Apache POI

Apache POI supports the creation and manipulation of Microsoft Office file formats, principally files created with Excel, Word, and PowerPoint.

Apache POI is sadly lumbered with having to support these six formats, which it calls HSSF and XSSF for Excel, HWPF and XWPF for Word, and HSLF and XSLF for PowerPoint. The 'H' prefix is for the OLE formats (and stands for 'Horrible'), while the 'X' is for XML.

All of this complicates coding of course, since you have to decide whether to deal with all the formats, or just OOXML. To be fair, Apache POI hides some of the differences, as illustrated in the Extractor.java and GetThaiData.java examples.

More information on Apache POI:

• Overviews: here, here, here / here, and here
• API Components, which links to lots of examples via the list of applications.
• The examples are also available here, which leads to subdirectories for Excel, Word, and PowerPoint.
• The API Docs
• The Download page

The rest of this page lists my examples, which I've divided into four groups: 'General', 'Excel', 'Word', and 'PowerPoint'. The 'General' code works with all formats, while the other three focus on the specified application. Within each group, there's usually two examples, one for reading a file, and one for generating a file.

General

• Extractor.java prints the text extracted from the any Excel, Word, or PowerPoint file.
• POIUtils.java contains utilities related to detecting a file's type (by using Apache Tika), file name manipulation, and functions for loading and saving images.

Excel

• GetThaiData.java reads the province names and their three-letter codes from Thailand.xlsx.
• WriteSheet.java generates a single sheet Excel file called WriteSheet.xlsx, consisting of six rows of data including a header line.
• SheetToWordTable.java converts readings.xlsx into a table that's stored in a DOCX file.

Other links for programming Excel with POI: here, here, here, here, here.

Word

• ReadParagraphs.java reads in sample.docx, and prints all the paragraphs.
• WriteDoc.java generates a DOCX file about "Hamlet", including an image taken from hamlet.png.

Other links for programming Word with POI: here, here, here, and here.

PowerPoint

• ReadSlidesText.java prints all of the text found in prelims.pptx.
• WriteSlides.java creates a series of slides, including images from coeHeader.png and bench.jpg, and stores them in a PPTX file. The 'title and content' layout is modified to use a logo and a blue line.
• SlidesToImages.java generates a series of PNG files from prelims.pptx, one image for each slide.

Other links for programming PowerPoint with POI: here, here, here.

Other Downloads and Links

• Batch files to easily compile and run my code: compile.bat and run.bat
   
  
• All of my examples in one zipped file (1.47 MB)
   
  
• My copies of the libraries (24 MB). Unbelievably, this very large zip file only contains the Apache POI JARs necessary to run my examples, although I found it necessary to add log4j-core-2.18.0.jar, slf4j-simple-1.6.2.jar, and tika-core-2.6.0.jar. The logging classes are required to stop POI from issuing warnings when I run the examples from the command line rather than inside an IDE. Apache Tika uses a file's metadata and text to accurately determine its file types. The list of JARs can be split into four broad groups:
   
  
  1. POI: poi-5.2.3.jar, poi-ooxml-5.2.3.jar, poi-ooxml-full-5.2.3.jar, poi-scratchpad-5.2.3.jar;
      
     
  2. Apache Commons: commons-codec-1.15.jar, commons-collections4-4.4.jar, commons-compress-1.21.jar, commons-io-2.11.0.jar, commons-math3-3.6.1.jar
      
     
  3. Logging: log4j-api-2.18.0.jar, log4j-core-2.18.0.jar (added by me), slf4j-api-1.7.36.jar, slf4j-simple-1.6.2.jar (added by me)
      
     
  4. Others: SparseBitSet-1.2.jar, xmlbeans-5.1.1.jar, tika-core-2.6.0.jar (added by me)

  Unzip the file, and place the libs folder in the same directory as the examples and batch files.

• The official libraries come in at a whopping 66 MB when unzipped (for v. 5.2.3), but support everything, such as SVG and PDF creation.