我有一个简单的程序,它使用jconnect6对一个Sybase ASE DB执行查询。 程序迭代为603所的记录的结果集的while(rs.next())的NullPointerException
public ResultSet exec()
{
ResultSet rs = null;
try {
stmt= connection.createStatement();
rs = stmt.executeQuery(query);
} catch (SQLException ex) {
ex.printStackTrace();
}
try {
connection.close();
} catch (SQLException ex) {
ex.printStackTrace();
}
return rs;
}
public void Test()
{
ResultSet rs= exec();
if(rs!=null)
{
int i=0;
try {
while(rs!=null && rs.next()) { // NullPointerException here
System.out.println(i++);
}
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
的输出打印的值进行后抛出一个NullPointerException“I”直到其到达603而收集的记录是超过1000和下面是误差
May 13, 2014 11:43:43 AM appcomponents.OutageTest Test
SEVERE: null
java.lang.NullPointerException
at com.sybase.jdbc3.timedio.RawDbio.reallyRead(Unknown Source)
at com.sybase.jdbc3.timedio.Dbio.doRead(Unknown Source)
at com.sybase.jdbc3.timedio.InStreamMgr.a(Unknown Source)
at com.sybase.jdbc3.timedio.InStreamMgr.doRead(Unknown Source)
at com.sybase.jdbc3.tds.TdsProtocolContext.getChunk(Unknown Source)
at com.sybase.jdbc3.tds.PduInputFormatter.a(Unknown Source)
at com.sybase.jdbc3.tds.PduInputFormatter.read(Unknown Source)
at com.sybase.jdbc3.tds.TdsInputStream.read(Unknown Source)
at com.sybase.jdbc3.tds.TdsInputStream.readInt(Unknown Source)
at com.sybase.jdbc3.tds.TdsDataObject.readINTN(Unknown Source)
at com.sybase.jdbc3.tds.TdsInt.beginRead(Unknown Source)
at com.sybase.jdbc3.tds.TdsDataObject.doRead(Unknown Source)
at com.sybase.jdbc3.tds.TdsInt.getLong(Unknown Source)
at com.sybase.jdbc3.tds.CachedTdsInt.<init>(Unknown Source)
at com.sybase.jdbc3.tds.TdsInt.createCachedCopy(Unknown Source)
at com.sybase.jdbc3.tds.TdsResultSet.cacheCurrentRow(Unknown Source)
at com.sybase.jdbc3.tds.TdsResultSet.next(Unknown Source)
at com.sybase.jdbc3.jdbc.SybResultSet.next(Unknown Source)
at appcomponents.OutageTest.Test(OutageTest.java:143)
的ResultSet不事到处传递。确保连接也不是空的。我会建议你将这个resultSet合并到'void Test'方法中。 – ErrorNotFoundException
你知道在抛出npe时应该读哪些数据吗?你有这个hdbc驱动程序的源代码吗? – markusw
@Stanley,你是对的,它接近那些603记录是在我关闭连接之前收集到的,并且NPE由于这个错误而被抛出。 –