Java Migration Tool

Last modified: July 3, 2026

Introduction

The Java Migration Tool (jmt) is a command-line utility that automatically rewrites deprecated and removed Mendix Java API calls.

The tool complements the Update Assistant (Beta) pane: use the pane to identify deprecations, and the CLI to apply the fixes automatically.

Installation

Download the tool from Mendix CDN: https://cdn.mendix.com/mendix-java-migration-tool/jmt-1.0.0.jar

Basic Usage

Run the tool from a command prompt. Use the same Java version that the version of Studio Pro you are migrating to uses. You can find the Java installation path in Studio Pro's preferences.

The following example rewrites all Java files in the javasource/ folder of your app to the target Studio Pro version:

This example assumes:

  • The Java executable is saved to C:\Program Files\Eclipse Adoptium\jdk-21.0.5.11-hotspot\bin\java
  • jmt-1.0.0.jar is saved to the current folder
  • Mendix 11.11.0 is installed at C:\Program Files\Mendix\11.11.0
  • Your app folder is C:\Users\YourName\Mendix\MyApp
"C:\Program Files\Eclipse Adoptium\jdk-21.0.5.11-hotspot\bin\java" -jar jmt-1.0.0.jar rewrite --to-version 11.11 --studio-pro "C:\Program Files\Mendix\11.11.0" --project-root "C:\Users\YourName\Mendix\MyApp"

Replace the paths and version number with the actual values for your installation. For all available commands and options, see Commands and Options.

Commands

Run the tool with java -jar jmt-1.0.0.jar <COMMAND> [OPTIONS].

  • If Java is on your PATH, call java directly. If not, provide the full path to the java executable.
  • Run the command from the folder where you saved jmt-1.0.0.jar, or specify its full path in the command.
Command Description
version Display the tool version
recipes List all available migration recipes
rewrite <PATHS> Rewrite Java files that are in the given paths (files or folders)

Options

Global

  • -h, --help – show usage information

recipes Command

  • -o, --output <FORMAT> – output format: text (default) or json

rewrite Command

  • -t, --to-version <VERSION> – (required) target Studio Pro version, for example 11.2.0
  • -n, --dry-run – preview changes without writing files
  • -o, --output <FORMAT> – output format: text (default) or json
  • -p, --project-root <PATH> – root of the Mendix project. This enables classpath resolution via javasource/, vendorlib/, and userlib/
  • -s, --studio-pro <PATH> – Studio Pro installation folder. This enables Mendix public Java API resolution via the runtime bundles

Examples

Commands

# List available recipes
java -jar jmt-1.0.0.jar recipes

# Apply with full project context for accurate type resolution
java -jar jmt-1.0.0.jar rewrite javasource/ -t 11.2.0 \
  -p /path/to/mendix-project \
  -s "/path/to/Studio Pro 11.2.0"

# Preview changes without writing (dry run)
java -jar jmt-1.0.0.jar rewrite javasource/ -t 11.2.0 -n

# Apply all applicable recipes to the javasource folder
java -jar jmt-1.0.0.jar rewrite javasource/ -t 11.2.0

# Machine-readable output for CI/CD integration
java -jar jmt-1.0.0.jar rewrite javasource/ -t 11.2.0 -o json

Output Formats

Text (default) – human-readable summary:

[REWRITE] Target version: 11.2.0
Applied recipes:
  - Replace IMendixObject.getMember(...) (available from: 10.18)

Changed: javasource/myfirstmodule/actions/MyAction.java
  Replace IMendixObject.getMember(...): 2

Files processed: 1
Files changed: 1
Total changes: 2

JSON – machine-readable, suitable for CI/CD pipelines:

{
  "status": "success",
  "dryRun": false,
  "filesProcessed": 1,
  "filesChanged": 1,
  "totalChanges": 2,
  "files": [
    {
      "file": "javasource/myfirstmodule/actions/MyAction.java",
      "changes": [
        {
          "recipe": "Replace IMendixObject.getMember(IContext, String) with IMendixObject.getMember(String)",
          "count": 2
        }
      ]
    }
  ],
  "warnings": []
}

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