codelens-source-lookup

name	codelens-source-lookup
description	| Use when this capability is needed.

Source Lookup

This skill enables viewing source code for any JVM class accessible to the project.

When to Use

• View the implementation of a class or method
• Read javadoc documentation for a library class
• Generate interface stubs for understanding API contracts
• Inspect JDK source code
• View decompiled bytecode when source is unavailable

Prerequisites

Ensure the CodeLens server is running for your project:

codelens start --project /path/to/project

To look up project class source, the project must be compiled — CodeLens discovers project classes by scanning compiled bytecode (build/classes), so build it first (./gradlew build -x test). Library and JDK source lookups work regardless. If project classes aren't found, check codelens classes stats --json (a projectClassCount of 0, also flagged by a warning: from start, means rebuild then codelens refresh).

Output: in a terminal these commands print the source code directly. Pass --json for the structured envelope documented in FORMATS.md (source.content, filePath, language, …) — that JSON shape is also auto-selected when output is piped or captured.

Commands

View Full Source

codelens source show <fully-qualified-class-name>

Examples:

# Project class
codelens source show com.example.MyHandler

# Library class (auto-downloads source JAR if available)
codelens source show com.google.common.collect.ImmutableList

# JDK class
codelens source show java.util.concurrent.CompletableFuture

View Method Source

Extract a specific method from a class:

codelens source method <class-fqn> <method-name>

Options:

• --param-types <types> - Disambiguate overloaded methods (comma-separated parameter types)
• --context <n> - Include n lines before/after the method

Examples:

# Simple method
codelens source method com.example.UserService getUser

# Overloaded method - specify parameter types
codelens source method com.example.UserService findUsers --param-types "String,int"

# With surrounding context
codelens source method com.example.MyHandler handle --context 5

Output Today

codelens source show <fqn> returns the full resolved source for the class (default behavior). Richer output modes — stub generation, signatures-only, javadoc extraction, visibility filtering, and Java/Kotlin language switching — exist on the server endpoint but are not yet exposed on the CLI. They are queued as a follow-up Go-CLI enhancement; once landed, this section will be expanded with --format, --visibility, and --lang examples.

Source Resolution

CodeLens resolves source in this order:

1. Project source - Your local source files
2. Library source JARs - Downloaded from Maven Central
3. JDK source - From src.zip or JDK modules
4. Decompilation - Fallback when source unavailable

The server endpoint accepts query parameters to disable decompilation fallback or force a fresh source-JAR download, but those toggles are not yet exposed on the CLI. They are queued alongside the format/visibility flags in the follow-up Go-CLI enhancement noted above.

Tips

• Combine with codelens-jvm-analysis skill to find classes first, then view their source
• When viewing library code, source JARs are cached locally after first download
• Decompiled code may not perfectly match original source but preserves logic

Related Skills

• codelens-jvm-analysis - Find classes and methods to view
• codelens-ratpack-analysis - Analyze Ratpack-specific handler source

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Source: charliek/codelens — distributed by TomeVault.