How to Compare Text, Word, PDF with Java or Kotlin Leave feedback

After going through this article, you will be able to compare text files, Word files, PDF files, and other documents in Java-based applications. By using this feature, we can compare invoices, contracts, presentations, AutoCAD designs, price lists, or programming files. We will also have opportunity to highlight the identified changes and have the option to either accept or reject any change. You can even build our own document comparison tool similar to the one launched by GroupDocs, using the document comparison API for Java.

As a pre-requisite, you may get GroupDocs.Comparison for Java from the downloads section. Also, you can easily add Comparison API to your Maven, Gradle or Kotlin DSL project fallowing installation instructions.

Steps below will show you how to compare any two Word documents in just a few lines of Java or Kotlin code. As a result, you will get the resultant document that will be highlighting the identified changes.

• Initialize the Comparer object with the source document path.
• Add the second document to compare using the add method of Comparer object.
• Call the compare method to get the result of the comparison. The compare method takes the name of the output document as a parameter.

Here is an example of the resultant Word document generated by the code above. It contains the highlighted differences of the compared documents. The deleted content will be marked in Red, added content will be displayed in Blue, however, Green shows the modified content.

You can similarly pass the document as a stream to the Comparer class to get it compared with the second document.

Using streams can be useful to compare documents without saving them on a disk

After comparing documents, you have the option to either accept or reject any change. Below you can see the example of accepting and rejecting the changes alternatively. You may display each change one by one with the similar code and take your decisions to accept/reject each change according to your requirement.

More details about accepting and rejecting changes can be found in documentation

Using the Comparer class, we can also compare any text files. Below is the similar code for comparing two text files in Java or Kotlin. Steps are exactly the same as comparing any other two documents:

• Initialize the Comparer object with the source text file.
• Add the second file using the add method of Comparer object.
• Call the compare method to get the result of the comparison.

Here is the source, target and output text files that shows the comparison result of matching two text files using the code above.

Here is the list of all file’s formats supported by GroupDocs.Comparison for Java

We can compare PDF files using the same code, just by changing the file extensions to .pdf.

Here is a result of comparing two PDF files in Java or Kotlin.

Many other open-source examples are available at GitHub Repository. You may download and quickly run examples using the getting started guide. In case of any questions, look at the documentation or reach us at any time on the forum.

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