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| package com.example.demo.product;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PatchMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.math.BigDecimal;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.atomic.AtomicLong;
@RestController
@RequestMapping("/api/v1/products")
public class ProductController {
private final List<Product> store = new CopyOnWriteArrayList<>();
private final AtomicLong idGen = new AtomicLong(0);
public record Product(Long id, String description, BigDecimal price, int stock) {}
public record CreateProductRequest(String description, BigDecimal price, Integer stock) {}
public record PatchProductRequest(String description, BigDecimal price, Integer stock) {}
public ProductController() {
store.add(new Product(idGen.incrementAndGet(), "Demo A", new BigDecimal("99.90"), 10));
store.add(new Product(idGen.incrementAndGet(), "Demo B", new BigDecimal("199.00"), 5));
}
@GetMapping
public List<Product> list() {
return store;
}
@GetMapping("/{id}")
public ResponseEntity<Product> getById(@PathVariable Long id) {
int idx = indexOfId(id);
if (idx < 0) {
return ResponseEntity.status(HttpStatus.NOT_FOUND).build();
}
return ResponseEntity.ok(store.get(idx));
}
@PostMapping
public ResponseEntity<Product> create(@RequestBody CreateProductRequest req) {
if (!isValidCreate(req)) {
return ResponseEntity.status(HttpStatus.BAD_REQUEST).build();
}
long id = idGen.incrementAndGet();
Product product = new Product(id, req.description(), req.price(), req.stock());
store.add(product);
return ResponseEntity
.status(HttpStatus.CREATED)
.header(HttpHeaders.LOCATION, "/api/v1/products/" + id)
.body(product);
}
@PatchMapping("/{id}")
public ResponseEntity<Product> patch(@PathVariable Long id, @RequestBody PatchProductRequest req) {
int idx = indexOfId(id);
if (idx < 0) {
return ResponseEntity.status(HttpStatus.NOT_FOUND).build();
}
Product old = store.get(idx);
String newDescription = req != null && req.description() != null ? req.description() : old.description();
BigDecimal newPrice = req != null && req.price() != null ? req.price() : old.price();
Integer newStockBoxed = req != null && req.stock() != null ? req.stock() : old.stock();
if (!isValidFields(newDescription, newPrice, newStockBoxed)) {
return ResponseEntity.status(HttpStatus.BAD_REQUEST).build();
}
Product updated = new Product(id, newDescription, newPrice, newStockBoxed);
store.set(idx, updated);
return ResponseEntity.ok(updated);
}
@DeleteMapping("/{id}")
public ResponseEntity<Void> delete(@PathVariable Long id) {
boolean removed = store.removeIf(p -> p.id().equals(id));
return removed ? ResponseEntity.noContent().build() : ResponseEntity.status(HttpStatus.NOT_FOUND).build();
}
private int indexOfId(Long id) {
for (int i = 0; i < store.size(); i++) {
if (store.get(i).id().equals(id)) {
return i;
}
}
return -1;
}
private boolean isValidCreate(CreateProductRequest req) {
if (req == null || req.description() == null || req.description().isBlank()) return false;
if (req.price() == null || req.price().compareTo(BigDecimal.ZERO) < 0) return false;
if (req.stock() == null || req.stock() < 0) return false;
return true;
}
private boolean isValidFields(String description, BigDecimal price, Integer stock) {
if (description == null || description.isBlank()) return false;
if (price == null || price.compareTo(BigDecimal.ZERO) < 0) return false;
if (stock == null || stock < 0) return false;
return true;
}
}
|
