You're essentially running out of memory to run the process smoothly. Options that come to mind:

1. Specify more memory like you mentioned, try something in between like -Xmx512m first
2. Work with smaller batches of HashMap objects to process at once if possible
3. If you have a lot of duplicate strings, use String.intern() on them before putting them into the HashMap
4. Use the HashMap(int initialCapacity, float loadFactor) constructor to tune for your case

You're essentially running out of memory to run the process smoothly. Options that come to mind:

1. Specify more memory like you mentioned, try something in between like -Xmx512m first
2. Work with smaller batches of HashMap objects to process at once if possible
3. If you have a lot of duplicate strings, use String.intern() on them before putting them into the HashMap
4. Use the HashMap(int initialCapacity, float loadFactor) constructor to tune for your case

You're essentially running out of memory to run the process smoothly. Options that come to mind:

1. Specify more memory like you mentioned, try something in between like -Xmx512m first
2. Work with smaller batches of HashMap objects to process at once if possible
3. If you have a lot of duplicate strings, use intern() on them before putting them into the HashMap
4. Use the HashMap(int initialCapacity, float loadFactor) constructor to tune for your case

You're essentially running out of memory to run the process smoothly. Options that come to mind:

1. Specify more memory like you mentioned, try something in between like -Xmx512m first
2. Work with smaller batches of HashMap objects to process at once if possible
3. If you have a lot of duplicate strings, use String.intern() on them before putting them into the HashMap
4. Use the HashMap(int initialCapacity, float loadFactor) constructor to tune for your case