google safebrowsing api java client is giving: java.io.IOException: insufficient data written

When i'm using the google safebrowsing api through the google java client for the same( https://developers.google.com/resources/api-libraries/documentation/safebrowsing/v4/java/latest/ ) it is working fine when I'm trying to make one api request at a time.

Now, i'm trying to make simultaneous requests for full hashes using the java ExecutorService threadpool, i'm getting the following error :

  java 
 . 
 io 
 . 
 IOException 
 : 
 insufficient data written
 at sun 
 . 
 net 
 . 
 www 
 . 
 protocol 
 . 
 http 
 . 
 HttpURLConnection$StreamingOutputStream 
 . 
 close 
 ( 
 HttpURLConnection 
 . 
 java 
 : 
 3501 
 ) 
 at com 
 . 
 google 
 . 
 api 
 . 
 client 
 . 
 http 
 . 
 javanet 
 . 
 NetHttpRequest 
 . 
 execute 
 ( 
 NetHttpRequest 
 . 
 java 
 : 
 81 
 ) 
 at com 
 . 
 google 
 . 
 api 
 . 
 client 
 . 
 http 
 . 
 HttpRequest 
 . 
 execute 
 ( 
 HttpRequest 
 . 
 java 
 : 
 981 
 ) 
 at com 
 . 
 google 
 . 
 api 
 . 
 client 
 . 
 googleapis 
 . 
 services 
 . 
 AbstractGoogleClientRequest 
 . 
 executeUnparsed 
 ( 
 AbstractGoogleClientRequest 
 . 
 java 
 : 
 419 
 ) 
 at com 
 . 
 google 
 . 
 api 
 . 
 client 
 . 
 googleapis 
 . 
 services 
 . 
 AbstractGoogleClientRequest 
 . 
 executeUnparsed 
 ( 
 AbstractGoogleClientRequest 
 . 
 java 
 : 
 352 
 ) 
 at com 
 . 
 google 
 . 
 api 
 . 
 client 
 . 
 googleapis 
 . 
 services 
 . 
 AbstractGoogleClientRequest 
 . 
 execute 
 ( 
 AbstractGoogleClientRequest 
 . 
 java 
 : 
 469 
 ) 
 at net 
 . 
 media 
 . 
 safeBrowsing 
 . 
 request 
 . 
 FindFullHashesApiRequest 
 . 
 makeRequest 
 ( 
 FindFullHashesApiRequest 
 . 
 java 
 : 
 35 
 ) 
 at net 
 . 
 media 
 . 
 safeBrowsing 
 . 
 util 
 . 
 FindFullHashesCallable 
 . 
 retryRequest 
 ( 
 FindFullHashesCallable 
 . 
 java 
 : 
 35 
 ) 
 at net 
 . 
 media 
 . 
 safeBrowsing 
 . 
 util 
 . 
 FindFullHashesCallable 
 . 
 call 
 ( 
 FindFullHashesCallable 
 . 
 java 
 : 
 29 
 ) 
 at java 
 . 
 util 
 . 
 concurrent 
 . 
 FutureTask 
 . 
 run 
 ( 
 FutureTask 
 . 
 java 
 : 
 266 
 ) 
 

I'm adding around 5000 prefixes in each findFullHashes request in both cases(single request at a time and multithreading). Can anyone please point out my mistake?