Java Source Metrics & API Scanner

A tiny, single-jar CLI that scans a Java source tree and reports:

• Counts: methods, classes, interfaces, enums, LOC
• Spring roles: @RestController/@Controller, @Service, @Repository
• JPA @Entity classes
• “Domain” classes (by package hints: .domain / .model)
• HTTP endpoints from Spring MVC (@GetMapping, @PostMapping, @RequestMapping …) and JAX-RS (@Path, @GET …)

Built on JavaParser. The shaded JAR includes all dependencies—no classpath hassles.

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Requirements

• Java 17+
• Maven 3.8+ (only if you build from source)

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Build

mvn clean package -DskipTests

This produces a fat jar at:

target/my-java-parser.jar

The filename is stable (set via <finalName> in the POM).

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Run

java -jar target/my-java-parser.jar /path/to/java/src/root

Examples:

# macOS/Linux
java -jar target/my-java-parser.jar ~/projects/petclinic/src/main/java

# Windows (PowerShell)
java -jar target\my-java-parser.jar C:\code\myapp\src\main\java

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Output

First, a CSV-style summary:

methods,1234
classes,210
interfaces,18
enums,7
loc,54321
controllers,6
services,14
repositories,5
entities,12
domainClasses,28
endpoints,42

Then detailed lists:

Controllers:
com.example.user.UserController
...

Services:
com.example.user.UserService
...

Entities (@Entity):
com.example.user.User
...

Domain classes (by package name hint):
com.example.model.Address
...

Finally, discovered endpoints:

API Endpoints (method path -> Class#method):
GET    /users               -> com.example.user.UserController#list
POST   /users               -> com.example.user.UserController#create
GET    /api/v1/orders/{id}  -> com.example.order.OrderResource#get
...

Notes

• Spring: supports @GetMapping/@PostMapping/@PutMapping/@DeleteMapping/@PatchMapping and @RequestMapping with path/value (arrays allowed) and method=RequestMethod.*.
• JAX-RS: supports class/method @Path and HTTP verb annotations (@GET, @POST, @PUT, @DELETE, @PATCH, @OPTIONS, @HEAD).
• “Domain” classes are inferred via package hints: .domain or .model.

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Using From a Notebook

A ready-to-use Python notebook (call_javaparser.ipynb) is included in the repo and shows how to invoke the jar programmatically.

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Troubleshooting

• Unable to access jarfile …
  Ensure you’re pointing to target/my-java-parser.jar (not original-*.jar).

• Could not find or load main class …
  Always run with -jar (the manifest already sets Main-Class).

• IDE flags syntax but Maven builds
  Set the project JDK/Language level to 17 and re-import Maven.

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Dev Notes

• Main class: com.example.JavaParserMetrics
• Java: 17 (uses modern features like switch expressions)
• Packaging: shaded (fat) jar via maven-shade-plugin

Quick rebuild:

mvn -q clean package -DskipTests && java -jar target/my-java-parser.jar /path/to/src

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