diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/ApiClient.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/ApiClient.mustache
index e48370f1539..f868eaa6dbf 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/ApiClient.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/ApiClient.mustache
@@ -34,6 +34,7 @@ import org.springframework.util.StringUtils;
 import org.springframework.web.client.RestClientException;
 import org.springframework.web.client.RestTemplate;
 import org.springframework.web.util.UriComponentsBuilder;
+import org.springframework.web.util.DefaultUriBuilderFactory;
 {{#threetenbp}}
 import org.threeten.bp.*;
 import com.fasterxml.jackson.datatype.threetenbp.ThreeTenModule;
@@ -622,6 +623,12 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
      * @return path with placeholders replaced by variables
      */
     public String expandPath(String pathTemplate, Map<String, Object> variables) {
+        // disable default URL encoding 
+        DefaultUriBuilderFactory uriBuilderFactory = new DefaultUriBuilderFactory();
+        uriBuilderFactory.setEncodingMode(DefaultUriBuilderFactory.EncodingMode.NONE);
+        final RestTemplate restTemplate = new RestTemplate();
+        restTemplate.setUriTemplateHandler(uriBuilderFactory);
+
         return restTemplate.getUriTemplateHandler().expand(pathTemplate, variables).toString();
     }
 
@@ -632,27 +639,33 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
      * @param uriParams The path parameters
      * return templatized query string
      */
-    private String generateQueryUri(MultiValueMap<String, String> queryParams, Map<String, Object> uriParams) {
+    public String generateQueryUri(MultiValueMap<String, String> queryParams, Map<String, Object> uriParams) {
         StringBuilder queryBuilder = new StringBuilder();
         queryParams.forEach((name, values) -> {
-            if (CollectionUtils.isEmpty(values)) {
-                if (queryBuilder.length() != 0) {
-                    queryBuilder.append('&');
-                }
-                queryBuilder.append(name);
-            } else {
-                int valueItemCounter = 0;
-                for (Object value : values) {
+            try {
+                final String encodedName = URLEncoder.encode(name.toString(), "UTF-8");
+                if (CollectionUtils.isEmpty(values)) {
                     if (queryBuilder.length() != 0) {
                         queryBuilder.append('&');
                     }
-                    queryBuilder.append(name);
-                    if (value != null) {
-                        String templatizedKey = name + valueItemCounter++;
-                        uriParams.put(templatizedKey, value.toString());
-                        queryBuilder.append('=').append("{").append(templatizedKey).append("}");
+                    queryBuilder.append(encodedName);
+                } else {
+                    int valueItemCounter = 0;
+                    for (Object value : values) {
+                        if (queryBuilder.length() != 0) {
+                            queryBuilder.append('&');
+                        }
+                        queryBuilder.append(encodedName);
+                        if (value != null) {
+                            String templatizedKey = encodedName + valueItemCounter++;
+                            final String encodedValue = URLEncoder.encode(value.toString(), "UTF-8");
+                            uriParams.put(templatizedKey, encodedValue);
+                            queryBuilder.append('=').append("{").append(templatizedKey).append("}");
+                        }
                     }
                 }
+            } catch (UnsupportedEncodingException e) {
+
             }
         });
         return queryBuilder.toString();
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/ApiClient.java
index 093e4897144..8e5e2933cec 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/ApiClient.java
@@ -30,6 +30,7 @@ import org.springframework.util.StringUtils;
 import org.springframework.web.client.RestClientException;
 import org.springframework.web.client.RestTemplate;
 import org.springframework.web.util.UriComponentsBuilder;
+import org.springframework.web.util.DefaultUriBuilderFactory;
 import org.threeten.bp.*;
 import com.fasterxml.jackson.datatype.threetenbp.ThreeTenModule;
 import org.springframework.http.converter.HttpMessageConverter;
@@ -578,6 +579,12 @@ public class ApiClient extends JavaTimeFormatter {
      * @return path with placeholders replaced by variables
      */
     public String expandPath(String pathTemplate, Map<String, Object> variables) {
