[Java][Feign] Use OpenFeign, update Feign to v9.3.1, better handling of dates in parameters

modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/AbstractJavaCodegen.java

@@ -273,8 +273,7 @@ public void processOpts() {
 
             importMapping.put("LocalDate", "org.joda.time.LocalDate");
             importMapping.put("DateTime", "org.joda.time.DateTime");
-        }
-        else if (dateLibrary.startsWith("java8")) {
+        } else if (dateLibrary.startsWith("java8")) {
             additionalProperties.put("java8", "true");
             typeMapping.put("date", "LocalDate");
             importMapping.put("LocalDate", "java.time.LocalDate");
@@ -285,6 +284,8 @@ else if (dateLibrary.startsWith("java8")) {
                 typeMapping.put("DateTime", "OffsetDateTime");
                 importMapping.put("OffsetDateTime", "java.time.OffsetDateTime");
             }
+        } else if (dateLibrary.equals("legacy")) {
+            additionalProperties.put("legacyDates", "true");
         }
     }
 

modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/JavaClientCodegen.java

@@ -136,8 +136,8 @@ public void processOpts() {
         }
 
         if ("feign".equals(getLibrary())) {
-            supportingFiles.add(new SupportingFile("FormAwareEncoder.mustache", invokerFolder, "FormAwareEncoder.java"));
             additionalProperties.put("jackson", "true");
+            supportingFiles.add(new SupportingFile("ParamExpander.mustache", invokerFolder, "ParamExpander.java"));
         } else if ("okhttp-gson".equals(getLibrary()) || StringUtils.isEmpty(getLibrary())) {
             // the "okhttp-gson" library template requires "ApiCallback.mustache" for async call
             supportingFiles.add(new SupportingFile("ApiCallback.mustache", invokerFolder, "ApiCallback.java"));

modules/swagger-codegen/src/main/resources/Java/libraries/feign/ApiClient.mustache

@@ -18,6 +18,7 @@ import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
 
 import feign.Feign;
 import feign.RequestInterceptor;
+import feign.form.FormEncoder;
 import feign.jackson.JacksonDecoder;
 import feign.jackson.JacksonEncoder;
 import feign.slf4j.Slf4jLogger;
@@ -37,7 +38,7 @@ public class ApiClient {
     objectMapper = createObjectMapper();
     apiAuthorizations = new LinkedHashMap<String, RequestInterceptor>();
     feignBuilder = Feign.builder()
-                .encoder(new FormAwareEncoder(new JacksonEncoder(objectMapper)))
+                .encoder(new FormEncoder(new JacksonEncoder(objectMapper)))
                 .decoder(new JacksonDecoder(objectMapper))
                 .logger(new Slf4jLogger());
   }

modules/swagger-codegen/src/main/resources/Java/libraries/feign/ParamExpander.mustache

@@ -0,0 +1,22 @@
+package {{invokerPackage}};
+
+import feign.Param;
+
+import java.text.DateFormat;
+import java.util.Date;
+
+/**
+ * Param Expander to convert {@link Date} to RFC3339
+ */
+public class ParamExpander implements Param.Expander {
+
+  private static final DateFormat dateformat = new RFC3339DateFormat();
+
+  @Override
+  public String expand(Object value) {
+    if (value instanceof Date) {
+      return dateformat.format(value);
+    }
+    return value.toString();
+  }
+}

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

@@ -1,6 +1,9 @@
 package {{package}};
 
 import {{invokerPackage}}.ApiClient;
+{{#legacyDates}}
+import {{invokerPackage}}.ParamExpander;
+{{/legacyDates}}
 
 {{#imports}}import {{import}};
 {{/imports}}
@@ -25,12 +28,12 @@ public interface {{classname}} extends ApiClient.Api {
    */
   @RequestLine("{{httpMethod}} {{{path}}}{{#hasQueryParams}}?{{/hasQueryParams}}{{#queryParams}}{{baseName}}={{=<% %>=}}{<%paramName%>}<%={{ }}=%>{{#hasMore}}&{{/hasMore}}{{/queryParams}}")
   @Headers({
-    "Content-type: {{vendorExtensions.x-contentType}}",
+    "Content-Type: {{vendorExtensions.x-contentType}}",
     "Accept: {{vendorExtensions.x-accepts}}",{{#headerParams}}
     "{{baseName}}: {{=<% %>=}}{<%paramName%>}<%={{ }}=%>"{{#hasMore}},
     {{/hasMore}}{{/headerParams}}
   })
-  {{#returnType}}{{{returnType}}} {{/returnType}}{{^returnType}}void {{/returnType}}{{nickname}}({{#allParams}}{{^isBodyParam}}@Param("{{paramName}}") {{/isBodyParam}}{{{dataType}}} {{paramName}}{{#hasMore}}, {{/hasMore}}{{/allParams}});
+  {{#returnType}}{{{returnType}}} {{/returnType}}{{^returnType}}void {{/returnType}}{{nickname}}({{#allParams}}{{^isBodyParam}}{{^legacyDates}}@Param("{{paramName}}") {{/legacyDates}}{{#legacyDates}}@Param(value="{{paramName}}", expander=ParamExpander.class) {{/legacyDates}}{{/isBodyParam}}{{{dataType}}} {{paramName}}{{#hasMore}}, {{/hasMore}}{{/allParams}});
   {{/operation}}
 {{/operations}}
 }

modules/swagger-codegen/src/main/resources/Java/libraries/feign/build.gradle.mustache

