Eclipse/java code completion not working

java

prompt-engineering

best-practices

content-assist

byNikita Barsukov·Nov 3, 2024

To bring back the much-needed Java code completion in Eclipse:

Confirm the project’s build path: Right-click project > Properties > Java Build Path > Libraries.
Ensure the project uses an apt JRE: in Libraries tab, click Add Library... > JRE System Library if missing.
Perform a clean build: Project > Clean (You never know, a good clean might just do the trick! 🧹).
Refresh the project (F5).
Check your content assist settings: Window > Preferences > Java > Editor > Content Assist (Just to make sure it's not hiding from you 😉).
Be brave and restart Eclipse with the -clean flag if needed.

Immediate content assist activation:

Window > Preferences > Java > Editor > Content Assist > Advanced

Simply select all proposals, apply, and close. Magic ensues! (Nothing up my sleeves, I promise! 🎩🐇)

In-depth solution: Cache cleaning and shortcuts

Sometimes, all you need is a good spring cleaning. To do this for Eclipse:

Close the program.
Head to your workspace directory.
Delete the naughty files *.index and savedIndexNames.txt in workspace/.metadata/.plugins/org.eclipse.jdt.core.
Restart Eclipse. And voilà!

// Now, code completion is swift
System.out.println("Hello, World!"); // And it speaks too! 🌎

To tackle the infamous keyboard shortcuts conflicts, review Key settings in Eclipse:

Window > Preferences > General > Keys

Perform slight tweaks if any binding clashes with the default Ctrl + Space for content assist. Harmony restored! 🕊️

Tailoring the content assist: Prioritization and optimization

In a move towards efficiency, we can prioritize the types and templates you frequently use:

Preferences > Java > Editor > Content Assist > Advanced

Select:

Other Java Proposals (Other, but not unimportant!)
SWT Template Proposals (Love me some templates!)
Template Proposals
Type Proposals (Type away, my friend!)

Now, remove any superfluous type filters to streamline your code suggestion process. More relevant proposals shall now await your command!

Quick terminal solutions: Eclipse safe mode and keyboard switching

You can wake up your content assist with auto-activation triggers:

Window > Preferences > Java > Editor > Content Assist

Set 'Auto activation triggers for Java' to 'abcdefghijklmnopqrstuvwxyz_'. This will make your content assist on-call and ready to serve you. Efficiency FTW! 🎯

If you're a friendly Linux user, and there's a conflict with IBus (Ah, the joys of Linux! 🐧) that Eclipse has integrated, adjust this setting:

IBus Preferences > Input Method

Simply create a different shortcut that doesn’t overlap with Eclipse's content assist shortcuts. You've got the power! 💪

System-wide considerations: Permissions and third-party plugins

Be aware of potential interference from third-party plugins:

eclipse -clean -safeMode

This command runs Eclipse sans any third-party extensions. It's Eclipse in its purest form! (Just try not to blind yourself with its radiant light! 😎)

Special mention to OS-specific issues that might affect Eclipse. For instance, file permissions being too strict or antivirus software being too zealous.