[41] rest template 을 connection pool 로 관리하기

build.gradle

@@ -47,6 +47,9 @@ dependencies {
     runtimeOnly 'com.mysql:mysql-connector-j'
     annotationProcessor 'org.projectlombok:lombok'
     // Project Common Dependency End ----------------------------------------
+    // HttpComponent for restTemplate connection pool
+    implementation 'org.apache.httpcomponents.client5:httpclient5:5.3'
+    implementation 'org.apache.httpcomponents.core5:httpcore5:5.3'
 
     // QueryDsl
     implementation 'com.querydsl:querydsl-jpa:5.0.0:jakarta'

src/main/java/org/example/commerce_site/config/RestTemplateConfig.java

@@ -0,0 +1,71 @@
+package org.example.commerce_site.config;
+
+import static org.springframework.http.HttpStatus.*;
+
+import java.io.IOException;
+import java.util.concurrent.TimeUnit;
+
+import org.apache.hc.client5.http.config.RequestConfig;
+import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
+import org.apache.hc.client5.http.impl.classic.HttpClientBuilder;
+import org.apache.hc.client5.http.impl.io.PoolingHttpClientConnectionManager;
+import org.example.commerce_site.common.exception.CustomException;
+import org.example.commerce_site.common.exception.ErrorCode;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.http.client.ClientHttpResponse;
+import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
+import org.springframework.web.client.ResponseErrorHandler;
+import org.springframework.web.client.RestTemplate;
+
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+@Configuration
+public class RestTemplateConfig {
+	@Bean
+	RestTemplate restTemplate() {
+		PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager();
+		connectionManager.setMaxTotal(100);
+		connectionManager.setDefaultMaxPerRoute(30);
+
+		RequestConfig requestConfig = RequestConfig.custom()
+			.setResponseTimeout(5000, TimeUnit.MILLISECONDS)
+			.build();
+
+		CloseableHttpClient httpClient = HttpClientBuilder.create()
+			.setDefaultRequestConfig(requestConfig)
+			.setConnectionManager(connectionManager)
+			.build();
+
+		HttpComponentsClientHttpRequestFactory factory = new HttpComponentsClientHttpRequestFactory();
+		factory.setConnectTimeout(3000);
+		factory.setHttpClient(httpClient);
+
+		RestTemplate restTemplate = new RestTemplate(factory);
+
+		restTemplate.setErrorHandler(new ResponseErrorHandler() {
+			@Override
+			public boolean hasError(ClientHttpResponse response) throws IOException {
+				return response.getStatusCode().is4xxClientError() || response.getStatusCode().is5xxServerError();
+			}
+
+			@Override
+			public void handleError(ClientHttpResponse response) throws IOException {
+				log.error("Error occurred : {} ", response.getStatusCode());
+				switch (response.getStatusCode()) {
+					case UNAUTHORIZED:
+						throw new CustomException(ErrorCode.UNAUTHORIZED);
+					case FORBIDDEN:
+						throw new CustomException(ErrorCode.ACCESS_DENIED);
+					case NOT_FOUND:
+						throw new CustomException(ErrorCode.NOT_FOUND);
+					default:
+						throw new CustomException(ErrorCode.INTERNAL_SERVER_ERROR);
+				}
+			}
+		});
+
+		return restTemplate;
+	}
+}

src/main/resources/application.yml

@@ -71,5 +71,11 @@ auth:
 logging:
   level:
     org:
+      apache:
+        http: DEBUG
+        tomcat.util.net: DEBUG
       springframework:
-        security: DEBUG
+        security: DEBUG
+    sun:
+      security:
+        ssl: DEBUG