[java] Jersey2 and resttemplate do not correctly send defaultCookies (#4821)

* Java/Jersey2 sends defaultCookies

* Send cookie value instead of [value] (resttemplate)

* Improve the javadoc string

modules/openapi-generator/src/main/resources/Java/libraries/jersey2/ApiClient.mustache

@@ -715,6 +715,13 @@ public class ApiClient {
       }
     }
 
+    for (Entry<String, String> entry : defaultCookieMap.entrySet()) {
+      String value = entry.getValue();
+      if (value != null) {
+        invocationBuilder = invocationBuilder.cookie(entry.getKey(), value);
+      }
+    }
+
     for (Entry<String, String> entry : defaultHeaderMap.entrySet()) {
       String key = entry.getKey();
       if (!headerParams.containsKey(key)) {

modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/ApiClient.mustache

@@ -659,14 +659,20 @@ public class ApiClient {
         }
     }
 
+    /**
+     * Build cookie header. Keeps a single value per cookie (as per <a href="https://tools.ietf.org/html/rfc6265#section-5.3">
+     * RFC6265 section 5.3</a>).
+     *
+     * @param cookies map all cookies
+     * @return header string for cookies.
+     */
     private String buildCookieHeader(MultiValueMap<String, String> cookies) {
         final StringBuilder cookieValue = new StringBuilder();
         String delimiter = "";
         for (final Map.Entry<String, List<String>> entry : cookies.entrySet()) {
-            for (String value : entry.getValue()) {
+            final String value = entry.getValue().get(entry.getValue().size() - 1);
-                cookieValue.append(String.format("%s%s=%s", delimiter, entry.getKey(), entry.getValue()));
+            cookieValue.append(String.format("%s%s=%s", delimiter, entry.getKey(), value));
-                delimiter = "; ";
+            delimiter = "; ";
-            }
         }
         return cookieValue.toString();
     }

samples/client/petstore/java/jersey2-java6/src/main/java/org/openapitools/client/ApiClient.java

@@ -699,6 +699,13 @@ public class ApiClient {
       }
     }
 
+    for (Entry<String, String> entry : defaultCookieMap.entrySet()) {
+      String value = entry.getValue();
+      if (value != null) {
+        invocationBuilder = invocationBuilder.cookie(entry.getKey(), value);
+      }
+    }
+
     for (Entry<String, String> entry : defaultHeaderMap.entrySet()) {
       String key = entry.getKey();
       if (!headerParams.containsKey(key)) {

samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/ApiClient.java

@@ -699,6 +699,13 @@ public class ApiClient {
       }
     }
 
+    for (Entry<String, String> entry : defaultCookieMap.entrySet()) {
+      String value = entry.getValue();
+      if (value != null) {
+        invocationBuilder = invocationBuilder.cookie(entry.getKey(), value);
+      }
+    }
+
     for (Entry<String, String> entry : defaultHeaderMap.entrySet()) {
       String key = entry.getKey();
       if (!headerParams.containsKey(key)) {

samples/client/petstore/java/jersey2/src/main/java/org/openapitools/client/ApiClient.java

@@ -699,6 +699,13 @@ public class ApiClient {
       }
     }
 
+    for (Entry<String, String> entry : defaultCookieMap.entrySet()) {
+      String value = entry.getValue();
+      if (value != null) {
+        invocationBuilder = invocationBuilder.cookie(entry.getKey(), value);
+      }
+    }
+
     for (Entry<String, String> entry : defaultHeaderMap.entrySet()) {
       String key = entry.getKey();
       if (!headerParams.containsKey(key)) {

samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/ApiClient.java

@@ -647,14 +647,20 @@ public class ApiClient {
         }
     }
 
+    /**
+     * Build cookie header. Keeps a single value per cookie (as per <a href="https://tools.ietf.org/html/rfc6265#section-5.3">
+     * RFC6265 section 5.3</a>).
+     *
+     * @param cookies map all cookies
+     * @return header string for cookies.
+     */
     private String buildCookieHeader(MultiValueMap<String, String> cookies) {
         final StringBuilder cookieValue = new StringBuilder();
         String delimiter = "";
         for (final Map.Entry<String, List<String>> entry : cookies.entrySet()) {
-            for (String value : entry.getValue()) {
+            final String value = entry.getValue().get(entry.getValue().size() - 1);
-                cookieValue.append(String.format("%s%s=%s", delimiter, entry.getKey(), entry.getValue()));
+            cookieValue.append(String.format("%s%s=%s", delimiter, entry.getKey(), value));
-                delimiter = "; ";
+            delimiter = "; ";
-            }
         }
         return cookieValue.toString();
     }

samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/ApiClient.java

@@ -642,14 +642,20 @@ public class ApiClient {
         }
     }
 
+    /**
+     * Build cookie header. Keeps a single value per cookie (as per <a href="https://tools.ietf.org/html/rfc6265#section-5.3">
+     * RFC6265 section 5.3</a>).
+     *
+     * @param cookies map all cookies
+     * @return header string for cookies.
+     */
     private String buildCookieHeader(MultiValueMap<String, String> cookies) {
         final StringBuilder cookieValue = new StringBuilder();
         String delimiter = "";
         for (final Map.Entry<String, List<String>> entry : cookies.entrySet()) {
-            for (String value : entry.getValue()) {
+            final String value = entry.getValue().get(entry.getValue().size() - 1);
-                cookieValue.append(String.format("%s%s=%s", delimiter, entry.getKey(), entry.getValue()));
+            cookieValue.append(String.format("%s%s=%s", delimiter, entry.getKey(), value));
-                delimiter = "; ";
+            delimiter = "; ";
-            }
         }
         return cookieValue.toString();
     }