Made changes to upgrade the module spring-resttemplate-3 to Spring Boot 3. (#15455)

Author: amit2103

spring-web-modules/spring-resttemplate-3/pom.xml

@@ -10,9 +10,9 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>parent-boot-2</artifactId>
+        <artifactId>parent-boot-3</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../../parent-boot-2</relativePath>
+        <relativePath>../../parent-boot-3</relativePath>
     </parent>
 
     <dependencies>
@@ -24,6 +24,16 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.apache.httpcomponents.client5</groupId>
+            <artifactId>httpclient5</artifactId>
+            <version>${httpclient5.version}</version>
+        </dependency>
     </dependencies>
 
+    <properties>
+        <start-class>com.baeldung.resttemplate.methods.RestTemplateMethodsApplication</start-class>
+        <httpclient5.version>5.2.1</httpclient5.version>
+    </properties>
+
 </project>

spring-web-modules/spring-resttemplate-3/src/main/java/com/baeldung/resttemplate/custom/CustomRestTemplateConfiguration.java

@@ -9,10 +9,12 @@
 
 import javax.net.ssl.SSLContext;
 
-import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
-import org.apache.http.impl.client.CloseableHttpClient;
-import org.apache.http.impl.client.HttpClients;
-import org.apache.http.ssl.SSLContextBuilder;
+import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
+import org.apache.hc.client5.http.impl.classic.HttpClients;
+import org.apache.hc.client5.http.impl.io.PoolingHttpClientConnectionManagerBuilder;
+import org.apache.hc.client5.http.io.HttpClientConnectionManager;
+import org.apache.hc.client5.http.ssl.SSLConnectionSocketFactory;
+import org.apache.hc.core5.ssl.SSLContextBuilder;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -38,7 +40,11 @@ public RestTemplate restTemplate() throws KeyManagementException, NoSuchAlgorith
          .loadTrustMaterial(trustStore.getURL(), trustStorePassword.toCharArray()).build();
         SSLConnectionSocketFactory sslConFactory = new SSLConnectionSocketFactory(sslContext);
 
-        CloseableHttpClient httpClient = HttpClients.custom().setSSLSocketFactory(sslConFactory).build();
+        final HttpClientConnectionManager cm = PoolingHttpClientConnectionManagerBuilder.create()
+                .setSSLSocketFactory(sslConFactory)
+                .build();
+
+        CloseableHttpClient httpClient = HttpClients.custom().setConnectionManager(cm).build();
         ClientHttpRequestFactory requestFactory = new HttpComponentsClientHttpRequestFactory(httpClient);
         return new RestTemplate(requestFactory);
     }