Reading and Sorting from a CSV file

I have an assignment to read a shopping list from a CSV file, sort the items and print or write the items to a text file. I have an idea though. I intend to use vectors to collect the items from the CSV file and then sort the list and write to a txt file. Someone tell me whether this is a right approach or suggest simpler approach. thank you.
Derry

Sounds reasonable.
Rather than Vector, though, I'd use ArrayList (a very near replacement for Vector) or possibly LinkedList or even Set or Map. (Vector is a legacy class, kept around for backward compatibility.)
http://java.sun.com/docs/books/tutorial/collections/
Make sure each element in the List corresponds to one row in the file. Those elements should be a class you define whose member variables correspond to the columns in the file. (So if the file has Last, First, Bday columns, your class would have lastName, firstName, and birthday fields.)
Make your class Comparable, or implement a Comparator, to make sorting straightforward.
http://java.sun.com/j2se/1.4.2/docs/api/java/lang/Comparable.html
http://java.sun.com/j2se/1.4.2/docs/api/java/util/Comparator.html

Similar Messages

Reading and Writing from a text file at the same time

I know who to use the Scanner and PrintWriter to read from and write to a .txt file. But these are limited. How can I read and write at the same time? Such as open a file and change every third character or change every second word to something else and then write it back. I found this [http://java.sun.com/docs/books/tutorial/essential/io/|http://java.sun.com/docs/books/tutorial/essential/io/] but its a little over my head. Is this the only way to do it?

wrote:
You are using buffered reads and writes I would assume, right? Also, how do you think most programs handle this sort of thing? I don't believe I'm using buffering.
My code looks something like this
//...necessary imports
//then
Scanner inFile = new Scanner (new file("filename1.txt"));
PrintWriter outFile = new PrintWriter ("filename2.txt");
//then stuff like
int x = inFile.hasNextInt();
outFile.println(x);
camickr wrote:If you are changing the data "in place", that is none of the data in the file is shifted, then you can use a RandomAccessFile.
Otherwise, you've been given the answer above.What is RandomAccessFile? Is it what I have a link to? Basically what I do is I write a bunch of numbers to a txt file and then change the numbers I don't need anymore to 0. So say I had 0 1 2 3 4 5 6 7 etc. I would like to to open the txt file and change every second one to 0 so then I'd have only odd numbers and 0s.
I looked at the documentation for RandomAccessFile and it seems like it might be what I need.
Thankyou both for your help so far. I took a java course in high school and they only taught me one way to get data from text files and that is what I just showed you. So maybe this questions are really stupid. lol
Edited by: qw3n on Jun 13, 2009 7:46 PM

Help on Reading and Reporting From A log File

Hi there
I need any assistance on developing a class that is able to read from a log file and then be filtered and put into a report. I need to be able to search on the log files per criteria.

Chainsaw:
http://logging.apache.org/log4j/docs/chainsaw.html

Import data from excel/csv file in web dynpro

Hi All,
I need to populate a WD table by first importing a excel/CSV file thru web dynpro screen and then reading thru the file.Am using FileUpload element from NW04s.
How can I read/import data from excel / csv file in web dynpro table context?
Any help is appreciated.
Thanks a lot
Aakash

