fastjson中JSONObject对象的getString()方法遇到的坑

比眉伴天荒 2023-01-20 14:50 25阅读 0赞

public class Test { 
       public static void main(String[] args) { 
            String str = "{\"context\":\"{\\\"flightNo\\\":\\\"ZH9112\\\",\\\"flightDate\\\":\\\"2021-06-30\\\",\\\"userId\\\":\\\"13706024\\\", \\\"tktNum\\\":\\\"54028714511230\\\",\\\"coupon\\\":\\\"1\\\", \\\"seatNum\\\":\\\"\\\",\\\"deptCode\\\":\\\"\\\", \\\"destCode\\\":\\\"SZX\\\", \\\"mobile\\\":\\\"18601246870\\\"}\"\n" +
                    "}";
            String objectStr = "{\"context\":{\"tktNum\":\"54028714511230\",\"flightNo\":\"ZH9112\",\"seatNum\":\"\",\"flightDate\":\"2021-06-30\",\"coupon\":\"1\",\"destCode\":\"SZX\",\"mobile\":\"18601246870\",\"userId\":\"13706024\",\"deptCode\":\"\"}}";
            
            JSONObject strJSON = JSONObject.parseObject(str, JSONObject.class);
            JSONObject objectJSON = JSONObject.parseObject(objectStr, JSONObject.class);
    
            System.out.println("111: " + strJSON.getString("context"));
            System.out.println("222: " + objectJSON.getString("context"));
            System.out.println("====================================================================================================================");
            System.out.println("333: " + JSONObject.toJSONString(strJSON.get("context")));
            System.out.println("444: " + JSONObject.toJSONString(objectJSON.get("context")));
        }
    }

执行结果：

111: { "flightNo":"ZH9112","flightDate":"2021-06-30","userId":"13706024", "tktNum":"54028714511230","coupon":"1", "seatNum":"","deptCode":"", "destCode":"SZX", "mobile":"18601246870"}
    222: { "tktNum":"54028714511230","flightNo":"ZH9112","seatNum":"","flightDate":"2021-06-30","coupon":"1","destCode":"SZX","mobile":"18601246870","userId":"13706024","deptCode":""}
    ====================================================================================================================
    333: "{\"flightNo\":\"ZH9112\",\"flightDate\":\"2021-06-30\",\"userId\":\"13706024\", \"tktNum\":\"54028714511230\",\"coupon\":\"1\", \"seatNum\":\"\",\"deptCode\":\"\", \"destCode\":\"SZX\", \"mobile\":\"18601246870\"}"
    444: { "tktNum":"54028714511230","flightNo":"ZH9112","seatNum":"","flightDate":"2021-06-30","coupon":"1","destCode":"SZX","mobile":"18601246870","userId":"13706024","deptCode":""}

看了上面的代码，大家一定会觉得很简单的代码，有什么问题呢？现在由我来揭穿它坑爹的面纱！！

**str字符串**转换成json格式：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM0MjQxODYx_size_16_color_FFFFFF_t_70]

**objectStr字符串**转换成json格式：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM0MjQxODYx_size_16_color_FFFFFF_t_70 1]  
虽然这两个字符串看起来很像，但是实际上当两者转换成json格式后，可以清晰地看出前者context这个key对应的值类型是**String类型**，后者context这个key对应的值类型是**对象类型**。

针对上述两个字符串，使用JSONObject提供的 **getString()** 将context这个key对应的值以String类型提取出来时，惊奇地发现**结果的格式、包含的字段都是一样的，并不能看出来原始数据之间的差别**。如果是需要根据value类型不同做不同处理的情况，那这种方式是无法达到目的

接下来，我尝试着使用 **JSONObject.toJSONString()** 方法来做这件事，发现得到的结果和我的预期是一样的，**能够显而易见地判断出原始数据的类型**。

这两种方式获取String串的不同之处，我也看了看源码，但是不太明白，所以到此结束～

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