com.github.tonivade.resp.protocol.RespSerializer Maven / Gradle / Ivy

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/*
 * Copyright (c) 2016-2017, Antonio Gabriel Muñoz Conejo 
 * Distributed under the terms of the MIT License
 */
package com.github.tonivade.resp.protocol;

import static com.github.tonivade.resp.protocol.RedisToken.string;
import static java.util.stream.Collectors.toList;
import static javaslang.API.$;
import static javaslang.API.Case;
import static javaslang.API.Match;
import static javaslang.Predicates.instanceOf;

import java.lang.reflect.Field;
import java.util.Collection;
import java.util.Map;
import java.util.function.Predicate;
import java.util.stream.Stream;

import com.github.tonivade.resp.protocol.RedisToken.ArrayRedisToken;
import com.github.tonivade.resp.protocol.RedisToken.StringRedisToken;

import javaslang.control.Try;

public class RespSerializer {

  public RedisToken getValue(Object object) {
    return Match(object).of(
        Case(isPrimitive(), this::getStringValue),
        Case(instanceOf(Object[].class), this::getArrayValue),
        Case(instanceOf(Number.class), this::getStringValue),
        Case(instanceOf(String.class), this::getStringValue),
        Case(instanceOf(Collection.class), this::getCollectionValue),
        Case(instanceOf(Map.class), this::getMapValue),
        Case($(), this::getObjectValue));
  }

  private ArrayRedisToken getMapValue(Map map) {
    return RedisToken.array(map.entrySet().stream()
        .flatMap(entry -> Stream.of(getValue(entry.getKey()), getValue(entry.getValue())))
        .collect(toList()));
  }

  private ArrayRedisToken getCollectionValue(Collection collection) {
    return RedisToken.array(collection.stream().map(this::getValue).collect(toList()));
  }

  private ArrayRedisToken getArrayValue(Object[] array) {
    return RedisToken.array(Stream.of(array).map(this::getValue).collect(toList()));
  }

  private ArrayRedisToken getObjectValue(Object object) {
    return RedisToken.array(Stream.of(object.getClass().getDeclaredFields())
        .filter(field -> !field.getName().startsWith("$"))
        .flatMap(field -> Stream.of(string(field.getName()), getValue(tryGetFieldValue(object, field))))
        .collect(toList()));
  }

  private Object tryGetFieldValue(Object object, Field field) {
    return Try.of(() -> getFieldValue(object, field)).get();
  }

  private Object getFieldValue(Object object, Field field) throws IllegalArgumentException, IllegalAccessException {
    field.setAccessible(true);
    return field.get(object);
  }

  private StringRedisToken getStringValue(Object value) {
    return string(String.valueOf(value));
  }

  private Predicate isPrimitive() {
    return object -> object.getClass().isPrimitive();
  }
}