JavaLens
Built on Eclipse JDT, this exposes 63 semantic analysis tools that understand Java code the way a compiler does, not just as text. You get type-aware navigation like find_references that distinguishes UserService.save() from every other save() method, find_implementations that follows inheritance chains, and refactoring operations that know about scope and bindings. It answers questions grep can't: where is this field written versus read, what casts to this type, which private methods are unused. Runs as a standalone process with stdio transport, stores JDT indexes in a separate workspace directory to keep your source tree clean. Requires Java 21 runtime but analyzes Java 1.1 through 23. When you need to understand call graphs, dependency cycles, or perform safe renames across a codebase, this gives AI agents compiler-accurate answers instead of pattern matching.
- GitHub stars
- 46
- tools
- 75
- transport
- STDIO
- env vars
- 3
- last updated
- Oct 18, 2026
Tools
75 toolsPublic tool metadata for what this MCP can expose to an agent.
search_symbolsSearch types, methods, fields by glob pattern
Search types, methods, fields by glob pattern
No parameter schema in public metadata yet.
go_to_definitionNavigate to symbol definition
Navigate to symbol definition
No parameter schema in public metadata yet.
find_referencesFind all usages of a symbol
Find all usages of a symbol
No parameter schema in public metadata yet.
find_implementationsFind interface/class implementations
Find interface/class implementations
No parameter schema in public metadata yet.
get_type_hierarchyGet inheritance chain
Get inheritance chain
No parameter schema in public metadata yet.
get_document_symbolsGet all symbols in a file
Get all symbols in a file
No parameter schema in public metadata yet.
get_symbol_infoGet detailed symbol information at position
Get detailed symbol information at position
No parameter schema in public metadata yet.
get_type_at_positionGet type details at cursor
Get type details at cursor
No parameter schema in public metadata yet.
get_method_at_positionGet method details at cursor
Get method details at cursor
No parameter schema in public metadata yet.
get_field_at_positionGet field details at cursor
Get field details at cursor
No parameter schema in public metadata yet.
find_annotation_usagesFind all @Annotation usages
Find all @Annotation usages
No parameter schema in public metadata yet.
find_type_instantiationsFind all new Type() calls
Find all new Type() calls
No parameter schema in public metadata yet.
find_castsFind all (Type) expr casts
Find all (Type) expr casts
No parameter schema in public metadata yet.
find_instanceof_checksFind all x instanceof Type
Find all x instanceof Type
No parameter schema in public metadata yet.
find_throws_declarationsFind all throws Exception in signatures
Find all throws Exception in signatures
No parameter schema in public metadata yet.
find_catch_blocksFind all catch(Exception e) blocks
Find all catch(Exception e) blocks
No parameter schema in public metadata yet.
find_method_referencesFind all Type::method expressions
Find all Type::method expressions
No parameter schema in public metadata yet.
find_type_argumentsFind all List<Type> usages
Find all List<Type> usages
No parameter schema in public metadata yet.
find_reflection_usageFind Class.forName(), Method.invoke(), and other reflection calls
Find Class.forName(), Method.invoke(), and other reflection calls
No parameter schema in public metadata yet.
get_diagnosticsGet compilation errors and warnings
Get compilation errors and warnings
No parameter schema in public metadata yet.
validate_syntaxFast syntax-only validation
Fast syntax-only validation
No parameter schema in public metadata yet.
get_call_hierarchy_incomingFind all callers of a method
Find all callers of a method
No parameter schema in public metadata yet.
get_call_hierarchy_outgoingFind all methods called by a method
Find all methods called by a method
No parameter schema in public metadata yet.
find_field_writesFind where fields are mutated
Find where fields are mutated
No parameter schema in public metadata yet.
find_testsDiscover JUnit/TestNG test methods
Discover JUnit/TestNG test methods
No parameter schema in public metadata yet.
find_unused_codeFind unused private members
Find unused private members
No parameter schema in public metadata yet.
