我有一段java程序，是每日定时跑的。偶尔会出现如题的报错。一般情况下是半个月报一两次。很诡异，求大神解答，代码如下：

public class MainJobPre extends BaseData implements Job{

private Logger log = Logger.getLogger(MainJobPre.class);

public void execute(JobExecutionContext jobexecutioncontext)

throws JobExecutionException {

Connection conn = null;

PreparedStatement ps = null;

ResultSet rs = null;

PreparedStatement query = null;

ResultSet queryresult = null;

PreparedStatement delete = null;

PreparedStatement insert = null;

PreparedStatement query2 = null;

PreparedStatement insert2 = null;

PreparedStatement delete2 = null;

ResultSet queryresult2 = null;

log.info("===================start copy timer job===================");

try{

Class.forName("oracle.jdbc.driver.OracleDriver");

conn = DriverManager.getConnection(getUrl(), getUsername(), getPassword());

conn.setAutoCommit(false);//取消自动提交

query = conn.prepareStatement("select JOB_ID,PRODUCT_NAME,DBA_NAME,PRODUCT_MAIL,DBA_MAIL,JOB_STARTTIME,JOB_COMPLETETIME,WEEK_DAY,MONTH_DATE,QUARTER_MONTH,YEAR_MONTH,PERIOD,SQL,JOB_NAME,LOGIN_NAME,PRODUCT_PHONE,DBA_PHONE,IS_SHELL,SFILE_NAME from KF_TIMER_JOB");

queryresult = query.executeQuery();

delete = conn.prepareStatement("delete KF_TIMER_JOB_TMP");

delete.execute();

while(queryresult.next()){

String string13 = toString(queryresult.getObject(13));

string13 = string13.replace("'", "''");

insert = conn.prepareStatement("insert into KF_TIMER_JOB_TMP(JOB_ID,PRODUCT_NAME,DBA_NAME,PRODUCT_MAIL,DBA_MAIL,JOB_STARTTIME,JOB_COMPLETETIME,WEEK_DAY,MONTH_DATE,QUARTER_MONTH,YEAR_MONTH,PERIOD,SQL,JOB_NAME,LOGIN_NAME,PRODUCT_PHONE,DBA_PHONE,IS_SHELL,SFILE_NAME) values('"+toString(queryresult.getObject(1))+"','"+toString(queryresult.getObject(2))+"','"+toString(queryresult.getObject(3))+"','"+toString(queryresult.getObject(4))+"','"+toString(queryresult.getObject(5))+"','"+toString(queryresult.getObject(6))+"','"+toString(queryresult.getObject(7))+"','"+toString(queryresult.getObject(8))+"','"+toString(queryresult.getObject(9))+"','"+toString(queryresult.getObject(10))+"','"+toString(queryresult.getObject(11))+"','"+toString(queryresult.getObject(12))+"','"+string13+"','"+toString(queryresult.getObject(14))+"','"+toString(queryresult.getObject(15))+"','"+toString(queryresult.getObject(16))+"','"+toString(queryresult.getObject(17))+"','"+toString(queryresult.getObject(18))+"','"+toString(queryresult.getObject(19))+"')");

insert.execute();

}

query2 = conn.prepareStatement("select JOB_ID,JOB_REFER_ID from KF_TIMER_JOB_REFER");

queryresult2 = query2.executeQuery();

delete2 = conn.prepareStatement("delete KF_TIMER_JOB_REFER_TMP");

delete2.execute();

while(queryresult2.next()){

log.info("1"+String.valueOf(queryresult2.getObject(1)));

log.info("2"+String.valueOf(queryresult2.getObject(2)));

insert2 = conn.prepareStatement("insert into KF_TIMER_JOB_REFER_TMP(JOB_ID,JOB_REFER_ID) values ('"+toString(queryresult2.getObject(1))+"','"+toString(queryresult2.getObject(2))+"')");

insert2.execute();

}

conn.commit();

}catch(Exception e){

e.printStackTrace();

try {

conn.rollback();

} catch (SQLException e1) {

// TODO Auto-generated catch block

e1.printStackTrace();

}

log.info("===================start copy timer job failed==================="+e.getMessage());

}finally{

try {

if(queryresult!=null){

queryresult.close();

}

if(queryresult2!=null){

queryresult2.close();

}

if(delete!=null){

delete.close();

}

if(query!=null){

query.close();

}

if(insert!=null){

insert.close();

}

if(delete2!=null){

delete2.close();

}

if(query2!=null){

query2.close();

}

if(insert2!=null){

insert2.close();

}

if(conn!=null){

conn.close();

}

} catch (Exception e2) {

e2.printStackTrace();

}

}

具体报错信息如下：

java.sql.SQLException: Socket read timed out

at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:412)

at oracle.jdbc.driver.PhysicalConnection.(PhysicalConnection.java:531)

at oracle.jdbc.driver.T4CConnection.(T4CConnection.java:221)

at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:32)

at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:503)

at java.sql.DriverManager.getConnection(DriverManager.java:571)

at java.sql.DriverManager.getConnection(DriverManager.java:215)

at com.netease.market.job.MainJobPre.execute(Unknown Source)

at org.quartz.core.JobRunShell.run(JobRunShell.java:216)

at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:549)

Caused by: oracle.net.ns.NetException: Socket read timed out

at oracle.net.ns.Packet.receive(Packet.java:320)

at oracle.net.ns.NSProtocol.connect(NSProtocol.java:286)

at oracle.jdbc.driver.T4CConnection.connect(T4CConnection.java:1042)

at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:301)

... 9 more

2014年5月08日 14:15