Merge pull request #11071 from swagger-api/fix-oom

Author: frantuma

modules/swagger-codegen/pom.xml

@@ -249,6 +249,19 @@
             <artifactId>commons-cli</artifactId>
             <version>${commons-cli-version}</version>
         </dependency>
+        <!--
+            used to pretty print examples generated by ExampleGenerator.
+            an issue with Jackson pretty printing for large specs, where
+            for some reason memory usage goes up to OOM errors.
+            TODO if bug (?) is fixed in Jackson pretty printing, remove
+            the dep and use jackson instead
+         -->
+        <dependency>
+            <groupId>org.json</groupId>
+            <artifactId>json</artifactId>
+            <version>20210307</version>
+        </dependency>
+
         <dependency>
             <groupId>org.testng</groupId>
             <artifactId>testng</artifactId>

modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultCodegen.java

@@ -1381,7 +1381,13 @@ public CodegenModel fromModel(String name, Model model, Map<String, Model> allDe
         m.classname = toModelName(name);
         m.classVarName = toVarName(name);
         m.classFilename = toModelFilename(name);
-        m.modelJson = Json.pretty(model);
+        // NOTE: not using Json.pretty() to write out model, as it
+        // can raise memory consumption (see comment in ExampleGenerator)
+        try {
+            m.modelJson = Json.mapper().writeValueAsString(model);
+        } catch (Exception e) {
+            m.modelJson = "{}";
+        }
         m.externalDocs = model.getExternalDocs();
         m.vendorExtensions = model.getVendorExtensions();
         m.isAlias = typeAliases.containsKey(name);

modules/swagger-codegen/src/main/java/io/swagger/codegen/examples/ExampleGenerator.java

@@ -4,6 +4,7 @@
 import io.swagger.models.ModelImpl;
 import io.swagger.models.properties.*;
 import io.swagger.util.Json;
+import org.json.JSONObject;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -46,7 +47,15 @@ public List<Map<String, String>> generate(Map<String, Object> examples, List<Str
                 Map<String, String> kv = new HashMap<>();
                 kv.put(CONTENT_TYPE, mediaType);
                 if (property != null && mediaType.startsWith(MIME_TYPE_JSON)) {
-                    String example = Json.pretty(resolvePropertyToExample("", mediaType, property, processedModels));
+                    /*
+                        org.json is used to pretty print example, because of an issue with
+                        Jackson pretty printing for large specs, where for some reason
+                        memory usage goes up to OOM errors.
+                        TODO if bug (?) is fixed in Jackson pretty printing, remove the dep and use jackson instead
+                     */
+                    //String example = Json.pretty(resolvePropertyToExample("", mediaType, property, processedModels));
+                    String example = new JSONObject(resolvePropertyToExample("", mediaType, property, processedModels)).toString(2);
+
 
                     if (example != null) {
                         kv.put(EXAMPLE, example);
@@ -91,7 +100,14 @@ public List<Map<String, String>> generate(Map<String, Object> examples, List<Str
                     final Model model = this.examples.get(modelName);
                     if (model != null) {
 
-                        String example = Json.pretty(resolveModelToExample(modelName, mediaType, model, processedModels));
+                        /*
+                            org.json is used to pretty print example, because of an issue with
+                            Jackson pretty printing for large specs, where for some reason
+                            memory usage goes up to OOM errors.
+                            TODO if bug (?) is fixed in Jackson pretty printing, remove the dep and use jackson instead
+                         */
+                        // String example = Json.pretty(resolveModelToExample(modelName, mediaType, model, processedModels));
+                        String example = new JSONObject(resolveModelToExample(modelName, mediaType, model, processedModels)).toString(2);
 
                         if (example != null) {
                             kv.put(EXAMPLE, example);
@@ -216,7 +232,7 @@ private Object resolvePropertyToExample(String propertyName, String mediaType, P
             }
             logger.warn("Ref property with empty model.");
         } else if (property instanceof UUIDProperty) {
-            return "046b6c7f-0b8a-43b9-b35d-6489e6daee91"; 
+            return "046b6c7f-0b8a-43b9-b35d-6489e6daee91";
         }
 
         return "";