1.getString(Stringname)与optStringname)，功能一样，只是当无返回值时，name)抛出错误，name)返回空值
getString(Stringname)
Returns the value mapped bynameif it exists,coercing it if necessary,or throws if no such mapping exists.
name
optString(Stringname)
原文链接：https://www.f2er.com/json/289260.html