Hi,
Here are the basic steps needed to read data from excel spreadsheet using the Java Excel API(jExcel API).
jExcel API can read a spreadsheet from a file stored on the local file system or from some input stream, ideally the following should be the steps while reading:
Create a workbook from a file on the local file system, as illustrated in the following code fragment:
          import java.io.File;
          import java.util.Date;
          import jxl.*;
         Workbook workbook = Workbook.getWorkbook(new File("test.xls"));
On getting access to the worksheet, once can use the following code piece to access individual sheets. These are zero indexed - the first sheet being 0, the second sheet being 1, and so on. (You can also use the API to retrieve a sheet by name).
          Sheet sheet = workbook.getSheet(0);
After getting the sheet, you can retrieve the cell's contents as a string by using the convenience method getContents(). In the example code below, A1 is a text cell, B2 is numerical value and C2 is a date. The contents of these cells may be accessed as follows
Cell a1 = sheet.getCell(0,0);
Cell b2 = sheet.getCell(1,1);
Cell c2 = sheet.getCell(2,1);
String a1 = a1.getContents();
String b2 = b2.getContents();
String c2 = c2.getContents();
// perform operations on strings
However in case we need to access the cell's contents as the exact data type ie. as a numerical value or as a date, then the retrieved Cell must be cast to the correct type and the appropriate methods called. The code piece given below illustrates how JExcelApi may be used to retrieve a genuine java double and java.util.Date object from an Excel spreadsheet. For completeness the label is also cast to it's correct type. The code snippet also illustrates how to verify that cell is of the expected type - this can be useful when performing validations on the spreadsheet for presence of correct datatypes in the spreadsheet.
String a1 = null;
Double b2 = 0;
Date c2 = null;
                    Cell a1 = sheet.getCell(0,0);
                    Cell b2 = sheet.getCell(1,1);
                    Cell c2 = sheet.getCell(2,1);
                    if (a1.getType() == CellType.LABEL)
                       LabelCell lc = (LabelCell) a1;
                       stringa1 = lc.getString();
                     if (b2.getType() == CellType.NUMBER)
                       NumberCell nc = (NumberCell) b2;
                       numberb2 = nc.getValue();
                      if (c2.getType() == CellType.DATE)
                        DateCell dc = (DateCell) c2;
                        datec2 = dc.getDate();
                       // operate on dates and doubles
It is recommended to, use the close() method (as in the code piece below)   when you are done with processing all the cells.This frees up any allocated memory used when reading spreadsheets and is particularly important when reading large spreadsheets.
          // Finished - close the workbook and free up memory
          workbook.close();
The API class files are availble in the 'jxl.jar', which is available for download.
Regards
Raghu

Is there a way to select a certain box of elements from a csv file and read that into LabVIEW?

Hello all, I was wondering if there was a way to select only a certain "box" of elements from a .csv file in LabVIEW? I have LabVIEW 2011 and my main goal is to take two arrays and graph them against each other. I can import the .csv file just fine and separate each row and each column to be its own, but say I have an 8X8 but want to graph the middle 4X5 or something like that. Is there any way to extract an array without starting at the beginning and without ending at the end? Thank you in advance.
Solved!
Go to Solution.

Hi Szklanam,
as a CSV file is just a TXT file with a different suffix you can read a certain number of lines of that file. So you can limit the number of rows in your resultung array. To limit the number of columns you still have to use ArraySubset, so maybe it's a lot easier to read the full CSV file and pick the interesting spots with ArraySubset...
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome

Read and sort a semicolon seperated csv file

Hi all,
I need to sort the given csv file columnwise (alphabatically)... which means the corresponding row/rows also have to be sorted. need help.
the csv file looks like:
Wear;9;;;
;;;Image;1
;;;Area;2
;;;ner;3
;;;Content;1
;;;BContainer;1
;;;View;1
VIEW;10;;;
;;;get;8
;;;ner;1
;;;View;1
ACTIVE;21;;;
;;;Image;1
;;;get;7
;;;Area;4
;;;ner;1
;;;de.vw.mqbkombi.widgets.TransitionContainer;3
;;;Aget2;2
;;;ner2;1
;;;Sget;1
;;;iView;1
The idea is to first sort Wear,VIEW, ACTIVE alphabatically (columnwise), making sure all the rows that they have are also moved.
after that, alphabatically sort all the in-between rows.
would appreciate the help from any expert on csv, excel table.

doremifasollatido wrote:
If you know that your columns never have embedded semicolons, you could call String.split to split each row at semicolons. Although you could leave the results in the arrays that String.split gives, you should probably create a Java class to represent each row. It will make your code easier to understand, and you could also more easily represent numeric values as numbers such as primitive int values (so that they sort correctly as numbers instead of as Strings). Then create a List of instances of that Java class, and sort the list using Collections.sort and a custom java.util.Comparator.Or indeed make it Comparable; but I'd agree this is definitely the way to go.
Also, assuming that all your "secondary" rows, such as:
;;;Image;1
;;;Area;2
refer to the preceding "primary" (Wear;9;;;), I'd suggest you fill in the unsupplied values for them. That will allow you to sort them all in one go. It might also be worth including a type in your "Row" class (maybe as an enum); alternatively you could have two different subclasses of a common Row class.
Winston

Need to take a value from the csv file and query in a OAF page.

