10_Аспекты

build.gradle.kts

@@ -19,8 +19,12 @@ repositories {
 
 dependencies {
 	implementation("org.springframework.boot:spring-boot-starter")
+	implementation("org.springframework.boot:spring-boot-starter-web")
+	implementation("org.springframework.boot:spring-boot-starter-aop")
+	compileOnly("org.projectlombok:lombok")
 	testImplementation("org.springframework.boot:spring-boot-starter-test")
 	testRuntimeOnly("org.junit.platform:junit-platform-launcher")
+	annotationProcessor("org.projectlombok:lombok")
 }
 
 tasks.withType<Test> {

src/main/java/org/javaspringcourse/Exception/ErrorResponse.java

@@ -0,0 +1,4 @@
+package org.javaspringcourse.Exception;
+
+public record ErrorResponse(String message) {
+}

src/main/java/org/javaspringcourse/Exception/TooManyRequestsException.java

@@ -0,0 +1,7 @@
+package org.javaspringcourse.Exception;
+
+public class TooManyRequestsException extends RuntimeException {
+    public TooManyRequestsException(String message) {
+        super(message);
+    }
+}

src/main/java/org/javaspringcourse/Exception/TooManyRequestsExceptionHandler.java

@@ -0,0 +1,16 @@
+package org.javaspringcourse.Exception;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+
+@RestControllerAdvice
+public class TooManyRequestsExceptionHandler {
+
+    @ResponseStatus(HttpStatus.TOO_MANY_REQUESTS)
+    @ExceptionHandler(TooManyRequestsException.class)
+    public ErrorResponse handle(TooManyRequestsException e) {
+        return new ErrorResponse(e.getMessage());
+    }
+}

src/main/java/org/javaspringcourse/RequestsLimit/RequestsLimit.java

@@ -0,0 +1,11 @@
+package org.javaspringcourse.RequestsLimit;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.METHOD)
+public @interface RequestsLimit {
+}

src/main/java/org/javaspringcourse/RequestsLimit/RequestsLimitAspect.java

@@ -0,0 +1,23 @@
+package org.javaspringcourse.RequestsLimit;
+
+import lombok.RequiredArgsConstructor;
+import org.aspectj.lang.JoinPoint;
+import org.aspectj.lang.annotation.Aspect;
+import org.aspectj.lang.annotation.Before;
+import org.javaspringcourse.Exception.TooManyRequestsException;
+import org.springframework.stereotype.Component;
+
+@Component
+@Aspect
+@RequiredArgsConstructor
+public class RequestsLimitAspect {
+    private final RequestsLimitService requestsLimitService;
+
+    @Before(value = "@annotation(RequestsLimit)")
+    private void before(JoinPoint joinPoint) {
+        if (!requestsLimitService.canHandleRequest(
+                joinPoint.getSignature().getName())) {
+            throw new TooManyRequestsException("Too many requests.");
+        }
+    }
+}

src/main/java/org/javaspringcourse/RequestsLimit/RequestsLimitService.java

@@ -0,0 +1,24 @@
+package org.javaspringcourse.RequestsLimit;
+
+import lombok.RequiredArgsConstructor;
+import org.javaspringcourse.props.RequestsLimitProps;
+import org.springframework.stereotype.Service;
+
+import java.util.HashMap;
+import java.util.Map;
+
+@Service
+@RequiredArgsConstructor
+public class RequestsLimitService {
+    private final RequestsLimitProps requestsLimitProps;
+    private final Map<String, Integer> requestsCount = new HashMap<>();
+
+    public boolean canHandleRequest(String apiName) {
+        if (requestsCount.containsKey(apiName)) {
+            requestsCount.put(apiName, requestsCount.get(apiName) + 1);
+        } else {
+            requestsCount.put(apiName, 1);
+        }
+        return requestsCount.get(apiName) <= requestsLimitProps.getMax();
+    }
+}

src/main/java/org/javaspringcourse/config/AspectConfig.java

@@ -0,0 +1,9 @@
+package org.javaspringcourse.config;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.EnableAspectJAutoProxy;
+
+@Configuration
+@EnableAspectJAutoProxy
+public class AspectConfig {
+}

src/main/java/org/javaspringcourse/controller/ApiController.java

@@ -0,0 +1,23 @@
+package org.javaspringcourse.controller;
+
+import org.javaspringcourse.RequestsLimit.RequestsLimit;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping("/api")
+public class ApiController {
+
+    @RequestsLimit
+    @GetMapping("/getHelloWorld")
+    public String getHelloWorld() {
+        return "Hello World";
+    }
+
+    @RequestsLimit
+    @GetMapping("/getByeWorld")
+    public String getByeWorld() {
+        return "Bye World";
+    }
+}

src/main/java/org/javaspringcourse/props/RequestsLimitProps.java

@@ -0,0 +1,14 @@
+package org.javaspringcourse.props;
+
+import lombok.Getter;
+import lombok.Setter;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.stereotype.Component;
+
+@Getter
+@Setter
+@Component
+@ConfigurationProperties(prefix = "requests-limit")
+public class RequestsLimitProps {
+    private int max;
+}

src/main/resources/application.yaml

@@ -0,0 +1,5 @@
+server:
+  port: 8080
+
+requests-limit:
+  max: 2