我正在尝试使用JSTL显示数据库中的值，因为没有可重复使用的标记，所以我一直在使用另一个场景，根据我之前的问题，其他状态来限制<sql：query>，我开始使用servlet来转到表的查看页面，我无法使用该链接中的一维数组，因此我使用了ArrayList>。
<sql：query>
我的代码从数据库中获取值如下。
public ArrayList getAllStockDetails() { System.out.println("Function"); HashMap<String, String> stkMap = new HashMap<String, String>(); ArrayList<HashMap<String, String>> stkList= new ArrayList<>(); try { Dbconnection dcon = new Dbconnection(); dcon.connect(); String query = "Select * from tbstk"; Statement stmt = dcon.con.createStatement(); ResultSet rs = stmt.executeQuery(query); while (rs.next()) { //System.out.println(rs.getString("SCat_id") + rs.getString("SCat_des")); stkMap.put("idStk", rs.getString("Stk_prdid")); stkMap.put("prdStk", rs.getString("Stk_prdid")); stkMap.put("lvlStk", rs.getString("Stk_lvlid")); stkMap.put("inStk", rs.getString("Stk_instk")); stkMap.put("thldStk", rs.getString("Stk_thld")); stkMap.put("expStk", rs.getString("Stk_prdid")); stkList.add(stkMap); } return stkList; } catch (SQLException ex) { Logger.getLogger(Op_Stock.class.getName()).log(Level.SEVERE, null, ex); } return null; }
我的Servlet代码如下
protected void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String userPath = request.getServletPath(); switch (userPath) { case "/ViewStock": Op_Stock ops= new Op_Stock(); ArrayList<HashMap<String, String>> stkList= new ArrayList<>(); stkList=ops.getAllStockDetails(); request.setAttribute("stkList", stkList); userPath = "/Stock"; break; //Other cases } String url = "/WEB-INF/view" + userPath + ".jsp"; **request.getRequestDispatcher(url).forward(request, response);**//<--Error Here }
我页面中的代码如下
<table class="table table-bordered table-striped table-hover"> <thead> <th><strong>Product Name</strong></th> <th><strong>Level</strong></th> <th><strong>In Stock</strong></th> <th><strong>Threshold</strong></th> <th><strong>Expiry</strong></th> <th><strong>Operations</strong></th> </thead> <jsp:useBean id="gen" scope="request" class="Common.General"/> <jsp:useBean id="prd" scope="request" class="Product.Product"/> <tbody> <c:forEach var="row" items="${stkList.rows}"> <tr> <td><c:out value="${row.prdStk}"/></td> <td><c:out value="${row.lvlStk}"/></td> <td><c:out value="${row.inStk}"/></td> <td><c:out value="${row.thldStk}"/></td> <td><c:out value="${row.expStk}"/></td> <td> <button type="button" class="btn btn-default btn-sm btn-danger" onclick="deletedata('${row.idStk}');"> <span class="glyphicon glyphicon-trash"></span> </button> <button type="button" class="btn btn-default btn-sm btn-primary" onclick="editdata('${row.idStk}')"> <span class="glyphicon glyphicon-edit"></span> </button> <button class="btn btn-info btn-sm" data-toggle="modal" data-target="#myModal"> <span class="glyphicon glyphicon-eye-open"></span> </button> </td> </tr> </c:forEach> </tbody> <tfoot> <td></td> <td></td> <td></td> <td></td> <td></td> <td></td> </tfoot> </table>
我加载的页面仅返回空白页，我在此做错了什么，如果我做的代码错误，请更正我。
我的日志中的错误如下
Stacktrace:] with root cause java.lang.NumberFormatException: For input string: "rows" at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65) at java.lang.Integer.parseInt(Integer.java:580) at java.lang.Integer.parseInt(Integer.java:615) at javax.el.ListELResolver.coerce(ListELResolver.java:157) at javax.el.ListELResolver.getValue(ListELResolver.java:70) at org.apache.jasper.el.JasperELResolver.getValue(JasperELResolver.java:110) at org.apache.el.parser.AstValue.getValue(AstValue.java:167) at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:187) at org.apache.jasper.el.JspValueExpression.getValue(JspValueExpression.java:115) at org.apache.jsp.WEB_002dINF.view.Stock_jsp._jspx_meth_c_005fforEach_005f0(Stock_jsp.java:344) at org.apache.jsp.WEB_002dINF.view.Stock_jsp._jspService(Stock_jsp.java:191) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) at javax.servlet.http.HttpServlet.service(HttpServlet.java:725) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:405) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:349) at javax.servlet.http.HttpServlet.service(HttpServlet.java:725) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:721) at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:466) at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:391) at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:318) at Stock.Con_Stock.processRequest(Con_Stock.java:58) at Stock.Con_Stock.doGet(Con_Stock.java:74) at javax.servlet.http.HttpServlet.service(HttpServlet.java:618) at javax.servlet.http.HttpServlet.service(HttpServlet.java:725) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:503) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:136) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:526) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1078) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:655) at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:277) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2381) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2370) 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)
您需要更改的几件事：
默认情况下，ResultSet仅向前转发，因为您Stk_prdid多次访问列，所以它不返回任何值。
Stk_prdid
public ArrayList getAllStockDetails() { ... Statement stmt = dcon.con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY); .... while (rs.next()) { HashMap<String, String> stkMap = new HashMap<String, String>();//<-- move here stkList.add(stkMap); ... } .... }
在jsp中：
... <c:forEach var="row" items="${stkList}"> ... <td>${row.prdStk}</td> ... ...