+        // disable default URL encoding 
+        DefaultUriBuilderFactory uriBuilderFactory = new DefaultUriBuilderFactory();
+        uriBuilderFactory.setEncodingMode(DefaultUriBuilderFactory.EncodingMode.NONE);
+        final RestTemplate restTemplate = new RestTemplate();
+        restTemplate.setUriTemplateHandler(uriBuilderFactory);
+
         return restTemplate.getUriTemplateHandler().expand(pathTemplate, variables).toString();
     }
 
@@ -588,27 +595,33 @@ public class ApiClient extends JavaTimeFormatter {
      * @param uriParams The path parameters
      * return templatized query string
      */
-    private String generateQueryUri(MultiValueMap<String, String> queryParams, Map<String, Object> uriParams) {
+    public String generateQueryUri(MultiValueMap<String, String> queryParams, Map<String, Object> uriParams) {
         StringBuilder queryBuilder = new StringBuilder();
         queryParams.forEach((name, values) -> {
-            if (CollectionUtils.isEmpty(values)) {
-                if (queryBuilder.length() != 0) {
-                    queryBuilder.append('&');
-                }
-                queryBuilder.append(name);
-            } else {
-                int valueItemCounter = 0;
-                for (Object value : values) {
+            try {
+                final String encodedName = URLEncoder.encode(name.toString(), "UTF-8");
+                if (CollectionUtils.isEmpty(values)) {
                     if (queryBuilder.length() != 0) {
                         queryBuilder.append('&');
                     }
-                    queryBuilder.append(name);
-                    if (value != null) {
-                        String templatizedKey = name + valueItemCounter++;
-                        uriParams.put(templatizedKey, value.toString());
-                        queryBuilder.append('=').append("{").append(templatizedKey).append("}");
+                    queryBuilder.append(encodedName);
+                } else {
+                    int valueItemCounter = 0;
+                    for (Object value : values) {
+                        if (queryBuilder.length() != 0) {
+                            queryBuilder.append('&');
+                        }
+                        queryBuilder.append(encodedName);
+                        if (value != null) {
+                            String templatizedKey = encodedName + valueItemCounter++;
+                            final String encodedValue = URLEncoder.encode(value.toString(), "UTF-8");
+                            uriParams.put(templatizedKey, encodedValue);
+                            queryBuilder.append('=').append("{").append(templatizedKey).append("}");
+                        }
                     }
                 }
+            } catch (UnsupportedEncodingException e) {
+
             }
         });
         return queryBuilder.toString();
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/test/java/org/openapitools/client/ApiClientTest.java b/samples/client/petstore/java/resttemplate-withXml/src/test/java/org/openapitools/client/ApiClientTest.java
new file mode 100644
index 00000000000..4b3a63c3e26
--- /dev/null
+++ b/samples/client/petstore/java/resttemplate-withXml/src/test/java/org/openapitools/client/ApiClientTest.java
@@ -0,0 +1,31 @@
+package org.openapitools.client;
+
+import static org.hamcrest.CoreMatchers.*;
+import static org.junit.Assert.*;
+
+import java.util.*;
+import org.junit.*;
+import org.springframework.util.MultiValueMap;
+import org.springframework.util.LinkedMultiValueMap;
+
+public class ApiClientTest {
+    ApiClient apiClient;
+
+    @Before
+    public void setup() {
+        apiClient = new ApiClient();
+    }
+
+    /**
+     * Test uri encoding when params contains comma
+     */
+    @Test
+    public void testUriEncoderWithComma() {
+        Map<String,Object> uriParams = new HashMap<>();
+        MultiValueMap<String, String> queryParams = new LinkedMultiValueMap<String, String>();
+        queryParams.add("key", "val,comma");
+        apiClient.generateQueryUri(queryParams, uriParams);
+
+        assertEquals("/key=val%2Ccomma", apiClient.expandPath("/key={key0}", uriParams));
+    }
+}
\ No newline at end of file
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/ApiClient.java
index 89f43f67cc1..42d81a59578 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/ApiClient.java
@@ -25,6 +25,7 @@ import org.springframework.util.StringUtils;
 import org.springframework.web.client.RestClientException;
 import org.springframework.web.client.RestTemplate;
 import org.springframework.web.util.UriComponentsBuilder;
