is to "get the contents of the PDF file into a MATLAB variable". Whether or not this is possible may depend on what you mean by "contents"...
If you want to get the raw data in the PDF file, I don't think there is a way currently to do this in MATLAB. The URLREAD function was the first thing I thought of to read content from a URL into a string, but it has this note in the documentation:
s = urlread('url') reads the content
at a URL into the string s. If the
server returns binary data, s will
be unreadable.
Indeed, if you try to read a PDF as in the following example, s contains some text intermingled with mostly garbage:
s = urlread('http://samplepdf.com/sample.pdf');
If you want to get the text from the PDF file, you have some options. First, you can use URLWRITE to save the contents of the URL to a file:
urlwrite('http://samplepdf.com/sample.pdf','temp.pdf');
Then you should be able to use one of two submissions on The MathWorks File Exchange to extract the text from the PDF:
Extract text from a PDF document by Dimitri Shvorob
PDF Reader by Tom Gaudette
If you simply want to view the PDF, you can just open it in Adobe Acrobat with the OPEN function:
open('temp.pdf');

wb=com.mathworks.mde.webbrowser.WebBrowser.createBrowser;
wb.executeScript('javascript:alert(''Some code from a link'')');
desk=com.mathworks.mde.desk.MLDesktop.getInstance;
desk.removeClient(wb);