How to change an Eclipse default project into a Java project

java

project-properties

java-runtime-environment

maven-projects

byAlex Kataev·Feb 15, 2025

Want to turn a default project into a Java project? Just add some Java nature into it! Here's how:

Close the project in Eclipse.
Edit the .project file in the project's root:

<?xml version="1.0" encoding="UTF-8"?>
<projectDescription>
  <!-- Other parts of the file come before <natures>. Yes, in XML, order matters. Kind of like breakfast comes before lunch. 🙂 -->
  <natures>
    <nature>org.eclipse.jdt.core.javanature</nature>
  </natures>
  <buildSpec>
    <buildCommand>
      <name>org.eclipse.jdt.core.javabuilder</name>
    </buildCommand>
  </buildSpec>
  <!-- XML tag soup continues after </buildSpec>. Better learn to love the diamond brackets. 💎 </>
</projectDescription>

Save and reopen in Eclipse. It's now a bona fide Java project!

Backing up the default project

Don't be reckless with your code if something goes wrong, always backup your project before tinkering with configurations.

Navigate to: Project → Export → Archive File to safely backup your work.

Infusing Java Nature via Project Properties

Comfortably nest in Eclipse's GUI if you're feeling sketchy about manually infusing Java nature.

Right-click on the project → Properties → Project Facets → Check Java. After this, Eclipse shall embrace the project as its own Java child.

Configuring project build path

The project is only half-dressed without the right Java Runtime Environment (JRE).

To get fully prepared, go to: Project → Properties → Java Build Path → Libraries → Add Library... → JRE System Library.

Select your desired JRE or JDK, and now you've got a project fully clad in Java!

Maven projects

Does your project boast a pom.xml? Well then, you're one click away from transforming the project into Java.

Right-click on the project → Maven → Update Project...: with Force Update of Snapshots/Releases checked. Bam! Your Maven project has now donned its Java cap!

Considering Eclipse versions

Like a picky cat, each Eclipse version purrs at its own unique project configuration!

Keep this in mind:

Eclipse 3.3.2 and earlier: specify the project type during checkout
Eclipse 4.9.0 and later: there's a one-stop shop → Project Natures page, to add Java nature all at once.

SVN checkout prowess

Is SVN your bag? Specify project type during checkout → New Project Wizard instead of fiddling with project configurations manually.

Breathe life into old/legacy projects

Got a non-Java, legacy or default project?

You can convert the project to a faceted form by going to: Project → Properties → Project Facets → Click Convert to faceted form..., and then add the Java facet. Don't forget to wave the wand on source (src) and output (bin) folders.

Dealing with potential issues

Changing files manually can invoke the wrath of the Eclipse XML Deity. So remember the following:

Be cautious while editing .project and .classpath.
The Eclipse Interface is a safer bet; XML edits are a last resort.
Clean the slate after meddling with files: Project → Clean.
Hit F5 or Right-click on the project → Refresh, if errant issues rear up.

Remember: Manual conversion might not enable all Java-specific features. Plugins or specific project settings may still require you to manually configure them.

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