[JAVA][FEIGN] Removing hardcoded HTTP Client which is causing performance issues (#21085)

* [JAVA][FEIGN] Removing hardcoded HTTP Client

Fixing performance issues

* Updating samples for Java Feign performance betterment changes

* added APIClient.java for feign-hc5

Author: sushma3690

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

@@ -9,12 +9,6 @@ import java.util.logging.Level;
 import java.util.logging.Logger;
 
 {{#jackson}}
-{{#feign-okhttp}}
-import feign.okhttp.OkHttpClient;
-{{/feign-okhttp}}
-{{#feign-hc5}}
-import feign.hc5.ApacheHttp5Client;
-{{/feign-hc5}}
 import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializationFeature;
@@ -76,12 +70,6 @@ public class ApiClient {
     {{#jackson}}
     objectMapper = createObjectMapper();
     feignBuilder = Feign.builder()
-                {{#feign-okhttp}}
-                .client(new OkHttpClient())
-                {{/feign-okhttp}}
-                {{#feign-hc5}}
-                .client(new ApacheHttp5Client())
-                {{/feign-hc5}}
                 .encoder(new FormEncoder(new JacksonEncoder(objectMapper)))
                 .decoder(new ApiResponseDecoder(objectMapper))
                 {{#hasOAuthMethods}}

samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/ApiClient.java

@@ -19,7 +19,6 @@
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
-import feign.hc5.ApacheHttp5Client;
 import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializationFeature;
@@ -60,7 +59,6 @@ public ApiClient() {
     apiAuthorizations = new LinkedHashMap<String, RequestInterceptor>();
     objectMapper = createObjectMapper();
     feignBuilder = Feign.builder()
-                .client(new ApacheHttp5Client())
                 .encoder(new FormEncoder(new JacksonEncoder(objectMapper)))
                 .decoder(new ApiResponseDecoder(objectMapper))
                 .errorDecoder(new ApiErrorDecoder())

samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/ApiClient.java

@@ -19,7 +19,6 @@
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
-import feign.okhttp.OkHttpClient;
 import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializationFeature;
@@ -59,7 +58,6 @@ public ApiClient() {
     apiAuthorizations = new LinkedHashMap<String, RequestInterceptor>();
     objectMapper = createObjectMapper();
     feignBuilder = Feign.builder()
-                .client(new OkHttpClient())
                 .encoder(new FormEncoder(new JacksonEncoder(objectMapper)))
                 .decoder(new ApiResponseDecoder(objectMapper))
                 .errorDecoder(new ApiErrorDecoder())

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

@@ -19,7 +19,6 @@
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
-import feign.okhttp.OkHttpClient;
 import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializationFeature;
@@ -60,7 +59,6 @@ public ApiClient() {
     apiAuthorizations = new LinkedHashMap<String, RequestInterceptor>();
     objectMapper = createObjectMapper();
     feignBuilder = Feign.builder()
-                .client(new OkHttpClient())
                 .encoder(new FormEncoder(new JacksonEncoder(objectMapper)))
                 .decoder(new ApiResponseDecoder(objectMapper))
                 .errorDecoder(new ApiErrorDecoder())