How to Create Excel Spreadsheets Using Java

View a Java-generated spreadsheet in Microsoft Excel.

Business users can be particular. While Java's JTable presents data in a tabular form, some users just want to manipulate that data in Microsoft Excel. To satisfy such finicky users, you can generate a CSV file from Java and automatically launch Excel to view the data to keep them happy. The data placed into the CSV file can come from querying a JDBC data source or from parsing some XML files acquired from over your Internet connection, among many other possibilities.

Things You'll Need

• Java Runtime Environment version 6 or above
• Microsoft Excel

Instructions

1. Create a new file in your computer's text editor and save the file with the name Spreadsheet.java.

2. Include the Java I/O class library in the source code by adding the following line at the top of your file: import java.io.*;.

3. Generate your spreadsheet data as a set of lines with comma-separated values:

   public static String generateText() {

   return "1, 2, 3\r\n4, 5, 6\r\n7, 8, 9\r\n";

   }

4. Create a temporary file with a .csv extension to store the spreadsheet data:

   File file = File.createTempFile("test", ".csv");

5. Write the generated data to the file:

   PrintWriter pw = new PrintWriter(file);

   pw.write(text);

   pw.close();

6. Use the Microsoft Windows cmd shell to open the file:

   String[] cmd = new String[] {"cmd", "start", "/c", file.getPath()};

   Runtime.getRuntime().exec(cmd);

7. Save, compile and run your Spreadsheet program to see the generated CSV file in Microsoft Excel.

Tips & Warnings

• You need to use \r\n in the generated text to separate rows in the spreadsheet data. You can also use the println() method of PrintWriter for the same purpose.

• Linux users should replace the launching command with the following: cmd = new String[] {"soffice", file.getPath()};, assuming OpenOffice is available.

References

• Java World: When Runtime.exec() Won't

Resources

• Oracle: The Java Tutorial