Rule for RestTemplate Apache HttpClient 5 requirement

default/generated/spring-framework/spring-framework-5.x-to-6.0-web-applications.yaml

@@ -49,3 +49,35 @@
     url: https://github.com/spring-projects/spring-framework/wiki/Spring-Framework-6.0-Release-Notes#web-applications
   - title: 'Specific Spring Framwork change'
     url: https://github.com/spring-projects/spring-framework/issues/28552
+
+- ruleID: spring-framework-5.x-to-6.0-web-applications-00020
+  category: mandatory
+  effort: 5
+  labels:
+  - konveyor.io/source=spring5
+  - konveyor.io/target=spring6+
+  when:
+    and:
+    - java.referenced:
+        pattern: org.springframework.http.client.HttpComponentsClientHttpRequestFactory
+    - java.dependency:
+        name: org.apache.httpcomponents.httpclient
+        upperbound: 4.5.999999
+      ignore: true
+  description: RestTemplate now requires Apache HttpClient 5
+  message: |
+    `RestTemplate`, or rather the `HttpComponentsClientHttpRequestFactory`, now requires Apache HttpClient 5.
+    Please upgrade your HttpClient dependency, ideally to the latest version:
+
+    ```xml
+    <dependency>
+        <groupId>org.apache.httpcomponents.client5</groupId>
+        <artifactId>httpclient5</artifactId>
+        <version>5.4.1</version>
+    </dependency>
+    ```
+  links:
+    - title: 'Spring 6.0 migration guide'
+      url: https://github.com/spring-projects/spring-framework/wiki/Spring-Framework-6.0-Release-Notes#web-applications
+    - title: 'Apache HttpClient 4 to 5 migration guide'
+      url: https://hc.apache.org/httpcomponents-client-5.4.x/migration-guide/preparation.html

default/generated/spring-framework/tests/data/web-applications/pom.xml

@@ -55,6 +55,13 @@
             <version>1.7.36</version>
             <scope>runtime</scope>
         </dependency>
+
+        <!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient -->
+        <dependency>
+            <groupId>org.apache.httpcomponents</groupId>
+            <artifactId>httpclient</artifactId>
+            <version>4.5.4</version>
+        </dependency>
     </dependencies>
 
     <build>

default/generated/spring-framework/tests/data/web-applications/src/main/java/org/konveyor/Main.java

@@ -1,11 +1,17 @@
 package org.konveyor;
 
-import java.beans.IntrospectionException;
+import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
+import org.springframework.web.client.RestTemplate;
+
+import java.net.URI;
 
 public class Main {
 
-    public static void main(String[] args) throws IntrospectionException {
+    public static void main(String[] args) {
+        RestTemplate rest = new RestTemplate();
+        rest.getForEntity(URI.create("http://www.example.com/"), Object.class);
 
+        HttpComponentsClientHttpRequestFactory factory = new HttpComponentsClientHttpRequestFactory();
     }
 
 }

default/generated/spring-framework/tests/spring-framework-5.x-to-6.0-web-applications.test.yaml

@@ -10,3 +10,10 @@ tests:
       mode: "source-only"
     hasIncidents:
       exactly: 1
+- ruleID: spring-framework-5.x-to-6.0-web-applications-00020
+  testCases:
+    - name: tc-1
+      analysisParams:
+        mode: "source-only"
+      hasIncidents:
+        exactly: 2