Реализовал api для UserDTO

nekontakte/src/main/java/com/example/nekontakte/NekontakteApplication.java

@@ -2,10 +2,11 @@ package com.example.nekontakte;
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.web.bind.annotation.RestController;
 
 @SpringBootApplication
+@RestController
 public class NekontakteApplication {
-
 	public static void main(String[] args) {
 		SpringApplication.run(NekontakteApplication.class, args);
 	}

nekontakte/src/main/java/com/example/nekontakte/UserApiEndpoint.java

@@ -0,0 +1,64 @@
+package com.example.nekontakte;
+
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.server.ResponseStatusException;
+
+import java.util.HashMap;
+import java.util.List;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+
+@RestController
+@RequestMapping("/user")
+public class UserApiEndpoint {
+    private Integer lastUserId = 0;
+    private HashMap<Integer, UserDTO> users = new HashMap<>();
+
+    @GetMapping()
+    public List<UserDTO> getUsers() {
+        return users.values().stream().toList();
+    }
+
+    @GetMapping("/{id}")
+    public UserDTO getUser(@PathVariable Integer id) {
+        if (users.containsKey(id)) {
+            return users.get(id);
+        }
+        throw new ResponseStatusException(HttpStatus.NOT_FOUND);
+    }
+
+    @PostMapping()
+    public UserDTO postUser(@RequestBody UserDTO entity) {
+        Integer currentUserId = lastUserId + 1;
+        entity.setId(currentUserId);
+        users.put(currentUserId, entity);
+        lastUserId++;
+        return entity;
+    }
+
+    @PutMapping("/{id}")
+    public UserDTO putUser(@PathVariable Integer id, @RequestBody UserDTO entity) {
+        if (users.containsKey(id)) {
+            entity.setId(id);
+            users.put(id, entity);
+            return entity;
+        }
+        throw new ResponseStatusException(HttpStatus.NOT_FOUND);
+    }
+
+    @DeleteMapping("/{id}")
+    public UserDTO deleteUser(@PathVariable Integer id) {
+        if (users.containsKey(id)) {
+            return users.remove(id);
+        }
+        throw new ResponseStatusException(HttpStatus.NOT_FOUND);
+    }
+
+}

nekontakte/src/main/java/com/example/nekontakte/WebConfig.java

@@ -2,7 +2,10 @@ package com.example.nekontakte;
 
 import org.springframework.context.annotation.Configuration;
 import org.springframework.lang.NonNull;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.method.HandlerTypePredicate;
 import org.springframework.web.servlet.config.annotation.CorsRegistry;
+import org.springframework.web.servlet.config.annotation.PathMatchConfigurer;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
 
 @Configuration
@@ -13,4 +16,9 @@ public class WebConfig implements WebMvcConfigurer {
                 .allowedMethods("GET", "POST", "PUT", "DELETE");
 
     }
+
+    @Override
+    public void configurePathMatch(@SuppressWarnings("null") PathMatchConfigurer configurer) {
+        configurer.addPathPrefix("api", HandlerTypePredicate.forAnnotation(RestController.class));
+    }
 }