diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
index d3998a47bca..507a4d1d59f 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
@@ -810,7 +810,7 @@ public class DefaultCodegen implements CodegenConfig {
      * @return the snake-cased variable name
      */
     public String toApiVarName(String name) {
-        return snakeCase(name);
+        return lowerCamelCase(name);
     }
 
     /**
@@ -1533,13 +1533,13 @@ public class DefaultCodegen implements CodegenConfig {
     }
 
     /**
-     * Return the snake-case of the string
+     * Return the lowerCamelCase of the string
      *
-     * @param name string to be snake-cased
-     * @return snake-cased string
+     * @param name string to be lowerCamelCased
+     * @return lowerCamelCase string
      */
     @SuppressWarnings("static-method")
-    public String snakeCase(String name) {
+    public String lowerCamelCase(String name) {
         return (name.length() > 0) ? (Character.toLowerCase(name.charAt(0)) + name.substring(1)) : "";
     }
 
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ErlangClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ErlangClientCodegen.java
index 8d5836f717f..f924229a172 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ErlangClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ErlangClientCodegen.java
@@ -128,7 +128,7 @@ public class ErlangClientCodegen extends DefaultCodegen implements CodegenConfig
             if (languageSpecificPrimitives.contains(type))
                 return (type);
         } else
-            type = getTypeDeclaration(toModelName(snakeCase(schemaType)));
+            type = getTypeDeclaration(toModelName(lowerCamelCase(schemaType)));
         return type;
     }
 
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ErlangProperCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ErlangProperCodegen.java
index 5d935d75bdc..011501670b7 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ErlangProperCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ErlangProperCodegen.java
@@ -137,7 +137,7 @@ public class ErlangProperCodegen extends DefaultCodegen implements CodegenConfig
         } else if (typeMapping.containsKey(typeDeclaration)) {
             return typeMapping.get(typeDeclaration);
         } else {
-            return getTypeDeclaration(toModelName(snakeCase(typeDeclaration)));
+            return getTypeDeclaration(toModelName(lowerCamelCase(typeDeclaration)));
         }
     }
 
@@ -179,7 +179,7 @@ public class ErlangProperCodegen extends DefaultCodegen implements CodegenConfig
         } else if (typeMapping.containsKey(schemaType)) {
             return typeMapping.get(schemaType);
         } else {
-            return getTypeDeclaration(toModelName(snakeCase(schemaType)));
+            return getTypeDeclaration(toModelName(lowerCamelCase(schemaType)));
         }
     }
 
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaClientCodegen.java
index b95c9bf8d3b..89ad9e0dd91 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaClientCodegen.java
@@ -695,4 +695,12 @@ public class JavaClientCodegen extends AbstractJavaCodegen
         return mime != null && JSON_VENDOR_MIME_PATTERN.matcher(mime).matches();
     }
 
+    @Override
+    public String toApiVarName(String name) {
+        String apiVarName = super.toApiVarName(name);
+        if (reservedWords.contains(apiVarName)) {
+            apiVarName = escapeReservedWord(apiVarName);
+        }
+        return apiVarName;
+    }
 }
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PhpSymfonyServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PhpSymfonyServerCodegen.java
index d29dd788497..4a58052af4b 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PhpSymfonyServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PhpSymfonyServerCodegen.java
@@ -200,7 +200,7 @@ public class PhpSymfonyServerCodegen extends AbstractPhpCodegen implements Codeg
         if (alias != null && !alias.isEmpty()) {
             this.bundleAlias = alias.toLowerCase(Locale.ROOT);
         } else {
-            this.bundleAlias = snakeCase(bundleName).replaceAll("([A-Z]+)", "\\_$1").toLowerCase(Locale.ROOT);
+            this.bundleAlias = lowerCamelCase(bundleName).replaceAll("([A-Z]+)", "\\_$1").toLowerCase(Locale.ROOT);
         }
     }
 
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java
index acfd791fd03..48183b49efb 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java
@@ -68,7 +68,7 @@ import java.util.stream.Collectors;
 public class JavaClientCodegenTest {
 
     @Test
-    public void arraysInRequestBody() throws Exception {
+    public void arraysInRequestBody() {
         OpenAPI openAPI = TestUtils.createOpenAPI();
         final JavaClientCodegen codegen = new JavaClientCodegen();
         codegen.setOpenAPI(openAPI);
@@ -103,8 +103,7 @@ public class JavaClientCodegenTest {
     }
 
     @Test
-    public void nullValuesInComposedSchema() throws Exception {
-        OpenAPI openAPI = TestUtils.createOpenAPI();
+    public void nullValuesInComposedSchema() {
         final JavaClientCodegen codegen = new JavaClientCodegen();
         ComposedSchema schema = new ComposedSchema();
         CodegenModel result = codegen.fromModel("CompSche",
@@ -192,7 +191,7 @@ public class JavaClientCodegenTest {
     }
 
     @Test
-    public void testPackageNamesSetInvokerDerivedFromApi() throws Exception {
+    public void testPackageNamesSetInvokerDerivedFromApi() {
         final JavaClientCodegen codegen = new JavaClientCodegen();
         codegen.additionalProperties().put(CodegenConstants.MODEL_PACKAGE, "xyz.yyyyy.zzzzzzz.mmmmm.model");
         codegen.additionalProperties().put(CodegenConstants.API_PACKAGE, "xyz.yyyyy.zzzzzzz.aaaaa.api");
@@ -207,7 +206,7 @@ public class JavaClientCodegenTest {
     }
 
     @Test
-    public void testPackageNamesSetInvokerDerivedFromModel() throws Exception {
+    public void testPackageNamesSetInvokerDerivedFromModel() {
         final JavaClientCodegen codegen = new JavaClientCodegen();
         codegen.additionalProperties().put(CodegenConstants.MODEL_PACKAGE, "xyz.yyyyy.zzzzzzz.mmmmm.model");
         codegen.processOpts();
@@ -455,4 +454,12 @@ public class JavaClientCodegenTest {
         codegenParameter.dataType = "String";
         return codegenParameter;
     }
+
+    @Test
+    public void escapeName() {
+        final JavaClientCodegen codegen = new JavaClientCodegen();
+        assertEquals("_default", codegen.toApiVarName("Default"));
+        assertEquals("_int", codegen.toApiVarName("int"));
+        assertEquals("pony", codegen.toApiVarName("pony"));
+    }
 }