feat: create json mapper

Signed-off-by: Otavio Santana <[email protected]>

core/src/main/java/expert/os/harperdb/JSONMapper.java

@@ -1,11 +1,14 @@
 package expert.os.harperdb;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializationFeature;
 import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
 
 import java.io.IOException;
+import java.util.Collections;
+import java.util.List;
 import java.util.Optional;
 
 enum JSONMapper {
@@ -26,12 +29,23 @@ byte[] writeValueAsBytes(Object value) {
  }
  }
 
- <T> Optional<T> readSingleValue(byte[] bytes, Class<T> valueType) {
+ <T> Optional<T> readSingleValue(byte[] bytes, Class<T> type) {
  try {
  if(bytes == null || bytes.length == 0){
  return Optional.empty();
  }
- return Optional.of(mapper.readValue(bytes, valueType));
+ return Optional.of(mapper.readValue(bytes, type));
+ } catch (IOException exception) {
+ throw new HarperDBException("There is an issue to read from json value", exception);
+ }
+ }
+
+ <T> List<T> readValue(byte[] bytes, Class<T> type) {
+ try {
+ if(bytes == null || bytes.length == 0){
+ return Collections.emptyList();
+ }
+ return mapper.readValue(bytes, new TypeReference<>() {});
  } catch (IOException exception) {
  throw new HarperDBException("There is an issue to read from json value", exception);
  }

core/src/main/java/expert/os/harperdb/Server.java

@@ -5,6 +5,8 @@
 import java.net.http.HttpClient;
 import java.net.http.HttpRequest;
 import java.net.http.HttpResponse;
+import java.util.Collections;
+import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
 
@@ -105,6 +107,23 @@ <T> Optional<T> singleResult(Operation operation, Class<T> type){
  }
  }
 
+ <T> List<T> result(Operation operation, Class<T> type){
+ HttpRequest request = createRequest()
+ .POST(ofByteArray(INSTANCE.writeValueAsBytes(operation)))
+ .build();
+ try {
+ HttpResponse<byte[]> response = client.send(request, HttpResponse.BodyHandlers.ofByteArray());
+ if(HttpStatus.OK.isEquals(response)){
+ byte[] body = response.body();
+ return INSTANCE.readValue(body, type);
+ } else {
+ return Collections.emptyList();
+ }
+ } catch (IOException| InterruptedException e) {
+ throw new HarperDBException("There is an issue to execute the operation: " + operation + "message: ", e);
+ }
+ }
+
 
  HttpRequest.Builder createRequest() {
  return HttpRequest.newBuilder()