JSON字符串转换为JsonNode

1.概述

使用Jackson 2将JSON字符串转换为JsonNode（com.fasterxml.jackson.databind.JsonNode）。

2.快速解析

解析JSON字符串，只需要一个ObjectMapper：

String jsonString = "{\"k1\":\"v1\",\"k2\":\"v2\"}";

ObjectMapper mapper = new ObjectMapper();
JsonNode actualObj = mapper.readTree(jsonString);
System.out.println(actualObj);

3.低层解析

String jsonString = "{\"k1\":\"v1\",\"k2\":\"v2\"}";
ObjectMapper mapper = new ObjectMapper();
JsonFactory factory = mapper.getFactory();
JsonParser parser = factory.createParser(jsonString);
JsonNode actualObj = mapper.readTree(parser);
System.out.println(actualObj);

4.使用JsonNode

String jsonString = "{\"k1\":\"v1\",\"k2\":\"v2\"}";
ObjectMapper mapper = new ObjectMapper();
JsonNode actualObj = mapper.readTree(jsonString);
// When
JsonNode jsonNode1 = actualObj.get("k1");
System.out.println(jsonNode1.asText().equals("v1"));