Writing To Excel File From Database Including Column Names
Dec 17, 2014
I need to print contents of database to excel file.Apache POI is the solution but I am not finding a way to print the DB column names/headers into the excel.
E.g.:
incase csv we have opencsv CSVWriter writer = new CSVWriter(new FileWriter(fileName));
System.out.println("writer");
writer.writeAll(rs, true);
will print the db contents with the column headers dynamically whatever the query may be.
Any solution where we can print data and column names without know the query previously as we are getting query at the run time and each time the query is different.
I'm having a bit of trouble with using the Scanner and the Printwriter. I start with a file like this (1 = amount of Houses in the file)
1 FOR SALE: Emmalaan 23 3051JC Rotterdam 7 rooms buyprice 300000 energylevel C
The user gets (let's say for simplicity) 3 options:
1. Add a House to the file, 2. Get all Houses which fullfil requirements (price, FOR SALE / SOLD etc.) and 3. Close the application.
This is how I start:
Scanner sc = new Scanner (System.in); while (!endLoop) { System.out.println("Make a choice); System.out.println("1) Add House"); System.out.println("2) Show Houses"); System.out.println("3) Exit"); int choice = sc.nextInt();
Then I have a switch for all of the three cases. I keep the scanner open, so Java can get the user input (house = for sale or sold, price = ... etc). If the user chose option 1, and all information needed is inputted and scanned, the House will be written to the file (which looks like what I typed above).
For this, I use try (PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("Makelaar.txt", false)))). This works perfectly (at least so it seems.)
If the user chose option 1, and all requirements are inputted and scanned, the Houses will be read (scanner) from the file and outputted. For this I use the same Scanner sc. This also works perfectly (so it seems atleast).
My problem is as follows: If a House has been added, I can only read the House(s) which were already in the file. Let's say I have added 2 houses, and there were from the start 3 houses. If option 2 is chosen, the first 3 houses will be scanned perfectly. An exception will be caught for the remaining 2 (just added) Houses. How can I solve this? I tried to close the Scanner, and reopening it, but apparently Java doesn't agree with this
I have a JTable with the model " Names " , " Quantity " and " Unit " .
I'm coding a program where you get the ingredients names.
So i need to get the whole row of one column and String it all up together,because i need to store it in mySql and i have already set it all as String.
how i can do this ?
My code are as follows :
JTable Code:
DefaultTableModel model = (DefaultTableModel)table.getModel(); if(!txtQty.getText().trim().equals("")){ model.addRow(new Object[]{ingCB.getSelectedItem().toString(),txtQty.getText(),unitCB.getSelectedItem().toString()}); }else{ JOptionPane.showMessageDialog(null,"*Quantity field left blank"); }
Getting the values and for storing :
for(int i = 1; i<= i ; i++){ ingredients = table.getName(); }
This is for loop is wrong and it does not work because i have a constructor to take in Ingredients but because it is inside the loop, it cannot take it in.
i have to write more than 100000 rows in a excel sheet (file size more than 20 MB) via java.
when i use XSSF, i am getting below Error.
java.lang.OutOfMemoryError: Java heap space at org.apache.xmlbeans.impl.store.Saver$TextSaver.resize(Saver.java:1592) at org.apache.xmlbeans.impl.store.Saver$TextSaver.preEmit(Saver.java:1223) at org.apache.xmlbeans.impl.store.Saver$TextSaver.emit(Saver.java:1144)
[Code]....
when i use HSSF , i am getting the below Error. java.lang.OutOfMemoryError: Java heap space
I have tried increasing the java heap size , by giving upto -Xms1500m -Xmx2048m
How can I get id from db table for each column values with java or oracle query? I did get before each column content from file and now i need get the id of this column values from db. I read csv files from folder and then load the data from these files into subfolder, and here with line li = line.split(","); I get the values that i have in csv file and split them and become in li the value name, and then in else block i create a P objekt where i set this values from csv files, and with [I]p.setLid(li); I set the value for all valuenames, and then get these valuenames in separate column with other content from this csv.
My question is, i need to do this with db, and write these csv file values to the table in db (it will be done with another java class), what i need, that to write the ids of these values into the table in db, instead of valuename, and while there is no ids for valuenames in csv files, i need to get the id from the table in db where these are already listed with sequences, and i don't know how can i write in data table the id of this valuenames and other content, this data table should contain the ids of valuenames timestamp values and the ids of the csv files name, i don't know how to do this with the ids, i must get the ids from the db table and then set these on [I]p.setLid(li); where i set early the valuenames, instead of valuenames i should set ids, that will set ids automatically for all these valuenames.
Java Code:
try { while ((line = br.readLine()) != null) { if (lc == 0) { li = line.split(",");
[Code] ....
with
Java Code : li = line.split(","); mh_sh_highlight_all('java');
I got the values that then will be given to [I]p.setLid(li); and iterate, but now i want to get id from the table in db where this values stored with id instead of this column values, how can i do it?
Recently I discovered power of Java, I'm coming from Perl, Python world so I'm at very beginning. I have firm understanding of OOP and I'm ready for new challenges. I have question regarding writing to database performance and theory.
Basically as my personal project I'm trying to write some small program or addon which will enable me to write concurrently to database. Let's say that I have some software and that has FIFO output to database in single stream, but since the output interface is not fast enough congestion can occur if the input to the system is high.
I would like to extend that software with addon which will take that one output stream and create 2,3,4 concurrent input streams towards database. API from that software is provided so I can redirect output to third-party extensions and apps.
