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Handle Excel filesTag(s): IO JDBC Open Source


There are many solutions to read or write Excel spreadsheets from Java. This HowTo is only about OpenSource (and free) solutions.

JDBC-ODBC Excel driver

This solution lets you access your Excel worksheet with SQL SELECT statement. The required ODBC driver is included in a regular Windows installation and the JDBC-ODBC bridge is used to access the Excel DSN.

See this HowTo for an example.

JExcel

Java Excel API is a java API enabling developers to read, write, and modify Excel spreadsheets dynamically. Any operating system which can run a Java virtual machine can both process and deliver Excel spreadsheets. One nice thing about JExcelApi is that it has no dependencies on any third party libraries.

Example : output an Excel file from a Servlet

import java.io.IOException;
import java.io.OutputStream;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import jxl.Workbook;
import jxl.write.Label;
import jxl.write.WritableSheet;
import jxl.write.WritableWorkbook;

public class Sample extends HttpServlet {
 public void doGet
   (HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
  OutputStream out = null;
  try {
   response.setContentType("application/vnd.ms-excel");
   response.setHeader
     ("Content-Disposition", "attachment; filename=sampleName.xls");
   WritableWorkbook w = 
     Workbook.createWorkbook(response.getOutputStream());
   WritableSheet s = w.createSheet("Demo", 0);
   s.addCell(new Label(0, 0, "Hello World"));
   w.write();
   w.close();
  } 
  catch (Exception e){
   throw new ServletException("Exception in Excel Sample Servlet", e);
  } 
  finally{
   if (out != null)
    out.close();
  }
 }
}

See http://jexcelapi.sourceforge.net/

POI

The POI project consists of APIs for manipulating various file formats based upon Microsoft's OLE 2 Compound Document format using pure Java. POI is your Java Excel solution as well as your Java Word solution.

HSSF is the POI Project's pure Java implementation of the Excel '97(-2002) file format and it provides a way to read spreadsheets create, modify, read and write XLS spreadsheets. Latest POI version seems to support the .XLSX format.

Since it's Jakarta project, POI has a dependencies with other JARs (commons,log4j,etc...).

Example : create an Excel file

HSSFWorkbook wb = new HSSFWorkbook();
HSSFSheet sheet = wb.createSheet("new sheet");

HSSFRow row = sheet.createRow((short)0);
row.createCell((short)0).setCellValue("HelloWorld");

FileOutputStream fileOut = new FileOutputStream("workbook.xls");
wb.write(fileOut);
fileOut.close();

The name was originally an acronym for "Poor Obfuscation Implementation" (ref: Wikipedia).

See http://jakarta.apache.org/poi/

JXLS

jXLS is a project that allows creation of extremely complex Excel reports just in several lines of code. It is based on Jakarta POI.

With jXLS, all you need is to create XLS template file with all required formatting, formulas etc using specific notation to indicate placement of data and then write a couple lines of code to invoke jXLS engine passing XLS template and the exported data as parameters.

Example :
The XLS Template

Employees               
Name                Age             Payment             Bonus
${employee.name}    ${employee.age} ${employee.payment} ${employee.bonus}
                                    $[SUM(@employee.payment@)]  

with the code

Collection staff = new HashSet();
staff.add(new Employee("Derek", 35, 3000, 0.30));
staff.add(new Employee("Elsa", 28, 1500, 0.15));
Map beans = new HashMap();
beans.put("employee", staff);
XLSTransformer transformer = new XLSTransformer();
transformer.transformXLS(templateFileName, beans, destFileName);
gives the result
Employees               
Name    Age     Payment Bonus
Derek   35      3000    30,00%
Else    28      1500    15,00%
                4500   
Reading values from an XLS with jXLS is very simple. Suppose we have a worksheet with policy numbers in the first column. We read and process them one by one.
import java.io.File;

import jxl.Cell;
import jxl.Sheet;
import jxl.Workbook;


   public void doit() throws Exception {
        Workbook workbook = Workbook.getWorkbook(new File("policies.xls"));
        Sheet sheet = workbook.getSheet(0);
        Cell policies[] = sheet.getColumn(0);
        for (Cell policy : policies) {
           String nopolicy = policy.getContents();
           //  do something : process(nopolicy);
        }
    }

See http://jxls.sourceforge.net/

xlSQL

xlSQL is a JDBC Driver for Excel and CSV data sources. Documents can be read and written with SQL as if they were tables in a database.

You can export XLS to XML or SQL INSERT statements. xlSQL includes its own "zero-admin" mySQL database. The documentation is minimal at this time.

See http://xlsql.sourceforge.net/

JCOM

JCOM is a Java to COM bridge library. With JCOM you can call a COM object from Java as if it were a Java object without having to deal with the internals of JNI. The documentation is minimal (in Japanese!).

Example :

import jp.ne.so_net.ga2.no_ji.jcom.excel8.*;
import jp.ne.so_net.ga2.no_ji.jcom.*;
import java.io.File;
import java.util.Date;

class TestExcel {
 public static void main(String[] args) throws Exception {
   ReleaseManager rm = new ReleaseManager();
   try {
    System.out.println("EXCEL startup...");
    // if already started, open new window
    ExcelApplication excel = new ExcelApplication(rm);
    excel.Visible(true);
    // display any information
    System.out.println("Version="+excel.Version());
    System.out.println("UserName="+excel.UserName());
    System.out.println("Caption="+excel.Caption());
    System.out.println("Value="+excel.Value());

    ExcelWorkbooks xlBooks = excel.Workbooks();
    ExcelWorkbook xlBook = xlBooks.Add();   // create new book