find_unreachable_codeProject-wide dead code — members unreachable from any main method or test, over the whole-program call graph
Project-wide dead code — members unreachable from any main method or test, over the whole-program call graph
No parameter schema in public metadata yet.
find_affected_testsThe tests that exercise a symbol, directly or transitively — the set to run after changing it
The tests that exercise a symbol, directly or transitively — the set to run after changing it
No parameter schema in public metadata yet.
find_possible_bugsDetect null risks, empty catches, resource leaks
Detect null risks, empty catches, resource leaks
No parameter schema in public metadata yet.
get_hover_infoGet documentation/signature for symbol
Get documentation/signature for symbol
No parameter schema in public metadata yet.
get_javadocGet parsed Javadoc
Get parsed Javadoc
No parameter schema in public metadata yet.
get_signature_helpGet method signature at call site
Get method signature at call site
No parameter schema in public metadata yet.
get_enclosing_elementGet containing method/class at position
Get containing method/class at position
No parameter schema in public metadata yet.
analyze_change_impactBlast radius — direct call sites by depth, or the full transitive closure over the project graph (transitive=true)
Blast radius — direct call sites by depth, or the full transitive closure over the project graph (transitive=true)
No parameter schema in public metadata yet.
analyze_data_flowVariable read/write/declaration tracking within a method; opt-in followCalls tracks null/taint facts across calls to sinks
Variable read/write/declaration tracking within a method; opt-in followCalls tracks null/taint facts across calls to sinks
No parameter schema in public metadata yet.
analyze_control_flowBranching, loops, return/throw points, nesting depth
Branching, loops, return/throw points, nesting depth
No parameter schema in public metadata yet.
get_di_registrationsFind Spring DI registrations (@Component, @Bean, @Autowired, @Inject)
Find Spring DI registrations (@Component, @Bean, @Autowired, @Inject)
No parameter schema in public metadata yet.
get_jpa_modelAssembled JPA entity model — tables, id fields, relationships with resolved targets and mappedBy sides
Assembled JPA entity model — tables, id fields, relationships with resolved targets and mappedBy sides
No parameter schema in public metadata yet.
get_http_endpointsAssembled HTTP route table — Spring and JAX-RS paths composed from class prefixes, mapped to handler methods
Assembled HTTP route table — Spring and JAX-RS paths composed from class prefixes, mapped to handler methods
No parameter schema in public metadata yet.
analyze_fileGet imports, types, diagnostics in one call
Get imports, types, diagnostics in one call
No parameter schema in public metadata yet.
analyze_typeGet members, hierarchy, usages, diagnostics
Get members, hierarchy, usages, diagnostics
No parameter schema in public metadata yet.
analyze_methodGet signature, callers, callees, overrides
Get signature, callers, callees, overrides
No parameter schema in public metadata yet.
get_type_usage_summaryGet instantiations, casts, instanceof counts
Get instantiations, casts, instanceof counts
No parameter schema in public metadata yet.
rename_symbolRename across entire project
Rename across entire project
No parameter schema in public metadata yet.
organize_importsSort and clean imports
Sort and clean imports
No parameter schema in public metadata yet.
extract_variableExtract expression to local variable
Extract expression to local variable
No parameter schema in public metadata yet.
extract_methodExtract code block to new method
Extract code block to new method
No parameter schema in public metadata yet.
extract_constantExtract to static final field
Extract to static final field
No parameter schema in public metadata yet.
extract_interfaceCreate interface from class methods
Create interface from class methods
No parameter schema in public metadata yet.
extract_superclassMove a member into a newly created superclass
Move a member into a newly created superclass
No parameter schema in public metadata yet.
inline_variableReplace variable with its initializer
Replace variable with its initializer
No parameter schema in public metadata yet.
inline_methodReplace call with method body
Replace call with method body
No parameter schema in public metadata yet.
change_method_signatureModify params/return, update all callers
Modify params/return, update all callers
No parameter schema in public metadata yet.
convert_anonymous_to_lambdaConvert anonymous class to lambda
Convert anonymous class to lambda
No parameter schema in public metadata yet.