Hello,
I have a requirement to take the list of employee numbers in a csv file and display its corresponding job on the page.
I have created a item 'MessageFileupload' where the user will upload the csv file containing the employee number and a Button 'Display Jobs' which will display the corresponding jobs on the page.
Any idea how to take the values from the csv file and query it?
Regards,
den123.

Hi ,
Check
http://oraclearea51.com/contribute/post-a-blog-article/csv-file-upload-for-oa-framework.html
http://www.roseindia.net/jsp/upload-insert-csv.shtml
Below code works from above blogs.
package xx.oracle.apps.pa.Lab.webui;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
// import java.io.*;
import oracle.apps.fnd.common.VersionInfo;
import oracle.apps.fnd.framework.OAApplicationModule;
import oracle.apps.fnd.framework.OAException;
import oracle.apps.fnd.framework.server.OAViewObjectImpl;
import oracle.apps.fnd.framework.webui.OAControllerImpl;
import oracle.apps.fnd.framework.webui.OAPageContext;
import oracle.apps.fnd.framework.webui.beans.OAWebBean;
import oracle.jbo.domain.BlobDomain;
import oracle.cabo.ui.data.DataObject;
import oracle.jbo.Row;
* Controller for ...
public class deptCsvUploadCO extends OAControllerImpl
public static final String RCS_ID="$Header$";
public static final boolean RCS_ID_RECORDED =
        VersionInfo.recordClassVersion(RCS_ID, "%packagename%");
   * Layout and page setup logic for a region.
   * @param pageContext the current OA page context
   * @param webBean the web bean corresponding to the region
public void processRequest(OAPageContext pageContext, OAWebBean webBean)
    super.processRequest(pageContext, webBean);
   * Procedure to handle form submissions for form elements in
   * a region.
   * @param pageContext the current OA page context
   * @param webBean the web bean corresponding to the region
public void processFormRequest(OAPageContext pageContext, OAWebBean webBean)
    super.processFormRequest(pageContext, webBean);
    // Code Addition Started for CSV upload
    OAApplicationModule am = (OAApplicationModule) pageContext.getApplicationModule(webBean);
    OAViewObjectImpl vo = (OAViewObjectImpl) am.findViewObject("deptCsvVO1");
      //if ("GoBtn".equals(pageContext.getParameter(EVENT_PARAM)))
       if (pageContext.getParameter("GoBtn") != null)
      System.out.println("Button Pressed");
          DataObject fileUploadData =(DataObject)pageContext.getNamedDataObject("FileUploadItem");
          String fileName = null;
          String contentType = null;
          Long fileSize = null;
          Integer fileType = new Integer(6);
          BlobDomain uploadedByteStream = null;
          BufferedReader in = null;
                  try
                  fileName = (String)fileUploadData.selectValue(null, "UPLOAD_FILE_NAME");
                  contentType =(String)fileUploadData.selectValue(null, "UPLOAD_FILE_MIME_TYPE");
                  uploadedByteStream = (BlobDomain)fileUploadData.selectValue(null, fileName);
                  in = new BufferedReader(new InputStreamReader(uploadedByteStream.getBinaryStream()));
                  fileSize = new Long(uploadedByteStream.getLength());
                  System.out.println("fileSize"+fileSize);
                  catch(NullPointerException ex)
                  throw new OAException("Please Select a File to Upload", OAException.ERROR);
                  try{
                  //Open the CSV file for reading
                  String lineReader="";
                  long t =0;
                  String[] linetext;
                  while (((lineReader = in.readLine()) !=null) )
                  //Split the deliminated data and
                  if (lineReader.trim().length()>0)
                  System.out.println("lineReader"+lineReader.length());
                  linetext = lineReader.split(",");
                  t++;
                  //Print the current line being
                  if (!vo.isPreparedForExecution())
                          vo.setMaxFetchSize(0);
                          vo.executeQuery();
                    System.out.println("Trimmed "+ linetext[1].replace("\"", ""));
                  Row row = vo.createRow();
                  row.setAttribute("Deptno", linetext[0].trim());
                  row.setAttribute("Dname",linetext[1].trim().replace("\"", ""));
                  row.setAttribute("Loc",linetext[2].trim().replace("\"", ""));
                  //row.setAttribute("Column4", linetext[3].trim());
                  vo.last();
                  vo.next();
                  vo.insertRow(row);
                  catch (IOException e)
                        throw new OAException(e.getMessage(),OAException.ERROR);
          //else if (pageContext.getParameter("Upload") != null)
          am.getTransaction().commit();
          throw new OAException("Uploaded SuccessFully",OAException.CONFIRMATION);
}Thanks,
Jit

