session沒有為空，但是我貼源碼上來看嘛
public class messageDao {
//private String url = "jdbc:oracle:thin:@localhost:1521:orcl"; // URL地址
public List<Message> queryMessageList(String command, String description) {
DBaccess dbaccess = new DBaccess();
List<Message> messageList = new ArrayList<Message>();
SqlSession sqlsession = null;
try {
sqlsession = dbaccess.getSqlSession();
// 通過SqlSession 對象去執(zhí)行sql語句
messageList = sqlsession.selectList("Message.queryMessageList");
} catch (IOException e) {
e.printStackTrace();
} finally {
if (sqlsession != null) {
System.out.println("連接成功,準(zhǔn)備關(guān)閉！2");
sqlsession.close();
} else {
System.out.println("失敗222！");
}
}
return messageList;
}
2018-04-02
好嘛，謝謝你的回答
2018-04-01
抱歉，我也不知道怎樣解決
2018-04-01
控制臺輸出的錯誤信息是
連接成功,準(zhǔn)備關(guān)閉！1
連接成功,準(zhǔn)備關(guān)閉！2
四月 01, 2018 9:46:26 下午 org.apache.catalina.core.StandardWrapperValve invoke
嚴(yán)重: Servlet.service() for servlet [ListServlet] in context with path [/MicroMessage] threw exception [Servlet execution threw an exception] with root cause
java.lang.AbstractMethodError: Method oracle/jdbc/driver/T4CPreparedStatement.isClosed()Z is abstract
at oracle.jdbc.driver.T4CPreparedStatement.isClosed(T4CPreparedStatement.java)
at org.apache.ibatis.executor.BaseExecutor.closeStatement(BaseExecutor.java:285)
at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:65)
at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:326)
at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156)
at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:109)
at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:83)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:148)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:141)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:136)
at been.messageDao.queryMessageList(messageDao.java:30)
at service.ListService.queryMessageList(ListService.java:16)
at servlet.ListServlet.doGet(ListServlet.java:46)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:110)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:506)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:962)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:445)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1115)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2555)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2544)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)
2018-04-01
頁面提示的錯誤是500
type?Exception report
message?Servlet execution threw an exception
description?The server encountered an internal error that prevented it from fulfilling this request.
exception
root cause
note?The full stack trace of the root cause is available in the Apache Tomcat/7.0.82 logs.