Compare Folders Java

When working with multiple folders, it is essential to compare their contents for consistency, detect changes, or spot discrepancies between different versions of files. In this tutorial, we’ll walk through how to compare two folders in Java. The result of the comparison will be exported as an HTML report, where color-coded differences will visually highlight the changes between the directories.

Why Compare the Folders?

There are several reasons why you might want to compare folders:

  • Version Control: Check for file changes or additions in backup or deployment folders.
  • Backup Validation: Ensure that files in two directories match to avoid data loss.
  • File Synchronization: Detect if all files are correctly synced between local and remote directories.

By comparing folders in Java, you can quickly identify file discrepancies and take necessary actions such as copying, deleting, or updating files.

Comparing Folders - Java API Configuration

You can compare folders or directories easily by installing Conholdate.Total for Java on your end. Just copy-paste the Maven configurations below in the pom.xml file of your application:

<dependency>
<groupId>com.conholdate</groupId>
<artifactId>conholdate-total</artifactId>
<version>24.8</version>
<type>pom</type>
</dependency>

Compare Folders in Java

The following steps elaborate how to compare folders in Java:

  • Setting up CompareOptions: The CompareOptions object is configured to enable directory-level comparison by setting a boolean value.

  • Using Comparer Class: The Comparer is initialized with the path to the first folder. The try-with-resources statement ensures the comparer is automatically closed after the operation.

  • Adding the Second Folder: Specify the second directory by using the add method.

  • Generating the HTML Report: The compare() method compares the contents of both folders and saves the results in an HTML file.

The sample code below shows how to compare folders in Java:

Understanding the HTML Report

The HTML output provides a clear visual representation of the differences between the two directories. The files are color-coded as follows:

  • Red: Files that are deleted from folder2 but present in folder1.
  • Blue: Files that are either modified or newly added in folder2.
  • Black: Files that are identical in both folder1 and folder2.

This approach simplifies the folder comparison process, enabling developers to quickly identify changes or missing files.

Free Evaluation License

You can request free temporary license to test and evaluate several features offered the API, without any evaluation limitations.

Summing Up

Comparing folders in Java is a powerful way to ensure the integrity and synchronization of file directories. By using the Comparer class and generating an HTML report, you can easily track differences between two folders and visually detect file modifications, deletions, and unmodified files. This is particularly useful for version control, backups, and file synchronization tasks. If you need to discuss any of your queries, please feel free to reach out to us at forum.

See Also