I have a VI and an attched .txt data file. Now I want to read the data from the .txt file and display it as an array in the front panel. But the result is not right. Any help?

I have a VI and an attched .txt data file. Now I want to read the data from the .txt file and display it as an array in the front panel. But the result is not right. Any help?
Attachments:
try2.txt ‏2 KB
read_array.vi ‏21 KB

The problem is in the delimiters in your text file. By default, Read From Spreadsheet File.vi expects a tab delimited file. You can specify a delimiter (like a space), but Read From Spreadsheet File.vi has a problem with repeated delimiters: if you specify a single space as a delimiter and Read From Spreadsheet File.vi finds two spaces back-to-back, it stops reading that line. Your file (as I got it from your earlier post) is delimited by 4 spaces.
Here are some of your choices to fix your problem.
1. Change the source file to a tab delimited file. Your VI will then run as is.
2. Change the source file to be delimited by a single space (rather than 4), then wire a string constant containing one space to the delimiter input of Read From Spreadsheet File.vi.
3. Wire a string constant containing 4 spaces to the delimiter input of Read From Spreadsheet File.vi. Then your text file will run as is.
Depending on where your text file comes from (see more comments below), I'd vote for choice 1: a tab delimited text file. It's the most common text output of spreadsheet programs.
Comments for choices 1 and 2: Where does the text file come from? Is it automatically generated or manually generated? Will it be generated multiple times or just once? If it's manually generated or generated just once, you can use any text editor to change 4 spaces to a tab or to a single space. Note: if you want to change it to a tab delimited file, you can't enter a tab directly into a box in the search & replace dialog of many programs like notepad, but you can do a cut and paste. Before you start your search and replace (just in the text window of the editor), press tab. A tab character will be entered. Press Shift-LeftArrow (not Backspace) to highlight the tab character. Press Ctrl-X to cut the tab character. Start your search and replace (Ctrl-H in notepad in Windows 2000). Click into the Find What box. Enter four spaces. Click into the Replace With box. Press Ctrl-V to paste the tab character. And another thing: older versions of notepad don't have search and replace. Use any editor or word processor that does.

Problem on reading and writing from from a *.txt file

I get Problem on reading and writing from from a *.txt file. The following is the read() method...
The software said the DataInputStream is depreciated. Can anyone help me please?
public void read()
    File file = new File("C://Documents and Settings//Charles//My Documents//Brunel//EE2065//Assignment and Lab//Assignment 4 and Lab 4//data.txt");
    FileInputStream in = null;
    String str = "";
    try
      in = new BufferedReader(file);
      //in = new FileInputStream(file);
      for(;;)
        str = new BufferedReader(in).readLine();
        //str = new DataInputStream(in).readLine();
        if(str == null)
          break;
        System.out.print(str);
    in.close();
    catch(IOException e)
        System.err.println("execution error: " +e);
}

