diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/auth/HttpBasicAuth.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/auth/HttpBasicAuth.mustache
index 5b07cb907bb..a065cb1a90e 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/auth/HttpBasicAuth.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/auth/HttpBasicAuth.mustache
@@ -2,9 +2,9 @@ package {{invokerPackage}}.auth;
 
 import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
+import java.util.Base64;
 
 import org.springframework.http.HttpHeaders;
-import org.springframework.util.Base64Utils;
 import org.springframework.util.MultiValueMap;
 
 {{>generatedAnnotation}}
@@ -34,6 +34,6 @@ public class HttpBasicAuth implements Authentication {
             return;
         }
         String str = (username == null ? "" : username) + ":" + (password == null ? "" : password);
-        headerParams.add(HttpHeaders.AUTHORIZATION, "Basic " + Base64Utils.encodeToString(str.getBytes(StandardCharsets.UTF_8)));
+        headerParams.add(HttpHeaders.AUTHORIZATION, "Basic " + Base64.getEncoder().encodeToString(str.getBytes(StandardCharsets.UTF_8)));
     }
 }
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/auth/HttpBearerAuth.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/auth/HttpBearerAuth.mustache
index 1d1610c61c4..88fe9b384d5 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/auth/HttpBearerAuth.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/auth/HttpBearerAuth.mustache
@@ -4,7 +4,6 @@ import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
 
 import org.springframework.http.HttpHeaders;
-import org.springframework.util.Base64Utils;
 import org.springframework.util.MultiValueMap;
 
 {{>generatedAnnotation}}
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/webclient/auth/HttpBasicAuth.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/webclient/auth/HttpBasicAuth.mustache
index 5b07cb907bb..a065cb1a90e 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/webclient/auth/HttpBasicAuth.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/webclient/auth/HttpBasicAuth.mustache
@@ -2,9 +2,9 @@ package {{invokerPackage}}.auth;
 
 import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
+import java.util.Base64;
 
 import org.springframework.http.HttpHeaders;
-import org.springframework.util.Base64Utils;
 import org.springframework.util.MultiValueMap;
 
 {{>generatedAnnotation}}
@@ -34,6 +34,6 @@ public class HttpBasicAuth implements Authentication {
             return;
         }
         String str = (username == null ? "" : username) + ":" + (password == null ? "" : password);
-        headerParams.add(HttpHeaders.AUTHORIZATION, "Basic " + Base64Utils.encodeToString(str.getBytes(StandardCharsets.UTF_8)));
+        headerParams.add(HttpHeaders.AUTHORIZATION, "Basic " + Base64.getEncoder().encodeToString(str.getBytes(StandardCharsets.UTF_8)));
     }
 }
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/webclient/auth/HttpBearerAuth.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/webclient/auth/HttpBearerAuth.mustache
index 027c128f474..42765f0fd9b 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/webclient/auth/HttpBearerAuth.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/webclient/auth/HttpBearerAuth.mustache
@@ -4,7 +4,6 @@ import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
 
 import org.springframework.http.HttpHeaders;
-import org.springframework.util.Base64Utils;
 import org.springframework.util.MultiValueMap;
 
 {{>generatedAnnotation}}
diff --git a/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java b/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
index e5065280070..6e7e25a935f 100644
--- a/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
+++ b/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
@@ -2,9 +2,9 @@ package org.openapitools.client.auth;
 
 import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
+import java.util.Base64;
 
 import org.springframework.http.HttpHeaders;
-import org.springframework.util.Base64Utils;
 import org.springframework.util.MultiValueMap;
 
 @jakarta.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
@@ -34,6 +34,6 @@ public class HttpBasicAuth implements Authentication {
             return;
         }
         String str = (username == null ? "" : username) + ":" + (password == null ? "" : password);
-        headerParams.add(HttpHeaders.AUTHORIZATION, "Basic " + Base64Utils.encodeToString(str.getBytes(StandardCharsets.UTF_8)));
+        headerParams.add(HttpHeaders.AUTHORIZATION, "Basic " + Base64.getEncoder().encodeToString(str.getBytes(StandardCharsets.UTF_8)));
     }
 }
diff --git a/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java b/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
index 2e976576100..1e29bf9e4e3 100644
--- a/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
+++ b/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
@@ -4,7 +4,6 @@ import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
 
 import org.springframework.http.HttpHeaders;
-import org.springframework.util.Base64Utils;
 import org.springframework.util.MultiValueMap;
 
