getLong和getString获取的值不同

Question

代码如下：

 JSONObject contentObject = new JSONObject(content);
 JSONObject params = contentObject.getJSONObject("response_params");
 Log.d("onTest", "channel_id:" + params.getString("channel_id"));
 Log.d("onTest", "channel_id:" + params.getLong("channel_id"));

日志打印：

  08-21 12:46:21.470: DEBUG/onTest(25228): onMessage: content : {"response_params":{"appid":"1071410","channel_id":"3537275240990320342","user_id":"714893193627619861"},"request_id":1293438498}
   08-21 12:46:21.480: DEBUG/onTest(25228): channel_id:3537275240990320342
   08-21 12:46:21.480: DEBUG/onTest(25228): channel_id:3537275240990320128

为什么getLong 值是3537275240990320128
而String 值是3537275240990320342

Answer 1

说明文档里是这样写的：

public long getLong (String name)

Returns the value mapped by name if it exists and is a long or can be coerced to a long. Note that JSON represents numbers as doubles, so this is lossy; use strings to transfer numbers via JSON.