Hi guys,
I’m very new to maven, vaadin and java applications in general, so I hoped you could help me with this as I’m not sure what’s the best way to go about it.
Basically I have a maven project (java 7) which, using javascript, creates a popup window with a form inside, allows you to upload a file, display its content in a textarea and send it (the content of the file as a string) to the server via an ajax request. That was the easy part.
What I want to do now is to access that data sent through ajax (the string containing the data of the uploaded file) in Java because I need to run it through some validation.
I had a good look around, including the book of vaadin, and the net in general and considering that I have never done this before, it seems that one way could be to have a connector, but it looks a little too complicated and also it appears - from what I understand from the book of vaadin https://vaadin.com/docs/-/part/framework/gwt/gwt-overview.html - that I won’t be able to implement that in my project given the structure I have - which is different from what’s in there.
So, my question to you guys is, given the project I have (just a normal maven project) what would be the easiest way for me to access this data from Java?
Here is some code from the project, to put things into context:
import javax.servlet.annotation.WebServlet;
import com.vaadin.annotations.Theme;
import com.vaadin.annotations.VaadinServletConfiguration;
import com.vaadin.annotations.Widgetset;
import com.vaadin.server.VaadinRequest;
import com.vaadin.server.VaadinServlet;
import com.vaadin.ui.Button;
import com.vaadin.ui.Button.ClickEvent;
import com.vaadin.ui.JavaScript;
import com.vaadin.ui.Label;
import com.vaadin.ui.UI;
import com.vaadin.ui.VerticalLayout;
import com.vaadin.client.ui.*;
@Theme("mytheme")
@Widgetset("my.vaadin.apptest.MyAppWidgetset")
@com.vaadin.annotations.JavaScript({"https://ajax.googleapis.com/ajax/libs/jquery/1.12.2/jquery.min.js"
})
public class MyUI extends UI {
@Override
protected void init(VaadinRequest vaadinRequest) {
final VerticalLayout layout = new VerticalLayout();
layout.addStyleName("myLayout");//add class to main div
Label label = new Label("Hello Vaadin user. Use this application to upload files.");
...
//HERE IS THE JAVASCRIPT CREATING AND INSTANTIATING THE POPUP AND THE AJAX CALL
//CREATING POPUP
JavaScript.getCurrent().execute(""
+"var $HTMLpopup = $('<div class=\"popupContainer\">"
+"<span class=\"cancelBtn big\"></span>"
+"<div class=\"wrapper\">"
+"<form action=\"\" id=\"fileForm\">"
+"<div class=\"mask\">"
+"<input type=\"file\" title=\" \"name=\"uploadFile\" class=\"uploadFile\" accept=\".mol,.sdf\">/*filters files to upload*/"
+"<span class=\"pseudoBtn\">Browse</span>"
+"<input type=\"text\" name=\"displayFile\" class=\"displayFile\" placeholder=\"no file loaded\">"
+"<span class=\"cancelBtn small\"></span>"
+"</div>"
+"<textarea class=\"fileResult\"></textarea>"
+"<button type=\"submit\" class=\"submitBtn\">Upload</button>"
+"<div class=\"clear\"></div>"
+"</form>"
+"</div>"
+"</div>');"
//INSTANTIATING THE POPUP
+"$('.popupTriggerBtn').click(function(){"
+"/*console.log('button clicked!');*/"
+"var $body = $('body');"
+"$HTMLpopup.appendTo($body);"
+"});"
//HERE IS THE AJAX BIT
+"var $submitBtn = $HTMLpopup.find('.submitBtn');"
+"$submitBtn.click(function(e){"
+"e.preventDefault();/*prevent submission*/"
+"if(isFileUploadEmpty()){/*IF EMPTY*/"
+"/*alert('submit clicked');*/"
+"removeError();"
+"showError('empty');"
+ "}"
+"else{/*IF NOT EMPTY*/"
+"/*AJAX OPS*/"
+"if (window.XMLHttpRequest){/*XMLHttpRequest SUPPORT?*/"
+"console.log('XMLHttpRequest supported!');"
+"var postData = returnFileAsString();/*returns the file as a string*/;"
+"/*console.log('here is the file as a string ' + postData);*/"
+"$.ajax({"
+"type:'post',"
+"url:'http://localhost:8080/apptest/',"
+"data:postData,"
+"contentType: 'application/x-www-form-urlencoded',"
+"success: function(responseData, textStatus, jqXHR){"
+"/*alert('data saved');*/"
+"console.log('responseData is ' + responseData);"
+"console.log('text status is ' + textStatus);"
+"console.log('the data submitted is ' + postData );"
+"},"
+"error: function(jqXHR, textStatus, errorThrown){"
+"console.log(errorThrown);"
+"alert('an error has occurred!');"
+"}"
+"});"
+"}"
+"}"
+"});"
+"");
//ADDING COMPONENTS
layout.addComponents( label, button );
layout.setMargin(true);
layout.setSpacing(true);
setContent(layout);
}So, postData contains the string that I passed to the server and that I’d like to access in Java.
I came across this earlier on, which may or may not be another way to deal with it http://stackoverflow.com/questions/13861103/vaadin-with-ajax#13883449. What do you guys think?
Any help would be much appreciated, thanks