JSON中getString() 和optString()

The difference is that optString returns the empty string ("") if the key you specify doesn't exist.getString on the other hand throws a JSONException. Use getString if it's an error for the data to be missing, or optString if you're not sure if it will be there.

这个是在stackoverflow上面看到的，mark一下，简单来说就是optString会在得不到你想要的值时候返回空字符串”“，而getString会抛出异常。