I created an applet that requires a CSV file for information. The way the applet works, is that there is a text field in which you type in your zip code, then you press a button. That causes the program to parse through the CSV file which contains a latitude and longitude, then display the latitude and longitude on a JLabel in the applet.
When I created it, I debugged it and tested it, so I know it works on my desktop (when running in eclipse). The problem is when I put in on the web, it displays but can't do anything, meaning it is just an applet with a text field and a button, but when you press the button, nothing happens. I know that it is not my ActionListener, because it works on the desktop, but I must be doing something wrong with the HTML of it. The name of the CSV file is zips.csv. The name of the main class is main.class (or main.java) and the action listener is myActionListener.class (or myActionListener.java).
Here is the HTML that I am using for it right now:
<applet archive="sites/default/files/myApplet.jar" code="main.class" width="500" height="200">
</applet>
Revision:
Romething else that someone recommended to me was to create a php script that will parse the csv file, and than have that return a value to the java applet. My knowledge of PHP ls limited, so I was wonder if someone could tell me how I could go about doing this, or telling me where I can learn how to do this.
CsvReader products = new CsvReader("zips.csv");
My crystal ball tells me that CsvReader presumes the String to represent a File object. It might also have another constructor that accepts an URL.
A sand-boxed applet cannot access File objects, and a trusted applet can only access File objects on the computer of the end user. That is useless to this applet. If the API has a constructor that accepts an URL, that is the one to use here. Something like:
URL url = this.getClass().getResource("zips.csv");
//CsvReader products = new CsvReader(url);
InputStream is = url.openStream();
CsvReader products = new CsvReader(is);
A constructor that accepts an InputStream is even more versatile, and only a line longer.
If the CsvReader accepts neither of URL or InputStream, I suggest you find another API. One that was not written by amateurs.
Related
I'm a Uni student trying to multiply two matrices stored in txt files via java and Eclipse. We were given a pre-compiled class file, but not the source code for the class file, essentially making it a blackbox class. We're supposed to use vim and the Linux terminal to program and execute our java code, but I find that Ecplise is far more time-efficient. However, when using the Linux terminal and vim my program works as intended, whereas when using Eclipse it does not.
Here's my source code with only the LOCs using the blackbox class
String fileOne = ArrayReader.getFileName("Enter the file name of matrix one");
int[][] matrixOne = ArrayReader.readArray(fileOne);
String fileTwo = ArrayReader.getFileName("Enter the file name of matrix two");
int[][] matrixTwo = ArrayReader.readArray(fileTwo);
The getFileName function outputs the argument, expecting the user to enter the file name (including the extension) of the file with the elements of the matrix in it. If it doesn't find the file, it returns an error message stating so, then asking for the file name again. The readArray function simply gets the elements and assigns them to the elements of the integer matrix.
I've tried putting the txt files in both my src and bin folders in my project directory, and inputting the file names with and without the file extension multiple times, but to no avail.
Any ideas?
I should put this in a comment but i don't have enough reputations
*Can you provide more details about the error so we can help and try to decompile the class to view it's source code you may find your answer also you can hardcode the file name (write it directly in the code) to test if everything works correctly *
The ArrayReader class expects the computer to be using Linux, not Windows.
In my new app I wanted to make an IO object that will help me access text files written in a raw folder located in the res folder.
The object is a java class that is written in the same location as all of the rest java files.
The goal of this object is that I can access files from all of the activities instead of writing them again and again.
But when I tried to do that I stumbled upon a few errors that I can't find a way to fix them.
While writing the code:
FileOutputStream fos = new FileOutputStream(R.raw.fName);
(fName is a Sting that the action receives)
Android studio marked the "raw" red and said it didn't recognize it.
From what I understand the R file doesn't recognize the raw folder.
The second problem is , when I write the code:
InputStream is = Context.this.getResources().openRawResource(R.raw.fName);
It still gives me an error at the raw and an error at "Context.this" , and asks me to split the deceleration or to surround it with a try block , which doesn't help. And at the headline there is a throws IOException so any errors with IO should be cleared.
And if there is an easier way to access actions in java files , a link or an explanation will help a lot.
P.S. a raw folder is a premade folder with premade text files , also an easier way to read and write in premade files will help.
I have an URL http ://......../somefolder/ I want to get the names of all the files inside this folder. I have tried this below code but it's showing error.
URL url = new URL("http://.............../pages/");
File f=new File(url.getFile());
String list[]=f.list();
for(String x:list)
{
System.out.println(x);
}
Error :-Exception in thread "main" java.lang.NullPointerException
at Directory.main(Directory.java:25)
It's not possible to do it like this.
