Eclipse Code Analysis

Analyze Java code using Eclipse's JDT (Java Development Tools) infrastructure. These tools provide accurate, compiler-level analysis — not text-based guessing.

Reading Code Efficiently

These tools are designed to minimize context window usage. Follow the outline-first pattern:

1. getClassOutline — Start here. Returns class declaration, field declarations, method signatures (no bodies), and inner types — all with line numbers. A 500-line class becomes ~30 lines. Provide fullyQualifiedClassName. Set includeFields=false to omit fields.

2. getMethodSource — After seeing the outline, read only the methods you need. Accepts comma-separated methodNames (e.g., "save,findById,delete"). Returns source with line numbers. Set includeJavadoc=false to skip doc comments. Use methodSignature to disambiguate overloads (e.g., "String" matches methods with a String parameter).

3. getFilteredSource — Middle ground: returns the full source but collapses methods you don't need to their signatures. Provide methodNames to expand specific methods; all others are shown as one-line signatures with line ranges. Set excludeImports=true (the default) to collapse the import block. Line numbers always match the original file for accurate editing.

4. getSource — Full source dump. Use only for small classes or when you need everything. Prefer the tools above to save context.

5. readProjectResource — Read any file by path. Supports startLine/endLine for ranges, showLineNumbers=true for editing, and excludeImports=true to collapse Java import blocks.

Choosing the Right Tool

Scenario	Tool	Why
Understand class structure	getClassOutline	Signatures only, ~90% smaller
Read 1-3 specific methods	getMethodSource	Surgical reads with line numbers
Read class but focus on 2 methods	getFilteredSource	Full context, collapsed noise
Small class (<100 lines)	getSource	Overhead not worth optimizing
Non-Java file or specific line range	readProjectResource	Works with any file type

Navigation & Understanding

• getTypeHierarchy — Show supertypes, implemented interfaces, and subtypes for a class.
• findReferences — Find all usages of a type, method, or field across the workspace. Essential before renaming or deleting.
• getMethodCallHierarchy — Show callers and callees of a method. Use methodSignature for overloaded methods.
• getJavaDoc — Get JavaDoc for a compilation unit by fully qualified name.

Error Analysis

• getCompilationErrors — Get all compilation errors/warnings. Filter by projectName and severity (ERROR, WARNING, ALL).
• getQuickFixes — Get available quick fixes for errors in a file. Optionally filter by lineNumber.
• getImportSuggestions — Find import candidates for unresolved types.

Project Navigation

• getProjectLayout — File/folder structure. Use scopePath and maxDepth for large projects.
• getProjectProperties — Java version, source folders, output location, natures.
• listProjects — All workspace projects with their natures.
• getProjectDependencies — Maven dependencies for a project.

Search

• fileSearch — Plain text search across workspace files. Filter with fileNamePatterns.
• fileSearchRegExp — Regex search across workspace files.
• findFiles — Find files by glob patterns (e.g., *.xml, pom.xml).

Editor Context

• getCurrentlyOpenedFile — Get the file currently active in the Eclipse editor.
• getEditorSelection — Get the currently selected text/lines in the active editor.

Recommended Workflow

1. Orient: listProjects or getProjectLayout to find what you need
2. Outline: getClassOutline to understand class structure
3. Focus: getMethodSource to read specific methods, or getFilteredSource for full-but-collapsed view
4. Analyze: getTypeHierarchy, findReferences, getMethodCallHierarchy as needed
5. After edits: getCompilationErrors to verify, then getQuickFixes or getImportSuggestions to resolve