optstring不转换为字符串[aws json对象]

Question

I am using com.amazonaws.util.json.JSONObject

In the documentation it says

public String optString(String key)

Get an optional string associated with a key. It returns an empty string if there is no such key. If the value is not a string and is not null, then it is coverted to a string.

Parameters: key - A key string. Returns: A string which is the value.

I have a json object like {"time":1505900658464} and when i use optstring i expect it to convert this long value to string ,but it actually returns " " (instead of converted long values as string).Am i missing something?

Answer 1

First, the optString() method is supposed to return empty string: "" if there is no available String value. See the Documentation.

Second, the object {"time":1505900658464} has long value not string. You should use optLong instead. See the Documentation .

Also, you might need to read this discussion , and for converting time from Unix (that's the format you provided in your example) to simpleDateFormat see this.