Packet for query is too large (1550606 > 1048576). You can change this value on the server by setting the max_allowed_  packet' variable.          at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3915)          at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2598)          at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2778)          at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2825)          at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2156)          at com.mysql.jdbc.PreparedStatement.execute(PreparedStatement.java:1379)          at com.hq.sql.Mysql.insert(Mysql.java:152)          at com.hq.sql.SqlExcution.query2Insert(SqlExcution.java:90)          at com.hq.schedule.Schedule.main(Schedule.java:27)      ---------------------------------------------------------------------------------------------------------------------    产生的主要原因就是，查询返回的数据量比较大，而允许返回的”max_allowed_packet”太小，导致以上错误。    在linux系统下，找到/etc/my.cnf文件，修改max_allowed_packet=50M，重启mysql服务