encapsulate_fieldGenerate accessors and rewrite all direct field accesses
Generate accessors and rewrite all direct field accesses
No parameter schema in public metadata yet.
pull_upMove a member into the superclass
Move a member into the superclass
No parameter schema in public metadata yet.
push_downMove a member into the subclasses
Move a member into the subclasses
No parameter schema in public metadata yet.
introduce_parameter_objectBundle a method's parameters into a new class, updating callers
Bundle a method's parameters into a new class, updating callers
No parameter schema in public metadata yet.
move_type_to_new_fileMove a nested type into its own top-level file
Move a nested type into its own top-level file
No parameter schema in public metadata yet.
suggest_importsFind import candidates for unresolved type
Find import candidates for unresolved type
No parameter schema in public metadata yet.
get_quick_fixesList available fixes for problem at position
List available fixes for problem at position
No parameter schema in public metadata yet.
apply_quick_fixApply fix by ID (add import, remove import, add throws, try-catch)
Apply fix by ID (add import, remove import, add throws, try-catch)
No parameter schema in public metadata yet.
apply_cleanupApply one of 10 JDT clean-ups (convert loops, pattern matching, switch expressions, text blocks, ...) and return rewritten source
Apply one of 10 JDT clean-ups (convert loops, pattern matching, switch expressions, text blocks, ...) and return rewritten source
No parameter schema in public metadata yet.
diagnose_and_fixDiagnose a file and return each problem's top quick-fix edits in one call
Diagnose a file and return each problem's top quick-fix edits in one call
No parameter schema in public metadata yet.
get_complexity_metricsCyclomatic/cognitive complexity, LOC per method
Cyclomatic/cognitive complexity, LOC per method
No parameter schema in public metadata yet.
get_dependency_graphPackage/type dependencies as nodes and edges
Package/type dependencies as nodes and edges
No parameter schema in public metadata yet.
find_circular_dependenciesDetect package cycles using Tarjan's SCC algorithm
Detect package cycles using Tarjan's SCC algorithm
No parameter schema in public metadata yet.
find_large_classesFind types exceeding method/field/line count thresholds
Find types exceeding method/field/line count thresholds
No parameter schema in public metadata yet.
find_naming_violationsCheck against Java naming conventions
Check against Java naming conventions
No parameter schema in public metadata yet.
health_checkServer status and capabilities
Server status and capabilities
No parameter schema in public metadata yet.
load_projectLoad Maven/Gradle/Bazel/plain Java project
Load Maven/Gradle/Bazel/plain Java project
No parameter schema in public metadata yet.
get_project_structureGet package hierarchy
Get package hierarchy
No parameter schema in public metadata yet.
get_classpath_infoGet classpath entries
Get classpath entries
No parameter schema in public metadata yet.
get_type_membersGet members by type name
Get members by type name
No parameter schema in public metadata yet.
get_super_methodFind overridden method in superclass
Find overridden method in superclass
No parameter schema in public metadata yet.
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JAVA_PROJECT_PATHAuto-load project on startup
JAVALENS_TIMEOUT_SECONDSTime limit on each tool call in seconds (5-300); unset means no limit
JAVALENS_LOG_LEVELdefault: INFOLog level: TRACE, DEBUG, INFO, WARN, ERROR
Readme
JavaLens: AI-First Code Analysis for Java
An MCP server providing 75 semantic analysis tools for Java, built directly on Eclipse JDT for compiler-accurate code understanding.
Built for AI Agents
JavaLens exists because AI systems need compiler-accurate insights that reading source files cannot provide. When an AI uses grep or Read to find usages of a method, it cannot distinguish:
- A method call from a method with the same name in an unrelated class
- A field read from a field write
- An interface implementation from an unrelated class
- A cast to a type from other references to that type
This leads to incorrect refactorings, missed usages, and incomplete understanding of code behavior.
Compiler-Accurate Analysis
Details
- Repository
- github.com/pzalutski-pixel/javalens-mcp
- Package
javalens-mcp- Transport
- STDIO
- Registry
- MCP registry, active