Fix Eclipse Java Code Completion Not Working Issues

Eclipse Java code completion issues in Eclipse 3.4.2 with plugins like EPIC, Clearcase, QuantumDB, and MisterQ typically stem from configuration conflicts or misconfigured build paths. When you encounter “No Default Proposals” and “No completions available” messages while using Ctrl+Space in your eclipse java projects, it indicates that the IDE’s content assist functionality is unable to provide code suggestions, which can severely impact your development productivity.

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Contents

• Understanding Eclipse Code Completion Issues
• Checking Build Path and JDK Configuration
• Verifying Content Assist Settings
• Troubleshooting Plugin Conflicts
• Advanced Solutions for Persistent Issues

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Understanding Eclipse Code Completion Issues

When eclipse java code completion stops working, it’s rarely due to a single cause. The “No completions available” message can appear for several reasons related to your eclipse ide for java configuration. In your specific case with Eclipse 3.4.2 and multiple plugins, the issue likely stems from conflicts between different plugins or incorrect configuration of the Java Development Kit (JDK).

Code completion, also known as content assist, relies on Eclipse’s ability to parse your Java code and understand the context in which you’re typing. When this functionality breaks, it could be because:

1. The IDE cannot locate the proper JDK files
2. There are conflicts between different plugins
3. Your project’s build path is incorrectly configured
4. Content assist settings have been modified
5. The workspace configuration has become corrupted

The good news is that these issues are typically resolvable through systematic troubleshooting. In most cases, you can restore code completion functionality without reinstalling Eclipse.

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Checking Build Path and JDK Configuration

One of the most common causes of code completion failure in eclipse java projects is an improperly configured build path. Eclipse needs to know where your JDK installation is located to provide accurate code suggestions.

Verify JDK Installation

First, ensure you have a compatible JDK installed. Eclipse 3.4.2 works best with JDK 6 or JDK 7. To check your Java installation:

1. Open a command prompt or terminal
2. Type java -version and press Enter
3. Type javac -version and press Enter

Both commands should return version information. If not, install a compatible JDK.

Configure Project Build Path

1. Right-click on your Java project in the Project Explorer
2. Select “Properties” from the context menu
3. Navigate to “Java Build Path” in the left pane
4. Under “Libraries,” check if “JRE System Library” is present
5. If missing, click “Add Library” → “JRE System Library” → “Standard VM”
6. Browse to your JDK installation directory and select it

If you see multiple JRE entries, remove duplicates and ensure only one correct JDK is referenced. The “JRE System Library” should point to your JDK installation, not just the JRE.

Check Project Specific Settings

Sometimes, individual project settings can override workspace defaults:

1. In the Java Build Path properties, verify the “Source” tab
2. Ensure source folders are correctly marked as “Source” (blue folder icon)
3. Check for any excluded folders that might contain relevant Java files

According to JavaSpring, incorrect build path configuration is responsible for approximately 60% of code completion issues in Eclipse. Verifying your JDK configuration is often enough to resolve the problem.

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Verifying Content Assist Settings

Even with a correctly configured build path, eclipse java code completion might not work if Content Assist settings are improperly configured. These settings determine which code suggestions Eclipse provides and when.

Access Content Assist Preferences

1. Go to “Window” → “Preferences” in the Eclipse menu
2. Navigate to “Java” → “Editor” → “Content Assist”
3. Ensure the “Enable auto activation” checkbox is checked

Check Auto-Activation Settings

Auto-activation determines when Eclipse automatically suggests code completion without pressing Ctrl+Space:

1. In Content Assist preferences, look at the “Auto activation triggers for Java” section
2. Ensure that “.” (dot) is listed in the characters field
3. Set “Auto activation delay” to a reasonable value (200ms is a good starting point)

Verify Java Proposals

The “Java Proposals” section controls what kind of suggestions Eclipse provides:

1. Expand the “Advanced” section
2. Make sure “Java” is checked and has appropriate proposals enabled
3. Ensure “Types” and “Methods” are checked, as these are most relevant for code completion

Restore Default Settings

If you suspect the settings have been modified incorrectly:

1. In Preferences, go to “Java” → “Editor” → “Content Assist”
2. Click the “Restore Defaults” button
3. Confirm the action when prompted

As noted in fsauto, restoring default Content Assist options has resolved many “No completions available” issues, especially when the problem appears suddenly after updating preferences.

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Troubleshooting Plugin Conflicts

Given that you have multiple plugins installed (EPIC, Clearcase, QuantumDB, and MisterQ), plugin conflicts are a likely culprit. Some plugins can interfere with Eclipse’s core Java development functionality, particularly code completion.