@@ -97,6 +97,7 @@ ext {
     swagger_annotations_version = "1.5.9"
     jackson_version = "2.7.5"
     feign_version = "8.17.0"
+    feign_form_version = "2.0.2"
     junit_version = "4.12"
     oltu_version = "1.0.1"
 }
@@ -106,6 +107,7 @@ dependencies {
     compile "com.netflix.feign:feign-core:$feign_version"
     compile "com.netflix.feign:feign-jackson:$feign_version"
     compile "com.netflix.feign:feign-slf4j:$feign_version"
+    compile "io.github.openfeign.form:feign-form:$feign_form_version"
     compile "com.fasterxml.jackson.core:jackson-core:$jackson_version"
     compile "com.fasterxml.jackson.core:jackson-annotations:$jackson_version"
     compile "com.fasterxml.jackson.core:jackson-databind:$jackson_version"

modules/swagger-codegen/src/main/resources/Java/libraries/feign/build.sbt.mustache

@@ -13,6 +13,7 @@ lazy val root = (project in file(".")).
       "com.netflix.feign" % "feign-core" % "8.16.0" % "compile",
       "com.netflix.feign" % "feign-jackson" % "8.17.0" % "compile",
       "com.netflix.feign" % "feign-slf4j" % "8.16.0" % "compile",
+      "io.github.openfeign.form" % "feign-form" % "2.0.2" % "compile",
       "com.fasterxml.jackson.core" % "jackson-core" % "2.7.5" % "compile",
       "com.fasterxml.jackson.core" % "jackson-annotations" % "2.7.5" % "compile",
       "com.fasterxml.jackson.core" % "jackson-databind" % "2.7.5" % "compile",

modules/swagger-codegen/src/main/resources/Java/libraries/feign/pom.mustache

@@ -125,6 +125,11 @@
         <artifactId>feign-slf4j</artifactId>
         <version>${feign-version}</version>
     </dependency>
+    <dependency>
+        <groupId>io.github.openfeign.form</groupId>
+        <artifactId>feign-form</artifactId>
+        <version>${feign-form-version}</version>
+    </dependency>
 
     <!-- JSON processing: jackson -->
     <dependency>
@@ -167,6 +172,7 @@
     <maven.compiler.target>${java.version}</maven.compiler.target>
     <swagger-core-version>1.5.9</swagger-core-version>
     <feign-version>8.17.0</feign-version>
+    <feign-form-version>2.0.2</feign-form-version>
     <jackson-version>2.7.5</jackson-version>
     <junit-version>4.12</junit-version>
     <maven-plugin-version>1.0.0</maven-plugin-version>

samples/client/petstore/java/feign/build.gradle

@@ -97,6 +97,7 @@ ext {
     swagger_annotations_version = "1.5.9"
     jackson_version = "2.7.5"
     feign_version = "8.17.0"
+    feign_form_version = "2.0.2"
     junit_version = "4.12"
     oltu_version = "1.0.1"
 }
@@ -106,6 +107,7 @@ dependencies {
     compile "com.netflix.feign:feign-core:$feign_version"
     compile "com.netflix.feign:feign-jackson:$feign_version"
     compile "com.netflix.feign:feign-slf4j:$feign_version"
+    compile "io.github.openfeign.form:feign-form:$feign_form_version"
     compile "com.fasterxml.jackson.core:jackson-core:$jackson_version"
     compile "com.fasterxml.jackson.core:jackson-annotations:$jackson_version"
     compile "com.fasterxml.jackson.core:jackson-databind:$jackson_version"

samples/client/petstore/java/feign/build.sbt

@@ -13,6 +13,7 @@ lazy val root = (project in file(".")).
       "com.netflix.feign" % "feign-core" % "8.16.0" % "compile",
       "com.netflix.feign" % "feign-jackson" % "8.17.0" % "compile",
       "com.netflix.feign" % "feign-slf4j" % "8.16.0" % "compile",
+      "io.github.openfeign.form" % "feign-form" % "2.0.2" % "compile",
       "com.fasterxml.jackson.core" % "jackson-core" % "2.7.5" % "compile",
       "com.fasterxml.jackson.core" % "jackson-annotations" % "2.7.5" % "compile",
       "com.fasterxml.jackson.core" % "jackson-databind" % "2.7.5" % "compile",