内存问题，请教大师如何优化

java.lang.OutOfMemoryError: Java heap space
com.mysql.jdbc.MysqlIO.unpackBinaryResultSetRow(MysqlIO.java:3259)
com.mysql.jdbc.MysqlIO.nextRow(MysqlIO.java:1291)
com.mysql.jdbc.MysqlIO.readSingleRowSet(MysqlIO.java:2214)
com.mysql.jdbc.MysqlIO.getResultSet(MysqlIO.java:433)
com.mysql.jdbc.MysqlIO.readResultsForQueryOrUpdate(MysqlIO.java:1922)
com.mysql.jdbc.MysqlIO.readAllResults(MysqlIO.java:1351)
com.mysql.jdbc.ServerPreparedStatement.serverExecute(ServerPreparedStatement.java:1185)
com.mysql.jdbc.ServerPreparedStatement.executeInternal(ServerPreparedStatement.java:684)
com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1049)
org.apache.tomcat.dbcp.dbcp.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:92)
org.apache.commons.dbutils.QueryRunner.query(QueryRunner.java:236)
org.apache.commons.dbutils.QueryRunner.query(QueryRunner.java:309)
org.apache.commons.dbutils.QueryRunner.query(QueryRunner.java:328)
com.handy.database.DBUtil.find(DBUtil.java:429)
com.handy.database.DBUtil.find(DBUtil.java:400)
com.handy.plugin.auth.dao.MobileUploadDao.findMobile(MobileUploadDao.java:71)
com.handy.plugin.auth.action.MobileUploadAction.readTxt(MobileUploadAction.java:164)
com.handy.plugin.auth.action.MobileUploadAction.execute(MobileUploadAction.java:43)
com.handy.webwork.action.InvokService.doAction(InvokService.java:276)
com.handy.webwork.action.InvokService.invok(InvokService.java:128)
com.handy.webwork.Dispatcher.invok(Dispatcher.java:46)
com.handy.webwork.FilterDispatcher.doFilter(FilterDispatcher.java:79)内存Java性能优化heap