feat: 로그인 기능 추가

backend/src/main/java/com/funeat/auth/dto/LoginRequest.java

@@ -0,0 +1,14 @@
+package com.funeat.auth.dto;
+
+public class LoginRequest {
+
+    private final Long id;
+
+    public LoginRequest(final Long id) {
+        this.id = id;
+    }
+
+    public Long getId() {
+        return id;
+    }
+}

backend/src/main/java/com/funeat/auth/util/AuthArgumentResolver.java

@@ -0,0 +1,36 @@
+package com.funeat.auth.util;
+
+import com.funeat.auth.dto.LoginRequest;
+import java.util.Objects;
+import javax.servlet.http.HttpServletRequest;
+import org.springframework.core.MethodParameter;
+import org.springframework.stereotype.Component;
+import org.springframework.web.bind.support.WebDataBinderFactory;
+import org.springframework.web.context.request.NativeWebRequest;
+import org.springframework.web.method.support.HandlerMethodArgumentResolver;
+import org.springframework.web.method.support.ModelAndViewContainer;
+
+@Component
+public class AuthArgumentResolver implements HandlerMethodArgumentResolver {
+
+    private final JwtTokenProvider jwtTokenProvider;
+
+    public AuthArgumentResolver(final JwtTokenProvider jwtTokenProvider) {
+        this.jwtTokenProvider = jwtTokenProvider;
+    }
+
+    @Override
+    public boolean supportsParameter(MethodParameter parameter) {
+        return parameter.hasParameterAnnotation(AuthenticationPrincipal.class);
+    }
+
+    @Override
+    public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer,
+                                  NativeWebRequest webRequest, WebDataBinderFactory binderFactory) {
+        final HttpServletRequest request = webRequest.getNativeRequest(HttpServletRequest.class);
+        final String token = AuthorizationExtractor.extract(Objects.requireNonNull(request));
+        final String id = jwtTokenProvider.getPayload(token);
+
+        return new LoginRequest(Long.valueOf(id));
+    }
+}

backend/src/main/java/com/funeat/auth/util/AuthenticationPrincipal.java

@@ -0,0 +1,11 @@
+package com.funeat.auth.util;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target(ElementType.PARAMETER)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface AuthenticationPrincipal {
+}

backend/src/main/java/com/funeat/common/WebConfig.java

@@ -1,14 +1,28 @@
 package com.funeat.common;
 
+import com.funeat.auth.util.AuthArgumentResolver;
+import java.util.List;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.format.FormatterRegistry;
+import org.springframework.web.method.support.HandlerMethodArgumentResolver;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
 
 @Configuration
 public class WebConfig implements WebMvcConfigurer {
 
+    private final AuthArgumentResolver authArgumentResolver;
+
+    public WebConfig(AuthArgumentResolver authArgumentResolver) {
+        this.authArgumentResolver = authArgumentResolver;
+    }
+
     @Override
     public void addFormatters(final FormatterRegistry registry) {
         registry.addConverter(new StringToCategoryTypeConverter());
     }
+
+    @Override
+    public void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) {
+        resolvers.add(authArgumentResolver);
+    }
 }