Thank you for your reply. I have made some change. However, there is an incompetable type found error.
in = new BufferedReader(new InputStreamReader(in));The following are all of the code.
public void read()
    File file = new File("C://Documents and Settings//Charles//My Documents//Brunel//EE2065//Assignment and Lab//Assignment 4 and Lab 4//data.txt");
    FileInputStream in = null;
    //BufferedReader in = null;
    String str = "";
    try
      in = new BufferedReader(new InputStreamReader(in));
      //in = new FileInputStream(file);
      for(;;)
        BufferedReader Bstr = new BufferedReader(new InputStreamReader(in));
        //str = new BufferedReader(in).readLine();
        //str = new DataInputStream(in).readLine();
        if(str == null)
          break;
        System.out.print(str);
    in.close();
    catch(IOException e)
        System.err.println("execution error: " +e);

Reading and writing to a text file from an Applet

I'm a novice java programming with very little formal programming training. I've pieced together enough knowledge to do what I've wanted to do so far...
However, I've been unable to figure out how to read and write to a text file from an Applet (I can do it from a normal java program just fine). Here is a simple example of what I'd like to do (you can also look at it on my website: www.stat.colostate.edu/~leach/test02/test02.html). I know that there is some problem with permission/security but I'm not smart enough to understand what the error messages are telling or understand the few books I have. If anyone can tell me how to get this applet to work, or direct me to some referrences that would help me out I'd really appreciate it.
Thanks,
Andy
import java.applet.Applet;
import java.net.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.io.*;
public class test02 extends Applet {
public Button B_go;
public GridBagConstraints c;
public void init() {
this.setLayout(new GridBagLayout());
c = new GridBagConstraints();
c.fill = GridBagConstraints.BOTH;
B_go = new Button("GO");
c.gridx=1; c.gridy=0; c.gridwidth=1; c.gridheight=1;
c.weightx = c.weighty = 0.0;
B_go.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
print_stuff();
setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
this.add(B_go,c);
public static void print_stuff() {
try{
File f = new File("test02.txt");
PrintWriter out = new PrintWriter(new FileWriter(f));
out.print("This is test02.txt");
out.close();
}catch(IOException e){**/}
}

I have almost the exact same problem, and I am in the same situation as you are with respects to the language.
I am simply trying to create a file and output some garbage to it but my applet always spits back a security violation. I've tried eliminating the restrictions on the applet runner I use but I still get the error.
My method:
debug = new Label() ;
debug.setLocation( 20, 20 ) ;
debug.setSize( 500, 15 ) ;
add( debug ) ;
// output
try
     OutputStream file = new FileOutputStream( new File( "" + getCodeBase() + "output.txt" ) ) ;
     byte[] buffer = { 1, 2, 3, 4, 5 } ;
     file.write( buffer ) ;
     file.close() ;
} catch( Exception e )
     debug.setText( e.toString() ) ;
     Can anyone tell why this isnt working?

Is there a way to find and replace prices in an Indesign document from a CSV file?

Is there a way to find and replace prices in an Indesign document from a CSV file. Currenty I have a catalog with codes and prices in tables. I need to find a way to look up the code (and new price) in the CSV file and overwrite the price in the current table with the new price. Does anyone know of a script to run this quickly?

Hi,
Try this
1) with all the images showing, got to Find -> By caption or Note
2) enter the caption you are looking for Image Description and click on OK
It should display all the ones with that caption
3) select a few images as a test
4) go to Edit -> Add caption to selected items
5) if you want to blank out the captions just check the box to replace the caption and click on ok
6) You will need to confirm the blank captions
You could use a similar procedure to change the caption to something else.
Good luck
Brian

Reading each value from spreadsheet file with delay (multiple rows and columns)

