Lambda suggestions in Eclipse like IntelliJ does

Question

When in IntelliJ you enter some code like this :

Runnable cronTask = new Runnable() {
   @Override
   public void run() {
      // do something
   }
};

IntelliJ will automatically suggest that this will be better when using a lambda expression. And you have the option to do an automatic conversion to

Runnable cronTask = () -> {
   // do something
};

Is something like this possible in Eclipse ? Maybe with some kind of plugin ? I want Eclipse to give me warnings of where a lambda expression might be a better solution. And if possible also suggest the correct fix.

Answer 1

To the best of my knowledge, there is no way to make Eclipse show compiler warnings where lambda expressions are a better alternative. Nevertheless, there is a nice feature that takes care of the automatic conversion you requested.

Right-click on any project or Java file, and select Source -> Clean Up... In the window that appears, select Use custom profile , and click Configure... In the Code Style tab, enable Convert functional interface instances , and make sure Use lambda where possible is selected, as shown in the screenshot below:

Validate and run the clean up. This feature alongside the manual Quick assist suggested by Timothy Truckle in the comments will hopefully cover most of your needs.

Answer 2

Once you have "Use lambda when possible", you can now (Eclipse 2020.03) clean them up

A new clean up has been added that simplifies the lambda expression and the method reference syntax and is enabled only for Java 8 and higher.

The clean up:

• removes parenthesis for a single untyped parameter,
• return statement for a single expression and
• brackets for a single statement.

It replaces a lambda expression by a creation or a method reference when possible.

To select the clean up, invoke Source > Clean Up... , use a custom profile, and on the Configure... dialog select Simplify lambda expression and method reference syntax on the Code Style tab.

For the given code:

You get this after the clean up: