import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.JsonNode; String jsonStr = "{\"name\":\"John\",\"age\":30,\"city\":\"New York\"}"; ObjectMapper objectMapper = new ObjectMapper(); JsonNode jsonNode = objectMapper.readTree(jsonStr); String name = jsonNode.get("name").asText(); int age = jsonNode.get("age").asInt(); String city = jsonNode.get("city").asText(); ObjectMapper objectMapper = new ObjectMapper(); JsonNode jsonNode = objectMapper.createObjectNode(); ((ObjectNode) jsonNode).put("name", "John"); ((ObjectNode) jsonNode).put("age", 30); ((ObjectNode) jsonNode).put("city", "New York"); String jsonStr = objectMapper.writeValueAsString(jsonNode);