Systematic Plugin Disabling

The most effective way to identify problematic plugins is to systematically disable them:

1. Close Eclipse completely
2. Navigate to your Eclipse installation directory
3. Find the “plugins” and “features” folders
4. Rename the problematic plugin folders (start with EPIC as it’s specifically mentioned in your question)
5. Restart Eclipse and test code completion
6. If the issue persists, repeat the process with other plugins

According to EPIC Tracker, the EPIC plugin is known to interfere with Java code completion in certain configurations. Disabling it often resolves the “No Default Proposals” error.

Alternative Plugin Management Method

If renaming plugin folders seems too invasive, you can use Eclipse’s built-in plugin management:

1. Go to “Help” → “Software Updates” → “Manage Configuration”
2. Look for your installed plugins in the list
3. Uncheck the plugins one by one, starting with EPIC
4. Restart Eclipse after each change to test code completion

Check for Plugin Updates

Outdated plugins can cause compatibility issues with your Eclipse version:

1. Go to “Help” → “Check for Updates”
2. Install any available updates for your plugins
3. Restart Eclipse and retest code completion

As mentioned in Stack Overflow discussions, library conflicts between different plugins are a common cause of code completion failures, especially when multiple plugins modify Eclipse’s core functionality.

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Advanced Solutions for Persistent Issues

If the previous steps haven’t resolved your eclipse java code completion problem, there are more advanced solutions you can try. These methods involve more drastic measures but often fix even the most stubborn configuration issues.

Create a New Workspace

Sometimes workspace corruption can cause code completion to fail:

1. Close Eclipse completely
2. Navigate to your workspace directory
3. Create a backup copy of the workspace (just in case)
4. Create a new workspace in a different location
5. Import your existing projects into the new workspace
6. Test code completion in the new workspace

According to Stack Overflow, workspace recreation has resolved numerous “No completions available” issues where other methods failed.

Clean and Rebuild Projects

Project-specific corruption can also affect code completion:

1. Right-click on your Java project
2. Select “Clean” from the context menu
3. Check “Clean all projects” and click “OK”
4. After cleaning, right-click the project again
5. Select “Build Project” or “Rebuild Project”

Reinstall Eclipse

As a last resort, you might need to reinstall Eclipse:

1. Uninstall Eclipse completely
2. Delete your Eclipse installation directory
3. Download a fresh copy of Eclipse 3.4.2
4. Install it in a new location
5. Import your projects and reinstall only essential plugins one by one

When reinstalling, be particularly careful with the EPIC plugin, as Epic documentation specifically mentions its potential to interfere with Java code completion.

Consider Eclipse Version Upgrade

Eclipse 3.4.2 is quite old (released in 2009). Consider upgrading to a more recent version of Eclipse that has better plugin compatibility and improved code completion capabilities. Newer versions of Eclipse IDE for Java have significantly enhanced content assist functionality that might resolve your issues permanently.

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Sources

1. JavaSpring Blog — Fixing Eclipse Java code completion issues through build path configuration: https://www.javaspring.net/blog/eclipse-java-code-completion-not-working/
2. Stack Overflow — Troubleshooting Eclipse code completion problems in Java development: https://stackoverflow.com/questions/908489/eclipse-java-code-completion-not-working
3. Stack Overflow — Resolving “No completions available” errors in Eclipse IDE: https://stackoverflow.com/questions/15728776/no-completions-available-strange-eclipse-behavior
4. Stack Overflow — Comprehensive guide to fixing Eclipse autocomplete issues: https://stackoverflow.com/questions/21746294/how-to-fix-eclipse-autocomplete-not-working
5. Stack Overflow — Solutions for Eclipse workspace-related code completion problems: https://stackoverflow.com/questions/21201930/how-to-fix-eclipse-autocomplete-not-working/23494421
6. fsauto Blog — Restoring default Content Assist options to fix completions issues: https://fsauto.blogspot.com/2014/11/solved-how-to-fix-completions-available.html
7. EPIC IDE Tracker — Specific information about EPIC plugin interfering with Java code completion: https://www.epic-ide.org/tracker/code-completion-not-working-in-many-situation.php

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Conclusion

When eclipse java code completion stops working with “No Default Proposals” and “No completions available” messages, it can be frustrating but is usually fixable. The most effective approach is to systematically troubleshoot the issue: first verify your JDK configuration in the build path, then check Content Assist settings, followed by identifying and disabling conflicting plugins like EPIC. If these steps don’t resolve the problem, creating a new workspace or reinstalling Eclipse might be necessary. Remember that Eclipse 3.4.2 is quite old, and upgrading to a more recent version of eclipse ide for java could provide better plugin compatibility and enhanced code completion capabilities. With patience and systematic troubleshooting, you can restore your eclipse java code completion functionality and resume productive development.