Getting String from Google- Books-Api when String isn't present in all Array element [duplicate]

Getting String from Google- Books-Api when String isn't present in all Array element [duplicate]



This question already has an answer here:



I am using the google books api (https://www.googleapis.com/books/v1/volumes) to query for books. I encountered an issue when trying to get the JSONObject of certain fields: eg. some values does not have a "subtitle" String in the "volumeInfo" JSONObject. This is a part of a result for 2 books



"kind": "books#volume",
"id": "XMrZrA1vomQC",
"etag": "54+ok3hELTA",
"selfLink": "https://www.googleapis.com/books/v1/volumes/XMrZrA1vomQC",
"volumeInfo":
"title": "Shakespeare",
"subtitle": "For All Time",
"authors": [
"Stanley W. Wells"
],
"publisher": "Oxford University Press on Demand",
"publishedDate": "2003-01"

,




"kind": "books#volume",
"id": "LpZRnseuZHIC",
"etag": "QxfQuF7p2Mg",
"selfLink": "https://www.googleapis.com/books/v1/volumes/LpZRnseuZHIC",
"volumeInfo":
"title": "Shakespeare, Contemporary Critical Approaches",
"authors": [
"Harry Raphael Garvin",
"Michael Payne"
],
"publisher": "Bucknell University Press",
"publishedDate": "1980"




How do I get the String for "subtitle" without encountering an error when it doesn't exist. I'm using this


String subTitle = volumeInfoObject.getString("subtitle");



but then, when it iterates to a set that doesn't have "subtitle" i receive this error in my logcat and my UI is not updated with the result


W/System.err: org.json.JSONException: No value for subtitle



How do I handle this exception? Thanks a lot



This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.





You could check if they key exists first using has(), before trying to get its value. Alternatively, you could use optString() instead of getString(), as it won't throw an Exception. Examples of both are shown in the linked duplicate.
– Mike M.
2 days ago



has()


optString()


getString()




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