com.github.naviit.libs.common.util.JsonUtil Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of dtt-common Show documentation

The collections of utility classes is used regularly

There is a newer version: 1.0.3

/************************************************
 * Copyright 2017 by DTT - All rights reserved. *    
 ************************************************/
package com.github.naviit.libs.common.util;

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.function.Function;
import java.util.function.Predicate;

import com.fasterxml.jackson.annotation.JsonInclude.Include;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;

/**
 * @author  Dang Thanh Tung 
 * {@literal }
 * @since   28/12/2017
 */
public class JsonUtil {

  private static final ObjectMapper MAPPER;

  static {
    MAPPER = new ObjectMapper();
    MAPPER.setSerializationInclusion(Include.NON_NULL);
  }

  public static  String toJson(O o) {
    try {
      return MAPPER.writeValueAsString(o);
    } catch (Exception e) {
      return e.getMessage();
    }
  }

  public static  T toObject(String jsonStr, final Class clazz) {
    try {
      return MAPPER.readValue(jsonStr, clazz);
    } catch (Exception e) {
      return null;
    }
  }

  public static  T toObject(String jsonStr, final TypeReference reference) {
    try {
      return MAPPER.readValue(jsonStr, reference);
    } catch (Exception e) {
      return null;
    }
  }

  public static  Predicate distinctByKey(Function keyExtractor) {
    Map map = new ConcurrentHashMap<>();
    return t -> map.putIfAbsent(keyExtractor.apply(t), Boolean.TRUE) == null;
  }

}