Remove the option to support JDK7 from Java generator and templates (#11547)

* remove java8 from java client generator and templates

* update tests

* remove threetenbp

* update spring templates to remove java8

* remove java8 from jaxrs template

* fix jaxrs spec

* fix feign

* remove CustomInstantDeserializer.java

* fix jersey1

* fix undertow

* various update

* fix jaxrs jersey1

* fix java inflector

* fix jaxrs cxf

* add new files

* update doc

samples/client/petstore/java/feign/src/test/java/org/openapitools/client/api/FakeApiTest.java

@@ -6,8 +6,8 @@ import org.openapitools.client.model.Client;
 import java.io.File;
 import org.openapitools.client.model.FileSchemaTestClass;
 import org.openapitools.client.model.HealthCheckResult;
-import org.threeten.bp.LocalDate;
-import org.threeten.bp.OffsetDateTime;
+import java.time.LocalDate;
+import java.time.OffsetDateTime;
 import org.openapitools.client.model.OuterComposite;
 import org.openapitools.client.model.OuterObjectWithEnumProperty;
 import org.openapitools.client.model.Pet;
@@ -376,7 +376,9 @@ class FakeApiTest {
         List<String> http = null;
         List<String> url = null;
         List<String> context = null;
-        // api.testQueryParameterCollectionFormat(pipe, ioutil, http, url, context);
+        String allowEmpty = null;
+        Map<String, String> language = null;
+        // api.testQueryParameterCollectionFormat(pipe, ioutil, http, url, context, allowEmpty, language);
 
         // TODO: test validations
     }
@@ -396,7 +398,9 @@ class FakeApiTest {
             .ioutil(null)
             .http(null)
             .url(null)
-            .context(null);
+            .context(null)
+            .language(null)
+            .allowEmpty(null);
         // api.testQueryParameterCollectionFormat(queryParams);
 
     // TODO: test validations

samples/client/petstore/java/feign/src/test/java/org/openapitools/client/api/StoreApiTest.java

@@ -7,9 +7,9 @@ import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 import org.openapitools.client.ApiClient;
 import org.openapitools.client.model.Order;
-import org.threeten.bp.OffsetDateTime;
-import org.threeten.bp.ZoneOffset;
 
+import java.time.OffsetDateTime;
+import java.time.ZoneOffset;
 import java.util.Map;
 
 import static com.github.tomakehurst.wiremock.client.WireMock.*;

samples/client/petstore/java/feign/src/test/java/org/openapitools/client/model/FormatTestTest.java

@@ -23,8 +23,6 @@ import io.swagger.annotations.ApiModelProperty;
 import java.io.File;
 import java.math.BigDecimal;
 import java.util.UUID;
-import org.threeten.bp.LocalDate;
-import org.threeten.bp.OffsetDateTime;
 import org.junit.jupiter.api.Test;
 
 

samples/client/petstore/java/feign/src/test/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClassTest.java

@@ -25,7 +25,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.UUID;
 import org.openapitools.client.model.Animal;
-import org.threeten.bp.OffsetDateTime;
 import org.junit.jupiter.api.Test;
 
 

samples/client/petstore/java/feign/src/test/java/org/openapitools/client/model/NullableClassTest.java

@@ -25,8 +25,6 @@ import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import org.threeten.bp.LocalDate;
-import org.threeten.bp.OffsetDateTime;
 import com.fasterxml.jackson.annotation.JsonIgnore;
 import org.openapitools.jackson.nullable.JsonNullable;
 import java.util.NoSuchElementException;

samples/client/petstore/java/feign/src/test/java/org/openapitools/client/model/OrderTest.java

@@ -20,7 +20,6 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
-import org.threeten.bp.OffsetDateTime;
 import org.junit.jupiter.api.Test;