I wrote sql but it takes more time when execute it in jsp. And I want to make faster it. Will grid view make the page faster?
I'm junior in Java. I researched in google but didn't find clear sample about gridview. Can u help me?
I understand you have a web based application backed by the DB.
Note that gridview is not something offered by Java, instead you can create tables by using your web frameworks and render data there.
You say, it takes a lot of time to execute an SQL when running withing JSP. Where the time goes?
Running the SQL itself? Maybe creating a JSP or transmitting it to the client browser in an Html form, or even maybe the rendering of your table in browser?
You should detect the bottleneck in order to understand what you're going to fix
Consider to use profiler and see (at least on server vm) where the time goes.
I think JVisualVM will suit your needs here.
Hope this helps
I would have done this task using following steps
Create one servlet.
Connect to the database and fetch the data which we have to display.
Create a list and keep the data in list it.
Set the list in request and forward the control to JSP.
On JSP, use DisplayTag to show the data in grid form.
Hope this helps you.
Related
Good evening, I'm working on a project with a team, we have to make a browser without using JEditorPane or any other class that reads HTML.
How can we do that? Do we need to make a new class that does what JEditorPane does? Can I find somewhere JEditorPane's code? Thanks!
Well, this is an answer:
If you need to display web content without using any pre-existing engine (such JEditorPanel or a ChromeBind), you need to read the HTML as a XML file and construct your native View based on it (without CSS and JS this is a fairly easy task) by constructing the screen based on a one-to-one equivalent of a HTML tag to a Java JComponent.
Modern Web Browsers are pretty complicated, so there are a lot of different pieces that come together to display a web page. In order to build a browser, you need to first understand what a browser is. For that, I recommend reading this tutorial.
Once you have an understanding of how a browser actually works you need to determine which pieces you can reuse and which pieces you have to write from scratch. Do you have to write the entire rendering engine? Good luck! Can you use an existing engine like Gecko or Webkit? Or maybe you can get a little closer to done and use the java port of Webkit?
Once you have a better understanding of the question come back and ask more direct questions when you get stuck at a specific piece. As it is, your first step is to gain an understanding of the problem you are trying to solve.
I got a Freelancer work and now I am with some problems with the application. I was going to translate it to portuguese using jQuery and the unique ids of the elements. However I have some doubts about it.
I had no idea about the ExtJs and I read about it, then some questions came up:
Is the translation saved on a database?
Each field of the menu is saved on a database?
I realized that due the dinamic content loading the ids can be different everytime that day are loaded, is that true?
I know that the best way to translate it is not the one I've proposed. I thought about it before I see the code because I was thinking that it was a normal website. I already added the option of the Portuguese language on the login screen. However it sends the "pt" parameter and doesn't loads anything. It goes back to the default "en". The language parameter is send to a file Home.java where the doGet function is called. I couldn't find any file with the translation of it. Anyone can help me? I don't know how to do it (Load the menu in Portuguese). Thank you.
the website is:
http://brazil.chatlibs.com:81/bulkmessaging/
I don't think there's an easy way out for this. I did some translations for an ExtJS app and all I had was a JS class file with all the strings for both languages.
Then at application startup I'd call something like customStringsClass.setLocale('en'). This method would set customStringsClass.Labels, for example, to an object containing all the strings for the english language.
Then in controllers and views, I'd use customStringsClass.Labels.FirstNameField_Label
I want to write a word search,which connects to a specific website(huge one),takes the word from user,searches the site and returns the strings which contain the word;this should be written in java and as an applet.I have read some tutorials and questions on this,and understood what have to be done is:
1.connect to a website and get the content of a website and save it to a string.(this should be done with a webcrawler which will be made from my own code for connecting to website and save the content to a string + jsoup library to parse the html code).
2.save the datas to a database(in my case nosql database).
3.index the datas in database.
4.query the database to show the results.
5.make a UI for showing the search results(I use swing.japplet).
now my qustions are:
1.have I understood correctly the steps which I have to go?(please explain me in details if a step is unnecessary or necessary)
2.Is it necessary to have a database?
notice:I want to implement it myself,without using ready things such as lucene,nutch,solr,...
edit:3 people told me applet is not suitable for such a thing,so what should be the replacement?
many many thanks for your help.
You should look at using Lucene, as it does most of what you want here.
You should not use applets.
For small data set, database should be sufficient. Databases like mysql comes with full text search functions.
For bigger data set, you might want to consider Lucene or Solr.
That is one way way to implement this. Another (simpler) way would be to use an existing text search / indexing engine like Lucene / Solr. Going to the effort of reimplementing the "text search / indexing" wheel using database technology strikes me as a waste of effort, unless you have a sound technical reason for doing so.
You do need to has some kind of database, because indexing a website on the fly would simply not work. Lucene will handle that.
I think your choice of Java applets to build the UI is a bad idea. There are other technologies that give results that are as good or better ... without the security risk of a Java browser plugin.
Finally, another way to make your website searchable is to get Google to do it for you. Make your website content indexable, and then use Google's search APIs.
I am looking to develop an app that will take login details from the user, go to a website, login, return values on the web page and then display them to the user on the phone.
Does java have this functionallity? Will I need to use javascript instead maybe? do these answers depend on the website that I am trying to access?
In my head I figure that I could just read in the paramaters as strings or chars, parse the webpage for the appropriate form and "paste" the appropriate value into the form "box". However, I have never attempted anything like this with coding so I am completely new to the idea and dont really know where to start. I tried googling around but any information that I found was either irrelevant or conflicting.
I'm not looking for the code to do it because I will not really learn anythig from that but a finger in the right direction would be great. I really do want to try get better at programming so that's why I've started to give myself these little side projects
Any help that can be offered would be great
Ian,
You can try using http-client (http://hc.apache.org/httpclient-3.x/) lib from apache. It lets to pro grammatically access a website (from a Java code). You will need to do the following things
Use the http-client lib to POST the data to the web site.
Receive the html response.
Use some html parser or xpath to retrieve the values from the response html.
You would need a script which accesses the webpage and enters the data, but in my opinion this is illegal. Because you are accessing a secured area and are able to look into sensitive data. Also accessing the page via a script is "botting" - most pages have safety precautions to prevent the execution of scripts, because most of them are harmful.
In my opinion there is no legal and easy solution to this.
I have a Java program that I'm trying to interact with over the web.
I need to gather form data from the user on a Drupal site that I don't have any control over, send it to the Java program, and send the output back to the user. The Java program needs to load a lot of libraries every time it's run, so it needs to be up waiting for data from the user.
It'd be best for me to just have an HTML form for the input. What's the simplest way to deal with HTML form data using Java?
Also, I'm trying to call the Java program from a shell script. I want the program running in the background though so the libraries are loaded in advance. So ideally, I could use the server I set up for both applications.
Thanks for any help.
It sounds like you really just want to write a servlet (or use a higher level web framework, but a servlet would work fine). That makes it very easy to get web form data - you just ask for values by name, basically.
You could then "script" the application using curl, wget or something similar to make requests to the servlet.
Apologies if this doesn't answer your question - I'm finding it slightly tricky to understand exactly what you're trying to do, particularly as there are multiple layers of web UI involved, as far as I can see.
The easiest way to make POST requests with java is to use the Apache HttpClient or the more recent HttpComponents libraries.