java连接Oracle数据库问题

Question

五月 23, 2016 11:09:27 上午 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet [HANA.HanaInputOracle] in context with path [/JAVA_HANA] threw exception
java.lang.NullPointerException
    at HANA.HanaInputOracle.doPost(HanaInputOracle.java:59)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
    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:220)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:957)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:620)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
    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:745)
这是报错信息，以下是相对应的java文件

package HANA;

import java.io.IOException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**

• Servlet implementation class HanaInputOracle
  */

@WebServlet("/HanaInputOracle")
public class HanaInputOracle extends HttpServlet {

private static final long serialVersionUID = 1L;

/**

• @see HttpServlet#HttpServlet()
  */

1. HanaInputOracle() {

      super();
      // TODO Auto-generated constructor stub

   }

   /**

   • @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse

   • response)
     */

2. void doGet(HttpServletRequest request, HttpServletResponse response)

          throws ServletException, IOException {
      // TODO Auto-generated method stub

   }

   /**

   • @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse

   • response)
     */

3. void doPost(HttpServletRequest request, HttpServletResponse response)

          throws ServletException, IOException {
      // TODO Auto-generated method stub
   
      ORACLE oarcle = new ORACLE();
      Connection conn = oarcle.connoracle();
      PreparedStatement st = null;
   
      USER user = (USER) request.getSession().getAttribute("zb");
   
      String INSERT = "insert into SCM_S901 VALUES('" + user.getSPMON() + "','" + user.getSPTAG() + "','"

4. • user.getVTWEG() + "','" + user.getMATNR() + "','" + user.getZXSJE() + "')";

       //String SEC = "select * from SAPRED.S901 where SPMON='201506'";
     

1. {

         // st.executeUpdate(SEC);
         st.executeUpdate(INSERT);
   
         response.sendRedirect("../result.jsp");
     } catch (SQLException e) {
         // TODO Auto-generated catch block
         e.printStackTrace();
         response.sendRedirect("../error.jsp");
     }

   }

}

Answer 1

HanaInputOracle.java

doPost方法发出来给大家看看。

Answer 2

USER user = (USER) request.getSession().getAttribute("zb");
这里没判null吧，所以下面insert语句里面取值空指针了，debug user，看是不是null

Answer 3

 PreparedStatement st = null;
 这样就完事了？声明了不需要通过connection得到它吗？
 还是代码没贴全？

Answer 4

@MaxValue 你好，我的st是得到了值的啊，如下图