 @jakarta.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
diff --git a/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java b/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
index bbbbba67a47..ef2ee8d4340 100644
--- a/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
+++ b/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
@@ -2,9 +2,9 @@ package org.openapitools.client.auth;
 
 import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
+import java.util.Base64;
 
 import org.springframework.http.HttpHeaders;
-import org.springframework.util.Base64Utils;
 import org.springframework.util.MultiValueMap;
 
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
@@ -34,6 +34,6 @@ public class HttpBasicAuth implements Authentication {
             return;
         }
         String str = (username == null ? "" : username) + ":" + (password == null ? "" : password);
-        headerParams.add(HttpHeaders.AUTHORIZATION, "Basic " + Base64Utils.encodeToString(str.getBytes(StandardCharsets.UTF_8)));
+        headerParams.add(HttpHeaders.AUTHORIZATION, "Basic " + Base64.getEncoder().encodeToString(str.getBytes(StandardCharsets.UTF_8)));
     }
 }
diff --git a/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java b/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
index 299c05b12e0..6798c420a11 100644
--- a/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
+++ b/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
@@ -4,7 +4,6 @@ import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
 
 import org.springframework.http.HttpHeaders;
-import org.springframework.util.Base64Utils;
 import org.springframework.util.MultiValueMap;
 
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
index bbbbba67a47..ef2ee8d4340 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
@@ -2,9 +2,9 @@ package org.openapitools.client.auth;
 
 import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
+import java.util.Base64;
 
 import org.springframework.http.HttpHeaders;
-import org.springframework.util.Base64Utils;
 import org.springframework.util.MultiValueMap;
 
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
@@ -34,6 +34,6 @@ public class HttpBasicAuth implements Authentication {
             return;
         }
         String str = (username == null ? "" : username) + ":" + (password == null ? "" : password);
-        headerParams.add(HttpHeaders.AUTHORIZATION, "Basic " + Base64Utils.encodeToString(str.getBytes(StandardCharsets.UTF_8)));
+        headerParams.add(HttpHeaders.AUTHORIZATION, "Basic " + Base64.getEncoder().encodeToString(str.getBytes(StandardCharsets.UTF_8)));
     }
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
index 299c05b12e0..6798c420a11 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
@@ -4,7 +4,6 @@ import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
 
 import org.springframework.http.HttpHeaders;
-import org.springframework.util.Base64Utils;
 import org.springframework.util.MultiValueMap;
 
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
index bbbbba67a47..ef2ee8d4340 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
@@ -2,9 +2,9 @@ package org.openapitools.client.auth;
 
 import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
+import java.util.Base64;
 
 import org.springframework.http.HttpHeaders;
-import org.springframework.util.Base64Utils;
 import org.springframework.util.MultiValueMap;
 
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
@@ -34,6 +34,6 @@ public class HttpBasicAuth implements Authentication {
             return;
         }
         String str = (username == null ? "" : username) + ":" + (password == null ? "" : password);
-        headerParams.add(HttpHeaders.AUTHORIZATION, "Basic " + Base64Utils.encodeToString(str.getBytes(StandardCharsets.UTF_8)));
+        headerParams.add(HttpHeaders.AUTHORIZATION, "Basic " + Base64.getEncoder().encodeToString(str.getBytes(StandardCharsets.UTF_8)));
     }
 }
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
index 299c05b12e0..6798c420a11 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
@@ -4,7 +4,6 @@ import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
 
 import org.springframework.http.HttpHeaders;
-import org.springframework.util.Base64Utils;
 import org.springframework.util.MultiValueMap;
 
