Add postProcess method to show donation message (#8142)

* add postProcess method to show donation message

* update comment

Author: wing328

modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenConfig.java

@@ -182,6 +182,8 @@ public interface CodegenConfig {
 
     Map<String, Object> updateAllModels(Map<String, Object> objs);
 
+    void postProcess();
+
     Map<String, Object> postProcessAllModels(Map<String, Object> objs);
 
     Map<String, Object> postProcessModels(Map<String, Object> objs);

modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java

@@ -747,6 +747,16 @@ public void setOpenAPI(OpenAPI openAPI) {
         ModelUtils.setDisallowAdditionalPropertiesIfNotPresent(getDisallowAdditionalPropertiesIfNotPresent());
     }
 
+    // override with any message to be shown right before the process finishes
+    @SuppressWarnings("static-method")
+    public void postProcess() {
+        System.out.println("################################################################################");
+        System.out.println("# Thanks for using OpenAPI Generator.                                          #");
+        System.out.println("# Please consider donation to help us maintain this project \uD83D\uDE4F                 #");
+        System.out.println("# https://opencollective.com/openapi_generator/donate                          #");
+        System.out.println("################################################################################");
+    }
+
     // override with any special post-processing
     @SuppressWarnings("static-method")
     public Map<String, Object> postProcessOperationsWithModels(Map<String, Object> objs, List<Object> allModels) {

modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultGenerator.java

@@ -925,6 +925,9 @@ public List<File> generate() {
             }
         }
 
+        // post-process
+        config.postProcess();
+
         // reset GlobalSettings, so that the running thread can be reused for another generator-run
         GlobalSettings.reset();