Spring Boot - 🧪 Mini Project: String Intelligence Engine for Retail Products

[akash-coded]

🧪 Mini Project: String Intelligence Engine for Retail Products

🏪 Context:

You’ve just joined a retail e-commerce startup. Your task is to build a microservice that powers search relevance and tag processing for product names, descriptions, and customer queries using string operations — all exposed via REST endpoints.

The service must:

• Be modular, enterprise-grade
• Include Actuator for monitoring
• Have clearly separated controller → service → model → utility layers
• Run on port 8081
• Follow good practices (naming, JavaDocs, constants, exception handling)

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🎯 Project Objectives:

• ✅ Use advanced String functions and Collections
• ✅ Follow N-tier architecture (Controller → Service → Utility)
• ✅ Apply @RestController, @RequestParam, @Value
• ✅ Enable and expose Actuator endpoints
• ✅ Organize project folders correctly
• ✅ Include detailed output logging
• ✅ Show performance/health via actuator

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📁 Folder Structure (GitHub Markdown)

string-intelligence/
├── src/main/java/com/retail/stringintel/
│   ├── controller/
│   │   └── ProductStringController.java
│   ├── service/
│   │   └── ProductStringService.java
│   ├── util/
│   │   └── StringUtilsPro.java
│   ├── model/
│   │   └── ProductDTO.java
│   ├── StringIntelligenceApplication.java
├── src/main/resources/
│   └── application.properties

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📌 Step-by-Step Exercise

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🧩 STEP 1: Setup Spring Boot Project

Instructions:

• Go to https://start.spring.io/

• Add dependencies:

  • Spring Web
  • Spring Boot DevTools
  • Spring Boot Actuator
  • Lombok

Set project name: string-intelligence

Hint: Use Java 17 or 21.

---

📜 STEP 2: Configure application.properties

# Port
server.port=8081

# Actuator config
management.endpoints.web.exposure.include=*
management.endpoint.health.show-details=always

# App Info
info.app.name=Retail String Intelligence Service
info.app.version=1.0.0
info.app.owner=team@retailgenie.ai

🧠 Pro Tip: Try hitting /actuator/info once app runs.

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🧩 STEP 3: Create ProductDTO.java in model/

package com.retail.stringintel.model;

import lombok.Data;

@Data
public class ProductDTO {
    private String productName;
    private String description;
    private String tags;
}

---

🧩 STEP 4: Implement String Utilities in StringUtilsPro.java

package com.retail.stringintel.util;

public class StringUtilsPro {

    public static String toSlug(String input) {
        return input.toLowerCase().replaceAll("[^a-z0-9]", "-").replaceAll("-{2,}", "-");
    }

    public static int wordCount(String input) {
        return input.trim().split("\\s+").length;
    }

    public static String highlight(String input, String keyword) {
        return input.replaceAll("(?i)(" + keyword + ")", "**$1**");
    }

    public static boolean fuzzyMatch(String input1, String input2) {
        return input1.toLowerCase().contains(input2.toLowerCase());
    }
}

---

🧩 STEP 5: Implement Service Logic in ProductStringService.java

package com.retail.stringintel.service;

import com.retail.stringintel.model.ProductDTO;
import com.retail.stringintel.util.StringUtilsPro;
import org.springframework.stereotype.Service;

@Service
public class ProductStringService {

    public String getSlug(ProductDTO product) {
        return StringUtilsPro.toSlug(product.getProductName());
    }

    public int getDescriptionWordCount(ProductDTO product) {
        return StringUtilsPro.wordCount(product.getDescription());
    }

    public String highlightTag(ProductDTO product, String tag) {
        return StringUtilsPro.highlight(product.getTags(), tag);
    }

    public boolean isSearchMatch(String productTitle, String query) {
        return StringUtilsPro.fuzzyMatch(productTitle, query);
    }
}

---

🧩 STEP 6: Create Controller ProductStringController.java

package com.retail.stringintel.controller;

import com.retail.stringintel.model.ProductDTO;
import com.retail.stringintel.service.ProductStringService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

@RestController
@RequestMapping("/api/stringops")
public class ProductStringController {

    @Autowired
    private ProductStringService stringService;

    @PostMapping("/slug")
    public String createSlug(@RequestBody ProductDTO product) {
        return stringService.getSlug(product);
    }

    @PostMapping("/wordcount")
    public int getWordCount(@RequestBody ProductDTO product) {
        return stringService.getDescriptionWordCount(product);
    }

    @PostMapping("/highlight")
    public String highlightTags(@RequestBody ProductDTO product, @RequestParam String keyword) {
        return stringService.highlightTag(product, keyword);
    }

    @GetMapping("/match")
    public boolean searchMatch(@RequestParam String title, @RequestParam String search) {
        return stringService.isSearchMatch(title, search);
    }
}

---

🔁 Practice Tasks (Student Must Do)

• ❓ Fill-in-the-blank: Add a new /containsAllWords API to check if a title contains all query words
• 🔧 Fix the bug: If /slug returns -- between words, fix the regex
• 💡 Explore: Add a new String utility to clean HTML tags from descriptions
• 🎯 Riddle: What will the API return if title is null? Add null check

---

🧪 Bonus: Postman Testing Ideas

• Test /slug with:

  {
    "productName": "iPhone 15 Pro Max - 128GB"
  }

  ➜ Should return: iphone-15-pro-max-128gb

• Test /highlight?keyword=apple with:

  {
    "tags": "Apple iPhone Premium Smartphone"
  }

• Test /match?title=Sony WH-1000XM5&search=sony ➜ Should return true

---

🚨 Actuator Testing

• Hit:

  • /actuator/health
  • /actuator/info
  • /actuator/metrics/http.server.requests

• Analyze how many times /slug is hit

---

🧠 Concepts Reinforced

• Functional decomposition
• String processing in enterprise use-cases
• @RequestParam + @RequestBody usage
• REST API structuring
• Monitoring with actuator
• Regex, fuzzy matching, and stream-style utilities

[akash-coded]

String_Intelligence_API_Guide.pdf

[akash-coded]

string_intelligence_api_postman_collection.json

[prasetha21-max]

PRASETHA N
string-intelligence.zip