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
index e5065280070..6e7e25a935f 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
@@ -2,9 +2,9 @@ package org.openapitools.client.auth;
 
 import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
+import java.util.Base64;
 
 import org.springframework.http.HttpHeaders;
-import org.springframework.util.Base64Utils;
 import org.springframework.util.MultiValueMap;
 
 @jakarta.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
@@ -34,6 +34,6 @@ public class HttpBasicAuth implements Authentication {
             return;
         }
         String str = (username == null ? "" : username) + ":" + (password == null ? "" : password);
-        headerParams.add(HttpHeaders.AUTHORIZATION, "Basic " + Base64Utils.encodeToString(str.getBytes(StandardCharsets.UTF_8)));
+        headerParams.add(HttpHeaders.AUTHORIZATION, "Basic " + Base64.getEncoder().encodeToString(str.getBytes(StandardCharsets.UTF_8)));
     }
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
index 4b45dfdef0b..43fb8ac9acb 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
@@ -4,7 +4,6 @@ import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
 
 import org.springframework.http.HttpHeaders;
-import org.springframework.util.Base64Utils;
 import org.springframework.util.MultiValueMap;
 
 @jakarta.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
diff --git a/samples/client/petstore/java/webclient-nullable-arrays/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java b/samples/client/petstore/java/webclient-nullable-arrays/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
index bbbbba67a47..ef2ee8d4340 100644
--- a/samples/client/petstore/java/webclient-nullable-arrays/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
+++ b/samples/client/petstore/java/webclient-nullable-arrays/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
@@ -2,9 +2,9 @@ package org.openapitools.client.auth;
 
 import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
+import java.util.Base64;
 
 import org.springframework.http.HttpHeaders;
-import org.springframework.util.Base64Utils;
 import org.springframework.util.MultiValueMap;
 
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
@@ -34,6 +34,6 @@ public class HttpBasicAuth implements Authentication {
             return;
         }
         String str = (username == null ? "" : username) + ":" + (password == null ? "" : password);
-        headerParams.add(HttpHeaders.AUTHORIZATION, "Basic " + Base64Utils.encodeToString(str.getBytes(StandardCharsets.UTF_8)));
+        headerParams.add(HttpHeaders.AUTHORIZATION, "Basic " + Base64.getEncoder().encodeToString(str.getBytes(StandardCharsets.UTF_8)));
     }
 }
diff --git a/samples/client/petstore/java/webclient-nullable-arrays/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java b/samples/client/petstore/java/webclient-nullable-arrays/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
index 775bbf64c3b..b85cb250845 100644
--- a/samples/client/petstore/java/webclient-nullable-arrays/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
+++ b/samples/client/petstore/java/webclient-nullable-arrays/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
@@ -4,7 +4,6 @@ import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
 
 import org.springframework.http.HttpHeaders;
-import org.springframework.util.Base64Utils;
 import org.springframework.util.MultiValueMap;
 
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
index bbbbba67a47..ef2ee8d4340 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
@@ -2,9 +2,9 @@ package org.openapitools.client.auth;
 
 import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
+import java.util.Base64;
 
 import org.springframework.http.HttpHeaders;
-import org.springframework.util.Base64Utils;
 import org.springframework.util.MultiValueMap;
 
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
@@ -34,6 +34,6 @@ public class HttpBasicAuth implements Authentication {
             return;
         }
         String str = (username == null ? "" : username) + ":" + (password == null ? "" : password);
-        headerParams.add(HttpHeaders.AUTHORIZATION, "Basic " + Base64Utils.encodeToString(str.getBytes(StandardCharsets.UTF_8)));
+        headerParams.add(HttpHeaders.AUTHORIZATION, "Basic " + Base64.getEncoder().encodeToString(str.getBytes(StandardCharsets.UTF_8)));
     }
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
index 775bbf64c3b..b85cb250845 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
@@ -4,7 +4,6 @@ import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
 
 import org.springframework.http.HttpHeaders;
-import org.springframework.util.Base64Utils;
 import org.springframework.util.MultiValueMap;
 
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")