    // enumurate all files
    System.out.println
      ("set infomation of files in current directory to cell ...");
    ExcelWorksheets xlSheets = xlBook.Worksheets();
    ExcelWorksheet xlSheet = xlSheets.Item(1);
    ExcelRange xlRange = xlSheet.Cells();

    xlRange.Item(1,1).Value("filename" );
    xlRange.Item(2,1).Value("size" );
    xlRange.Item(3,1).Value("last modified time");
    xlRange.Item(4,1).Value("is directory");
    xlRange.Item(5,1).Value("is file");
    xlRange.Item(6,1).Value("can read");
    xlRange.Item(7,1).Value("can write");

    File path = new File("./");
    String[] filenames = path.list();
    for(int i=0; i<filenames.length; i++) {
        File file = new File(filenames[i]);
        System.out.println(file);
        xlRange.Item(1,i+2).Value( file.getName() );
        xlRange.Item(2,i+2).Value( (int)file.length() );
        xlRange.Item(3,i+2).Value( new Date(file.lastModified()) ); 
        xlRange.Item(4,i+2).Value( file.isDirectory()?"Yes":"No" );
        xlRange.Item(5,i+2).Value( file.isFile()?"Yes":"No" );   
        xlRange.Item(6,i+2).Value( file.canRead()?"Yes":"No" );  
        xlRange.Item(7,i+2).Value( file.canWrite()?"Yes":"No" ); 
    }
    String expression = "=Sum(B2:B"+(filenames.length+1)+")";
    System.out.println
       ("embed equation, calculate sum of filesize: "+expression);
    xlRange.Item(1,filenames.length+2).Value("sum");
    xlRange.Item(2,filenames.length+2).Formula(expression);
    xlRange.Columns().AutoFit();    // fit columns

    // comment out, if print out.
    // output default printer.
    //   System.out.println("print out...");
    //   xlSheet.PrintOut();

    // comment out, if book save to file.
    // if no path, save to(My Documents)
    // System.out.println
    //   ("save to file... (My Documents)\\testExcel.xls");
    // xlBook.SaveAs("testExcel.xls");

    xlBook.Close(false,null,false);
    excel.Quit();

    System.out.println("thank you .");
   }
   catch(Exception e) { e.printStackTrace(); }
   finally { rm.release(); }
  }
}

See http://sourceforge.net/projects/jcom

See also this HowTo for an alternative package to access a COM package from Java.

OpenXLS Java Spreadsheet SDK

OpenXLS claims that it has the best compatibility with complex Excel files and able to handle any kind of Excel file out there without corrupting it. This open source effort is the result of over 6 years of development into it.

See http://www.extentech.com/estore/product_detail.jsp?product_group_id=228

Example (extract 3 images from a workbook, create a new workbook with them) :

doit("testImages.xls","Sheet1");

...

void doit(String finpath, String sheetname){    
  System.out.println("Begin parsing: " + workingdir + finpath);
  WorkBookHandle tbo = new WorkBookHandle(workingdir + finpath);

  try{
    sheet = tbo.getWorkSheet(sheetname);
    // read images from sheet 1 -- .gif, .png, .jpg
    ImageHandle[] extracted = sheet.getImages();
    // extract and output images
    for(int t=0;t<extracted.length;t++) {
      System.out.println("Successfully extracted: " 
         + workingdir + "testImageOut_" 
         + extracted[t].getName()+"."
         +extracted[t].getType());
      FileOutputStream outimg = new FileOutputStream
         (workingdir + extracted[t].getName()+"."
         +extracted[t].getType());
      extracted[t].write(outimg);
      outimg.flush();
      outimg.close();
    }

    tbo = new WorkBookHandle();
    sheet = tbo.getWorkSheet("Sheet1");
    CellHandle a1 = sheet.add
       ("New workbook with 3 images: a gif, a jpg, and a png", "A1");

    // get gif image input stream
    FileInputStream fin = new FileInputStream
       (workingdir + "testImages.gif");

    // add to sheet
    ImageHandle giffy = new ImageHandle(fin, sheet);

    // set picture size and location in sheet
    giffy.setBounds(100, 100, 400, 200);
    giffy.setName("giffy");
    sheet.insertImage(giffy);

    // add to sheet
    for(int x=0;x<100;x++) {
      fin = new FileInputStream(workingdir + "testImages.png");
      ImageHandle jpgy = new ImageHandle(fin, sheet);
      jpgy.setName("heart" + x);
      // set the random x/y coords of picture
      int ix = Math.round((float)((x * (Math.random()*10))));
      jpgy.setX(100 +  ix);
      ix = Math.round((float)((x * (Math.random()*10))));
      jpgy.setY(100 + ix);
      sheet.insertImage(jpgy);
    }
    // get png image input stream
    fin = new FileInputStream(workingdir + "testImages.jpg");
    // add to sheet
    ImageHandle pngy = new ImageHandle(fin, sheet);
    // set just the x/y coords of picture
    pngy.setX(10);
    pngy.setY(200);
    sheet.insertImage(pngy);
  }
  catch(Exception e){
    System.err.println("testImages failed: " + e.toString());
  }
  testWrite(tbo, workingdir + "testImagesOut.xls");
  WorkBookHandle newbook = new WorkBookHandle
     (workingdir + "testImagesOut.xls",0);
  System.out.println("Successfully read: " + newbook);
}

public void testWrite(WorkBookHandle b, String fout){
  try{
    java.io.File f = new java.io.File(fout);
    FileOutputStream fos = new FileOutputStream(f);
    BufferedOutputStream bbout = new BufferedOutputStream(fos);
    bbout.write(b.getBytes());
    bbout.flush();
    fos.close();
  } 
  catch (java.io.IOException e){
    System.err.println("IOException in Tester.  "+e);
  }  
}

See also this HowTo for a way to create a simple XLS without any additional library.



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