Creating New Properties File Appending If It Exists
Feb 4, 2015
I'm currently working on a java project simply to learn java. So far, it creates a window and makes a properties file, or appends data to it if it already exists. The problem is that I'm not quite sure how to check if the file already exists to append data to it. I'm currently using a boolean (configCreated) that appends data when true, and creates a file when false. The problem is that this boolean is always false since it's at the beginning.
class CreateFile implements ActionListener{ // MailOrderCreateFile.java @Override public void actionPerformed(ActionEvent ae){ String getDestination = txtDestination.getText(); file = new File(getDestination); // needed for Creating and Displaying the file currentTime = txtCurrentTime.getText(); try { FileWriter fw = new FileWriter(file);
[Code]...
What I wanted to do is that every time I press the button that will activate this part of the code, it will write to a .txt file defined in my txtDestination var (a JTextField). After the first time the file was created, it must append a new line every succeeding presses. However, everytime I do this, it just simply overwrites the contents of the .txt file. The example output would have been like this:
First time.
O R D E R D E T A I L S: Time ordered: 01/21/2015 Wed 10:21:54 PM Item number: 10 Item price: $4.59 Quantity ordered: 12,321 Total: $56,553.39
I am at a loss when it comes to appending Strings to a text file in Java. I was tasked (yes, homework) to complete a program that does the following simple things:
Print out the contents of a text file to the user (got that!)
Ask the user if the want to add any customers to this text file (got it!)
Add those customer's name's, addresses, postal codes and cities. (got that too)
Verify the postal code is in the proper format (yep!)
Add the new information to the text file, and display it to the user (Nope...)
The program is, essentially, supposed to keep track of the user's customers, and store this information to a text file. However, when I run the following code, I get a number of errors:
I do most of my file I/O with {Scanner} for input and {PrintWriter} for output. I've got lots of places in my code that looks like:
Scanner source = new Scanner( new File( sourceName)); PrintWriter dstntn = new PrintWriter( new BufferedWriter( new FileWriter( dstntnName)));
But when I call the constructor for {PrintWriter} up above, it overwrites whatever the original contents of the file designated by {dstntnName} were, doesn't it? Is there a way to call the constructor so that any future writes to it simply append to the original contents, instead of overwriting them?
Logic her eis when user selects option1, it asks for user to enter name and as soon as user enters name, it should compar name to existing names in txt file. I have user while loop and for loop but for some reason, it doesnt compare properly as there seems to be some mistake in looping and it just read first line or you can say single line rather than comparing it with all lines in txt file. i have attached votes.txt file with this. Also, if user doesnt exists infile, it will ask user to enter vote as yes or no and add it to file and then count total number of Yes and No votes from file and compare them.
my votes.txt file looks as below with two columns namely (name and vote).
Hiren No samir yes bob no rikul no master yes patrick no summer yes bhanja no
I am kind of new to programming in java and I am trying to run a first time setup type of thing for my program so I am saving the settings to a file. If the file doesn't exist I want it to run the first time setup but if the file does exist I want it to skip that process. My problem is that .exists() says reads true whether the file is there or is not there.
public static void main(String[] args)throws IOException{ new Window(); //Runs the Window() PrintWriter writer = new PrintWriter(path); boolean bool = new File("path.txt").exists(); System.out.println(bool); if(!new File("path.txt").exists()){
I'm not too familiar with serialization.It actually I found at this site (Java - Serialization) says that it will write and read properties of an object. I'm not quite sure how this would work as I would have thought that writing it to a text file would just do a toString() when you wrote it, but the page seems to think otherwise, and also names it .ser or something instead of .txt.
I thought, maybe this would work with my idea for a notepad that could store a Font, font color, and other settings, for the file. It would be beyond normal notepads. However, could you do this for a file as it would store text plus other things.
The upshot of this is that the same file, I was hoping to be able to be read by regular text programs like Notepad. However, could Notepad read such a modified file? Also, if notepad wrote to it, would it destroy my font properties and stuff that I'd add to it?
Also, what does this mean:
Warning: Serialized objects of this class will not be compatible with future Swing releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Swing. As of 1.4, support for long term storage of all JavaBeans™ has been added to the java.beans package. Please see XMLEncoder.
Originally, I was going to use FileAttribute or something like that but it looked hard to do and likely not what I wanted. However, this looks more like what I want, but I'd like to know. This could be a huge breakthrough for a lot of things I was hoping to do but never could think of an efficient way to do.
Update:This serializable thing works great for my text editor but it won't work too hot if another program like Notepad reads it as it will appear like gibberish, including the text.