How to read the excel sheet data and validate that null values are inserted or columns data exceeded with respected to header.and these validated data should be stored into 3 different tables... My requirement is college data excel sheet with combination of all groups like mba,mca,and etc...then re ad the data and find the groups then
1. give entry in the UP_LOAD_DATA_HIST table with this excel data uploading with this user and this date, 2. find the group of the department and save data into CATAGIRY_TBL. 3. Finally save the All data into the students table.
Recently we updated out database and we changed our tables' and columns' names, I'm developing an adf application with EJB3.0 the question is that the new column names start with a number (eg. 001U_ID), its a kind of encoding the names of the tables so no one can modify the values.
When I create a query on the table it is throwing an exception:
Caused by: com.microsoft.sqlserver.jdbc.SQLServerException: Incorrect syntax near 'U_ID'.
I think the problem is that the EJB3.0 doesn't recognize column names starting with a number!!! What can I do to solve this issue?
I'm new to Methods and do not really know how to write a method header. What would an appropriate header look like for the following instance? getFilename: This method takes no parameters. It asks the user for a filename. If that file exists, it returns the filename. If it does not exist, it asks the user for another filename. It continues to ask for filenames until the user gives the name of a file that exists.
Also, how would I make a return tag for this and call it into the main method.
In Java® identifiers, you are allowed letters and numbers (also _ $£¢€ etc, but you should avoid them in normal identifiers). So you cannot have spaces. You cannot write public class Hello World because the javac tool will see World as a separate identifier and not understand what it means and will fail to compile the code. You must write public class HelloWorld instead. And because the class is labelled public you must call the source file Hello World. java. Since you can't have two classes with the same [fully‑qualified] name, you cannot write two public classes in the same source file.
“What about names of source files?” somebody will ask. Well, some file systems will permit spaces in file names; ext4 will and I suspect so will NTFS. Can you write file names with spaces in? You would have to have a different name of the class inside the file, because you can't have spaces, and you therefore cannot make the class public, but maybe you can write a package‑private class with a different name.
On ext4, you have to write out the name of the file and the shell will interpret the space as meaning there are two different file, so you have to escape the space.
campbell@campbellsComputer:~/java$ gedit My First Class.java // My First Class.java class Foo { public static void main(String... args) { System.out.println("Hello, World!"); } } campbell@campbellsComputer:~/java$ javac My First Class.java campbell@campbellsComputer:~/java$ java Foo
I'm new to Methods and do not really know how to write a method header. What would an appropriate header look like for the following instance? getFilename: This method takes no parameters. It asks the user for a filename. If that file exists, it returns the filename. If it does not exist, it asks the user for another filename. It continues to ask for filenames until the user gives the name of a file that exists.
Also, how would I make a return tag for this and call it into the main method.
Java Code: import jxl.read.biff.BiffException; import java.io.*; import java.util.*; import jxl.*; import jxl.write.*; public class MainProgram{ public static void main(String[]args){ try{ Workbook workbook = Workbook.getWorkbook(new File("myfile.xls"));
[Code]...
Not sure why this code isnt working for me, it makes an empty excel file called output, but never copies the contents in "myfile" to that output file. I have Excel 2010 but I saved both of them as 97-2003 workbooks. Am I missing something? Do you have to go cell by cell to copy an excel file with JXL?
I'm making a program that will read the file and put the numbers in a list of int arrays and names in another list of strings. In my program i created two classes. One will receive the numbers and the other will receive the names. But i only can read the numbers! How can I read everything and separate into two different lists?
try( BufferedReader br = new BufferedReader( new FileReader( jFileChooser1.getSelectedFile().getAbsolutePath() ) ) ) { hist = new Historic();//Will recieve the array of numbers. while( br.ready() ) { int line[] = new int[ 7 ];
I need to get excel file into jtable . I'm searching for this problem for 1 weak and no results . I downloaded hssf packages and didn't make a change in reading...
I have a JSP code which will open the contents of a excel file.
Now i need this contents of the excel file to be added dynamically to a table in the sameJSP. How to proceed.At the maximum 10 rows can be added dynamically.
Assuming i have a table in JSP which has heading first name,last name,DOB and Gender. After opening the excel through JSP the contents needs to be iterated and added to the columns mentioned.
i don't have good grip in java, basically i am a software Tester and rightnow i am automating my application with Selenium (Testing Tool) so i need to write a script in java, so far i Worked with QTP for the same but in that its really easy to Data Driven test with Excel but here i am facing lots of problem. how to read/Write data from excel with java. how can i create input dialog box (like prompt in jscript) ?
i have a folder which contains two types of files (for eg: .csv and .tiff) with same names like, abc.csv and abc.tiff.How to compare the list of files with same names while ignoring their extensions.And my second task is to copy the content from csv file and i have to use that name as file name of .tiff file(Ex: if i have a1 as content in csv file, i have to change .tiff file name from abc.tiff to a1.tiff)
What i basically do is that i read the information of what course that needs to be updated with a new course date and then i log into the wordpress page and navigate to the course and add the date.
I need the java program to be able to do these following actions.
1. Open a webpage
2. write to a form
3. click a button
4. search for a text on screen
5. click on a specific place on the screen/click on a link
With Apache POI it is possible to password protect an excel file. PFB for the code. But it is working with XLSX extension [2010 Excel format], But not with XLS [2003 Excel format].how to accomplish the same