+import org.springframework.web.util.DefaultUriBuilderFactory;
 import org.threeten.bp.*;
 import com.fasterxml.jackson.datatype.threetenbp.ThreeTenModule;
 import org.springframework.http.converter.HttpMessageConverter;
@@ -573,6 +574,12 @@ public class ApiClient extends JavaTimeFormatter {
      * @return path with placeholders replaced by variables
      */
     public String expandPath(String pathTemplate, Map<String, Object> variables) {
+        // disable default URL encoding 
+        DefaultUriBuilderFactory uriBuilderFactory = new DefaultUriBuilderFactory();
+        uriBuilderFactory.setEncodingMode(DefaultUriBuilderFactory.EncodingMode.NONE);
+        final RestTemplate restTemplate = new RestTemplate();
+        restTemplate.setUriTemplateHandler(uriBuilderFactory);
+
         return restTemplate.getUriTemplateHandler().expand(pathTemplate, variables).toString();
     }
 
@@ -583,27 +590,33 @@ public class ApiClient extends JavaTimeFormatter {
      * @param uriParams The path parameters
      * return templatized query string
      */
-    private String generateQueryUri(MultiValueMap<String, String> queryParams, Map<String, Object> uriParams) {
+    public String generateQueryUri(MultiValueMap<String, String> queryParams, Map<String, Object> uriParams) {
         StringBuilder queryBuilder = new StringBuilder();
         queryParams.forEach((name, values) -> {
-            if (CollectionUtils.isEmpty(values)) {
-                if (queryBuilder.length() != 0) {
-                    queryBuilder.append('&');
-                }
-                queryBuilder.append(name);
-            } else {
-                int valueItemCounter = 0;
-                for (Object value : values) {
+            try {
+                final String encodedName = URLEncoder.encode(name.toString(), "UTF-8");
+                if (CollectionUtils.isEmpty(values)) {
                     if (queryBuilder.length() != 0) {
                         queryBuilder.append('&');
                     }
-                    queryBuilder.append(name);
-                    if (value != null) {
-                        String templatizedKey = name + valueItemCounter++;
-                        uriParams.put(templatizedKey, value.toString());
-                        queryBuilder.append('=').append("{").append(templatizedKey).append("}");
+                    queryBuilder.append(encodedName);
+                } else {
+                    int valueItemCounter = 0;
+                    for (Object value : values) {
+                        if (queryBuilder.length() != 0) {
+                            queryBuilder.append('&');
+                        }
+                        queryBuilder.append(encodedName);
+                        if (value != null) {
+                            String templatizedKey = encodedName + valueItemCounter++;
+                            final String encodedValue = URLEncoder.encode(value.toString(), "UTF-8");
+                            uriParams.put(templatizedKey, encodedValue);
+                            queryBuilder.append('=').append("{").append(templatizedKey).append("}");
+                        }
                     }
                 }
+            } catch (UnsupportedEncodingException e) {
+
             }
         });
         return queryBuilder.toString();
diff --git a/samples/client/petstore/java/resttemplate/src/test/java/org/openapitools/client/ApiClientTest.java b/samples/client/petstore/java/resttemplate/src/test/java/org/openapitools/client/ApiClientTest.java
new file mode 100644
index 00000000000..4b3a63c3e26
--- /dev/null
+++ b/samples/client/petstore/java/resttemplate/src/test/java/org/openapitools/client/ApiClientTest.java
@@ -0,0 +1,31 @@
+package org.openapitools.client;
+
+import static org.hamcrest.CoreMatchers.*;
+import static org.junit.Assert.*;
+
+import java.util.*;
+import org.junit.*;
+import org.springframework.util.MultiValueMap;
+import org.springframework.util.LinkedMultiValueMap;
+
+public class ApiClientTest {
+    ApiClient apiClient;
+
+    @Before
+    public void setup() {
+        apiClient = new ApiClient();
+    }
+
+    /**
+     * Test uri encoding when params contains comma
+     */
+    @Test
+    public void testUriEncoderWithComma() {
+        Map<String,Object> uriParams = new HashMap<>();
+        MultiValueMap<String, String> queryParams = new LinkedMultiValueMap<String, String>();
+        queryParams.add("key", "val,comma");
+        apiClient.generateQueryUri(queryParams, uriParams);
+
+        assertEquals("/key=val%2Ccomma", apiClient.expandPath("/key={key0}", uriParams));
+    }
+}
\ No newline at end of file