I had thought of having it make two files, one regular, and one that was serialized, to deal with this, but this doesn't work if I try opening a file that another text editor created that might not have this other serialized version of the file.
Also, I haven't yet tried extending File itself yet. However, I still don't see how it would work the way I'd hoped.
In a way, I want it to be like a RTF with some things used to set te font of the text area when loaded but be able to deal with opening a file made by another text editor and also have another text editor be able to read it even if my text editor created it.
File destHtmlFolder = new File("C:/bea/user_projects/domains/OICDomain/DOC_SERVER/REPORT_HTML_DUMP"); File srcExcelFolder = new File("C:/bea/user_projects/domains/OICDomain/applications/IIMS/IIMS/target/source/REPORT_EXCEL_DUMP");
I have a problem. Depending on one of the request variables, i need to load different properties files. All these property files have same keys, but with different messages. I need to take the user to different sites(though internally, the backend logic remains same...Look and feel of the front end along with messages to be shown change to make the users feel they are being directed to a different site).
I am thinking of loading the properties file from the JSP when the user logs in first time from login page so that these properties are available until the session expires & not read the properties file in Controller.
In my java app there is a code which reads the properties file from src/main/resources folder.
Java Code:
@Component("mailerProperties") public class MailerProperties { private static Properties properties; public MailerProperties() { properties = new Properties();
[Code] ....
Now I need to create a jar file and also remove the properties file from src/main/resources folder and place it outside the jar file(in the same location as jar file) so that data inside it can be changed easily in future.
Question: Currently it uses ClassPathResource("mailer.properties") to read the prop file. What change I need to make to read it from outside the jar file...
The code for my button is below - I know it is wrong and that I need to change line 8 at least,so I am technically asking the property object if there is a key_name there but I dont quite get how to do that
//code for button
JButton btnSearch = new JButton("Search"); btnSearch.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { //find selected command String key_name = textFieldSearch.getText();
[Code] ....
I basically just want the user typed in word to be checked against a keyword in a properties file and if it exists, pull the key and the value back into a panel
and, have a response class file, which is setting a response from database to display it on `JSP` file. The value that I am getting from database is in the form of `code` or `integer`. I needed to have that value from the database and before setting the response I need to use `getProperty(code)` and save the String representation of that code into a new list and then pass that list to `setResponse`. For e.g: This is the value I am getting from database:
col1 | col2 | col3 | 1 helo done
I needed to show on my JSP page as:
col1 | col2 | col3 | USA helo done
I was following this tutorial [URL].... but not able to exactly understand how to achieve the same.
This is my `DAOImpl` where I needed to `iterate` and save the `mapped key-value` in a new list and then pass to `JSP` page
public class CountDAOImpl implements IDataDAO { private Connection conn = null; private Statement statement = null; private ResultSet rs = null; private List<String> country_code = new LinkedList<String>();
The code for my button is below - I know it is wrong and that I need to change line 8 at least,so I am technically asking the property object if there is a key_name there but I dont quite get how to do that
//code for button
JButton btnSearch = new JButton("Search"); btnSearch.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { //find selected command String key_name = textFieldSearch.getText();
[Code] ....
I basically just want the user typed in word to be checked against a keyword in a proeprties file and if it exists, pull the key and the value back into a panel ....
When we have a property in the jnlp file that has accented characters (i.e. Mañana), the System.getProperty() call is returning null. This is working fine with Java 7 Update 40, and accented characters in the <information> section of the jnlp file are working fine under Java 7 Update 45, but not in the <resources> section.
I need to write the exact directory path like C:LisaestUpdate to a properties file.
I am trying it by
FileInputStream in = new FileInputStream(test.properties); Properties props = new Properties(); props.load(in); in.close(); FileOutputStream out = new FileOutputStream(newprop.properties); props.setProperty("myDirectory","C:Lisa estUpdate" ); props.store(out, null); out.close();
but the properties file is updated as C:Lisa estUpdate
Extra comes before :.
How can I remove that.
Even I tried it with an command but got same output.
I have a properties file with key values in it, now when I use my search box to search for a key in the properties file to check whether or not it is there - I can't get it to check and return the key value if it is theere. I've tried a few methods but keep getting a null pointer exception when it hits line 15 in the code all the time so I'm stumped at the minute.
There's loads of problems with this. What I'm trying to do.
1) get a program to add the contents of an array together, preferably with a for loop and not the heavy handed version I've tried to use here.
