Eclipse Code Editing

Edit files in Eclipse workspace projects using the eclipse-coder MCP tools. These tools keep Eclipse editors synchronized, trigger incremental compilation, and maintain local history for undo.

Available Editing Tools

• applyPatch — Apply a unified diff patch. Supports multiple hunks with fuzzy context matching. Best for multi-location edits. Set showDialog=true to let the user review via Eclipse's Apply Patch wizard.
• replaceString — Find and replace exact string. Good for single targeted changes. Optionally scoped to a line range.
• insertIntoFile — Insert content before a specific line (1-based).
• createFile — Create a new file and open it in the editor.
• deleteFile — Delete a file from the project.
• deleteLinesInFile — Delete a range of lines (1-based, inclusive).
• replaceFileContent — Replace entire file content.
• formatFile — Format a Java file using Eclipse's formatter (Ctrl+Shift+F).
• organizeImports — Organize imports in a Java file (Ctrl+Shift+O).
• organizeImportsInPackage — Organize imports across all files in a package.
• undoEdit — Restore a file from Eclipse's local history.

Refactoring Tools

For Java files, prefer refactoring tools over manual rename/move — they update all references:

• refactorRenameJavaType — Rename class/interface/enum with workspace-wide reference updates.
• refactorMoveJavaType — Move type to different package with reference updates.
• refactorRenamePackage — Rename package with all declaration and reference updates.
• moveResource — Move file/folder (no reference updates — use refactorMoveJavaType for Java).

Workflow

1. Read efficiently — Don't dump entire files:
   • getClassOutline → understand class structure (~30 lines vs ~300)
   • getMethodSource → read only the methods you need to edit
   • getFilteredSource → full source with non-relevant methods collapsed
   • readProjectResource with excludeImports=true → skip import noise
   • Reserve getSource / full readProjectResource for small files
2. Edit using the appropriate tool (see above)
3. Verify with getCompilationErrors to check for problems
4. Clean up with organizeImports if new types were referenced, formatFile for conventions

Tips

• For multi-hunk changes, prefer applyPatch over multiple replaceString calls
• replaceString requires exact whitespace matching — if it fails, try applyPatch instead
• All tools require projectName (Eclipse project name) and filePath (relative to project root, without project name)
• Use getProjectLayout with scopePath and maxDepth to navigate large projects
• Line numbers from getClassOutline, getMethodSource, and getFilteredSource are always accurate for replaceString line ranges and applyPatch hunks