add colllectionFormat support to retrofit

Fix #1364

modules/swagger-codegen/src/main/resources/Java/libraries/retrofit/CollectionFormats.mustache

@@ -0,0 +1,95 @@
+package {{invokerPackage}};
+
+import java.util.Arrays;
+import java.util.List;
+
+public class CollectionFormats {
+    
+    public static class CSVParams {
+
+        protected List<String> params;
+        
+        public CSVParams() {
+        }
+        
+        public CSVParams(List<String> params) {
+            this.params = params;
+        }
+        
+        public CSVParams(String... params) {
+            this.params = Arrays.asList(params);
+        }
+
+        public List<String> getParams() {
+            return params;
+        }
+
+        public void setParams(List<String> params) {
+            this.params = params;
+        }
+        
+        @Override
+        public String toString() {
+            return String.join(",", params);
+        }
+        
+    }
+    
+    public static class SSVParams extends CSVParams {
+        
+        public SSVParams() {
+        }
+        
+        public SSVParams(List<String> params) {
+            super(params);
+        }
+
+        public SSVParams(String... params) {
+            super(params);
+        }
+
+        @Override
+        public String toString() {
+            return String.join(" ", params);
+        }
+    }
+    
+    public static class TSVParams extends CSVParams {
+        
+        public TSVParams() {
+        }
+        
+        public TSVParams(List<String> params) {
+            super(params);
+        }
+        
+        public TSVParams(String... params) {
+            super(params);
+        }
+
+        @Override
+        public String toString() {
+            return String.join("\t", params);
+        }
+    }
+    
+    public static class PIPESParams extends CSVParams {
+        
+        public PIPESParams() {
+        }
+        
+        public PIPESParams(List<String> params) {
+            super(params);
+        }
+        
+        public PIPESParams(String... params) {
+            super(params);
+        }
+
+        @Override
+        public String toString() {
+            return String.join("|", params);
+        }
+    }
+    
+}

modules/swagger-codegen/src/main/resources/Java/libraries/retrofit/api.mustache

@@ -1,5 +1,9 @@
 package {{package}};
 
+import {{invokerPackage}}.CollectionFormats.*;
+
+import {{modelPackage}}.*;
+
 import retrofit.Callback;
 import retrofit.http.*;
 import retrofit.mime.*;

modules/swagger-codegen/src/main/resources/Java/libraries/retrofit/queryParams.mustache

@@ -1 +1 @@
-{{#isQueryParam}}@Query("{{baseName}}") {{{dataType}}} {{paramName}}{{/isQueryParam}}
+{{#isQueryParam}}@Query("{{baseName}}") {{#collectionFormat}}{{#isCollectionFormatMulti}}{{{dataType}}}{{/isCollectionFormatMulti}}{{^isCollectionFormatMulti}}{{{collectionFormat.toUpperCase}}}Params{{/isCollectionFormatMulti}}{{/collectionFormat}}{{^collectionFormat}}{{{dataType}}}{{/collectionFormat}} {{paramName}}{{/isQueryParam}}