CODEWITHSUNDEEP
javajsonparsinglong-integer
ERJAN
ERJAN

Reputation: 24500

number of type 'long' changes its value when printed in java

I parse JSON data and there is book id , it is a big number:

"Books":[{"ID":88401542,"Title":"Building and Testing with Gradle","SubTitle":"Understanding Next-Generation Builds","Description":"Build and test software written in Java and many other languages with Gradle, the open source project automation tool that's getting a lot of attention. This concise introduction provides numerous code examples to help you explore Gradle, both as a b ..."},{"ID":2676913857...}

long book_id = 0 ;
try {
book_id = jsonBook.getInt(BOOK_ID);
Log.v(LOG_TAG, "book id: " + );

it prints me some stupid negative number:

book id: -1814548740

what is the reason? can it be because I print it without casting? my log statement should be:

Log.v("book id: " + new Long (book_id)) ;

or

Log.v("book id: " + new Long (book_id.toString())) ;

or

Log.v("book id: " + new String ( new Long(book_id))) ;

Upvotes: 0

Views: 107

Answers (4)

Jens
Jens

Reputation: 69460

Since your Book_ID is an Long you should use getLong to get the value:

book_id = jsonBook.getLong(BOOK_ID);

Upvotes: 1

yiabiten
yiabiten

Reputation: 810

You use getInt() to read a long. If the long value you're trying to read is large than an int then what you get is normal.

Upvotes: 1

NoDataFound
NoDataFound

Reputation: 11969

I think your problem lies in that:

book_id = jsonBook.getInt(BOOK_ID);

If getInt(BOOK_ID) returns a number that overflow the int type, then you should not expect it to work correctly. (I guessed int because of the method name).

You can either check for your JSON API if it has a getLong method, either store as string, and use Long.valueOf, Long.parseLong and so on...

Upvotes: 1

Konstantin Yovkov
Konstantin Yovkov

Reputation: 62864

Probably this value exceeds the Integer.MAX_VALUE. Better use BigInteger:

BigInteger book_id = BigInteger(jsonBook.getText(BOOK_ID));

I'm not sure if getText() is correct, but the idea is to fetch the value as a String.

Upvotes: 1

Related Questions