HTTP has no concept of a "folder". The thing you see when you open that URL is just another web page, which happens to have a bunch of links to other pages. It's not special in any way as far as HTTP is concerned (and therefore HTTP clients, like the one built into Java).
That's not to say it's completely impossible. You might be able to get the file list another way.
Edit: The reason your code doesn't work is that it does something completely nonsensical. url.getFile() will return something like "/......./pages/", and then you pass that into the File constructor - which gives you a File representing the path /....../pages/ (or C:\......\pages\ on Windows). f.list() sees that that path doesn't exist on your computer, and returns null. There is no way to get a File that points to a URL, just like there's no way to get an int with the value 5.11.
Until now I did saving image into the webapp directory and its path into database.
But now am trying to save the image outside of the webapp so that if I deploy my new war files then my old files folder will not be deleted.
From my below code my image file is correctly saving into the specified folder outside of the webapp but i don't know how to retrieve that image into my jsp page.
I tried like this
<img src="www.myproject.com/struts2project/files/smile.jpg/>"
but this is wrong. I am not getting my image to be display into my jsp page.
Below code is working fine for uploading image into absolute path but my problem is how to retrieve that image?
`fileSystemPath= "/files";
try{
File destFile = new File(fileSystemPath, thempicFileName);
FileUtils.copyFile(thempic, destFile);
String path=fileSystemPath+"/"+thempicFileName;
theme=dao.getThemeById(themId);
theme.setThemeScreenshot(path);
theme.setThemeName(theme.getThemeName());
theme.setThemeCaption(theme.getThemeCaption());
dao.saveOrUpdateTheme(theme);
}catch(IOException e){
e.printStackTrace();
return INPUT;
}`
Kindly help me...
I hope I'm being clear on what I need, let me know if I am not and I'll try to explain in another way.
As you say . . . this question describes what you need to do. I guess what you need to know is how to best achieve this with struts 2. Here's what's going on.
In your tag:
That url is being routed to your struts 2 application. Correct? The context is "struts2project".
One of the solutions offered by the referenced question is to use Tomcat's ability to serve static requests and configure tomcat to know about this other document root that holds your images. I think this is a great solution.
If you want to keep it inside of struts2, I think you're best option is to use a dedicated "image streaming from that other place" action that get's an InputStream to the image, then uses the Struts2 Stream Result result type. That result type lets you specify an adhoc InputStream. It also helps you set the appropriate headers. Note, the header values on that documentation page are for downloading the file, so you don't want those values. They would force the browser to open a save as dialog for the image, I think.
You are already using absolute paths, just use a location outside of your web application:
String destinationDir = "/path/to/my/directory/";
File file = new File(destinationDir + item.getName());
I have a scheduled task running in JBoss 5.1 on a daily basis for sending birthday wishes.
The mail content is HTML and I embed images in the mail.
Now I would like to get the path of that image for embedding, how would it be possible to get path of image in a non-servelt environment.
Ofcourse I could have placed the images at a static location and accessed them, for which I don't want to hardcode the path.
The image is at "WebContent/images/birthday.jpg" location.
How are you generating the email content? Are these also static html files?
If you are going to use simple static html files, you will have to hard code the image paths. There is no other way around it.
You could write a simple Java application, which runs as a standalone application (without any servers,servlets etc), which will create the email content.
The java code can send out the emails for you too if you want.
These are some of the things you can do, if you use java
Use property files to specify the location of images. These are files which hold simple key/value pairs.
You can easily create multiple email content to different users, with the same template.
You will be able to easily redesign the html content for multiple users.
An example of using property files.
Create a file ex: "email_template.properties"
Enter the following into the file and save it.
image_server=http://www.mywebsite.com
image_folder=/WebContent/images/
Create a jave program to create your html email, and use the property file to generate the image locations.
Properties properties = new Properties();
try
{
properties.load(new FileInputStream("C://email_template.properties")); //specify path here
String sServerLocation = properties.getProperty("image_server");
String sImageFolder = properties.getProperty("image_folder");
StringBuilder strEmail = new StringBuilder();
strEmail.append("<html><body> <img src=\"" + sServerLocation + sImageFolder +"birthday.jsp\""> </body> </html>" );
// Write code to generate complete email dynamically
// write code to send out the email or to save as html file to you machine, where you can send it manually.
} catch (IOException e)
{
//
}
You get the idea. using plain html you will have to hard code.
However if you use a simple java file you can get more flexibility.
If you need code to send out email from java, check this link out.
How can I send an email by Java application using GMail, Yahoo, or Hotmail?