Connection conn= DbUtil.getConnection();
Statement stmt=null;
System.out.println(conn+"&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&");
stmt=conn.createStatement();
System.out.println(conn+"!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!");
ResultSet rs = stmt.executeQuery("select * from exam order by exam_id");
显示为:
com.microsoft.jdbc.sqlserver.SQLServerConnection@161dfb5&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
java.sql.SQLException: [Microsoft][SQLServer 2000 Driver for JDBC]Object has been closed.
at com.microsoft.jdbc.base.BaseExceptions.createException(Unknown Source)
at com.microsoft.jdbc.base.BaseExceptions.getException(Unknown Source)
at com.microsoft.jdbc.base.BaseConnection.validateClosedState(Unknown Source)
at com.microsoft.jdbc.base.BaseConnection.createStatement(Unknown Source)
at com.microsoft.jdbc.base.BaseConnection.createStatement(Unknown Source)
at com.sdjzglxy.jwMis.dao.ExamDaoImpl.queryExams(ExamDaoImpl.java:87)
at com.sdjzglxy.jwMis.jwMisFrame.JwMisFrame.createQueryPanel(JwMisFrame.java:421)
at com.sdjzglxy.jwMis.jwMisFrame.JwMisFrame.(JwMisFrame.java:96)
at com.sdjzglxy.jwMis.jwMisFrame.JwMisFrame.main(JwMisFrame.java:719)
我觉得问题是这段代码:stmt=conn.createStatement();
因为我打印了conn它并不为null,但是执行stmt=conn.createStatement();却提示数据库已经关闭。我想问一下,究竟该如何解决。