Hi,
a) I want to read EACH VALUE from a spreadsheet file having multiple rows and columns WITH DELAY. I am attaching my VI and sample datalog file for reference (tempsensor.txt).I need to do so because as soon as I read put ON the Sensor button on front panel, LV reads all the values at one go. I need the values for each temperature to be displayed after a delay.
b) Secondly, I would like to read another file containing the state of four antennas (deployed:1; undeployed:0). I am logging state of each antenna in each column of the file(magnet.txt) I need to have four LEDS on front panel to display state of the antennas. I dont know what I have done for antennas in my VI is right or wrong. I guess thats rhe wrong way to approach the problem. Please help!!!(column1: Antenna1 state ; Column2:Antenna2 state.. and so..on..)
Any help would be greatly appreciated!!
Thanks in advance,
Ratnesh
FYI: The first column in my datalog file represents timestamp(number of seconds elapsed), second column: reading for temperature sensor 1, third column: reading for temperature senosr 2, and so on. I am using approx. 11 temperature sensors.
Also, I have generated the log files for the reference purpose only. They do not represent the actual values. They are far away from actual values.
Attachments:
01032005.zip ‏30 KB

Look at this modified version of your VI. After looking at it, I determined that a shift reggister was not required in this case.
Lynn
Attachments:
MultiSensors.2.vi ‏85 KB

How do I remove e-mail addresses from a csv file referencing a numbers doc

Greetings! I hope someone out there can help me. I'm not exactly a genius when it comes to numbers...
My Issue:
I'm attempting to sending out a large e-mail blast via software called hoolie, it seems to be working amazingly well except for the fact that I've reached our Gmail accounts daily limit which I had zero idea existed.
So about 1100 emails were sent and I still have to send about 1500 emails left to be sent. The software has no ability to resend to the failed e-mail addresses, so I'm left to my own devices...
My Goal:
I want to be able to subtract out the 1100 e-mail address from the csv file I have with all the addresses. Once I subtract out the e-mail addresses I can then resend the blast and throttle it so it takes a day or so and won't freak out google gmail...
How can I accomplish this? I have the orginal CSV file with all the names and e-mail addresses and I have a new numbers doc in which I pasted the e-mails that were succesfully sent...
Thoughts? Suggetsions?
thanks in advance!

Are you suggesting that it sent it to a random sample of the email addresses, that it did not start at the beginning and go row by row until it failed? If that is the case, you can import the CSV file into Numbers, paste your list of sent addresses in another column or another table of that document, then use COUNTIF to look for duplicates.
The best I can do is an example.Your table will no doubt be different so you'll have to rejigger the formula.
Importing your CSV file will create column B
Insert two new columns, C and D
Use Copy/Paste to copy/paste your list of sent addresses from your other document into column D
The formula in column C is =IF(COUNTIF(D,B)>0,"Was Sent","")
Once it has done its thing, sort by column C to get all the "Was Sent" rows together. Delete them. Delete column C, Delete column D. Share as a CSV.

How can i import contacts from a csv file to "iCloud Contacts"?

How can I import contacts from a csv file to "iCloud Contacts"?

The only way I know of to import cells from a csv file is by creating a new file. But then you can select the desired cells and copy them to the other file. I just did it to be sure it works.
1. Create the new spreadsheet file via the upload command.
2. Select the cells (table) that you want to move to the other file and press command+C (copy).
3. Close the new file and open the existing file.
4. Select the top/right cell of the area to receive the copied "table" and press commant+V (paste).
I hope this is what you're trying to do!

How to import categories to my addressbook from a csv file?

Hello, I have a few contact list (csv) i want to add in my thunderbird adressbook. tought, I can' t find a way to add the categories of my contacts when i import my list of contacts from a csv files to my thunderbird adressebook. As you can see in the image, in the Edit contact window there is a section named categories, and ussually you click that section and you decide whatever the contact is a friend, a parent etc. Well I want to import that information from a csv file already made and not setup up the categories from each contact one by one. Ok thank you very much!

You need a vCard (.vcf) format, not .csv. Were these exported from Outlook?

Reading and Sorting from a CSV file

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