2) get the for loop's output just once, since it won't compile or recognise the variable outside of the loop. How do I make the loop's 'counter' variable available everywhere?
public class retint { public static void main(String[] args){ int[] onetoTen = {1,2,3,4,5,6,7,8,9,10}; for (int i=0; i<10; i++) { int counter = (onetoTen[0] + onetoTen[1] + onetoTen[2] + onetoTen[3] + onetoTen[4] + onetoTen[5] + onetoTen[6] + onetoTen[7] + onetoTen[8] + onetoTen[9]); System.out.println(counter); } }
Terrible code, I know. There has to be a more efficient way.
I have tried this code to insert into datbase if not exists but i get an Exception in thread "main" com.mysql.jdbc. exceptions.jdbc4. MySQL SyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'WHERE NOT EXISTS (SELECT teamName FROM Teams WHERE teamName = teamName) LIMIT 1' at line 1
stmt.executeUpdate("INSERT INTO Teams(teamId,teamName,league) VALUES ("+i+",'"+loser+"','"+league2+"')WHERE NOT EXISTS (SELECT teamId,teamName,league FROM Teams WHERE teamName = teamName) LIMIT 1;");
I need to check the existence of email accounts before sending them mails to avoid going to a blacklist for sending to non real accounts.
I was thinking on (SSL)Sockets and smtp commands but I cant get it to work properly I am shooting in the dark here...
I have a JAVA application that sends mail to the people that buy certain things but the information quality is bad, so I must check if the mail exists before sending the mail....
I am working on a project that requires me to build a database with random access file, representing products, the base product contains a name (about 30 characters), a price (double), and a quantity (integer). I have worked on this project for probably 15+ hours and have tried so many things and feel like I've barley made any progress...
The part i am really struggling with is taking the data from the text file and creating an object array with it using the product class. Once ive accomplished that, i have to use that data to create a random access file with the data.
Here is the base Product class that must be used to create the objects for the array.
public class Product { public String pName; public String stringName; public double price; public int quanity;
[Code] .....
And then here is the data from the text file that i must extract to use to create product objects.
These continue for about 40-50 entries, they are not separated by a blank line though i had to add those so it would display correctly, each entry is on its own line with name separated with spaces, then price after a comma, then quantity after the second comma.....
I am working on a project that requires me to build a database with random access file, representing products, the base product contains a name (about 30 characters), a price (double), and a quantity (integer). I have worked on this project for probably 15+ hours and have tried so many things and feel like I've barley made any progress...
The part i am really struggling with is taking the data from the text file and creating an object array with it using the product class. Once ive accomplished that, i have to use that data to create a random access file with the data.
Here is the base Product class that must be used to create the objects for the array.
public class Product { public String pName; public String stringName; public double price; public int quanity; //Constructor public Product( String pName, double price, int quanity )
[code]....
and then here is the data from the text file that i must extract to use to create product objects.
Dill Seed,938,34
Mustard Seed,100,64
Coriander Powder,924,18
Turmeric,836,80
Cinnamon (Ground Korintje),951,10
Cinnamon (Ground) Xtra Hi Oil (2x),614,31
Cinnamon (Ground) High Oil (1X),682,19
these continue for about 40-50 entries, they are not separated by a blank line though i had to add those so it would display correctly, each entry is on its own line with name separated with spaces, then price after a comma, then quanity after the second comma.....
I am new to java and I am creating a system that will ask the user to create a file that will store to a text file, Once the user created the file I have a class that will let the user input the subject name that has been created, However, I keep on getting this java.util.nosuchelementexception.Here's my code:
public void display_by_name() { String id, name,total; String key[]=new String[30]; String value[]=new String[30]; int i=0;
I need to write a program that will create an inventory file as a random access file. The problem that I am having is that among the things I need to add to the random access file is a "car name". Since random access files are byte based I don't know how I could possibly write and then read a string value.
Though have been playing around with my ebook but finding it difficult to get along with the topic PACKAGE&INTERFACES, I find it challenging to write a package file despite the book I currently studying and online tutorial.. so I want a more explanatory format to comprehend the piece cos without knowing it.
I'm having a problem with using the openCSV library when I create a JAR file. I'm currently using BlueJ to run my code. When I compile my program in there, I have no problems whatsoever and it runs great, yet when I create my program into a JAR file, my application doesn't work.
I would think that my problem is either stemming from faulty exception handling, although I don't understand why an input would work in the BlueJ environment, but not when using the JAR file. Or, perhaps the openCSV library isn't in a correct class path(I don't know if this is correct terminology).
