java - Large list returned from a SimpleJdbcTemplate query -



java - Large list returned from a SimpleJdbcTemplate query -

here problem : @ point in java program, (very) big list of events database using simplejdbctemplate class spring.

list<event> events = this.simplejdbctemplate.query(myquery, mymapper(), new object[] { filter.getfirst(), filter.getsecond(), filter.getthird()} );

the problem list may contain 600,000 events ... hence using lot of memory (and taking time processed).

however don't need retrieve events @ once. able iterate on list, read few events (linked specific key_id - sql query myquery ordered key_id), process them , iterating, letting garbage collector rid of previous , processed events never exceed amount of memory.

is there nice way using spring library (or library)?

cheers, vakimshaar.

if understand correctly, iterate on result set, not interested in building total list of results.

just utilize query method resultsetextractor argument. resultsetextractor can utilize mapper transform current row event. set every event list until reach different key_id or end of result set, proceed list of events , clear list.

java sql spring jdbc spring-jdbc

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