サーブレットでmysqlからデータベースを所得
↓
dataListという名前の1つのarrayListに全ての値を入れる
↓
jspファイルに送ってそれを出力
ということをやりたいのですが
jspファイルでどのようにコードを書けばいいか分かりません。
コンソールではgetメソッドを使うことで思っている通りに出力することができました。
jspファイルへの渡し方、
jspファイル内でforEachを使う必要があると思うのですが
それの使い方がよく分かりません。
ご教示お願いします。
サーブレット
java
1 2 3import java.io.IOException; 4import java.sql.Connection; 5import java.sql.DriverManager; 6import java.sql.ResultSet; 7import java.sql.SQLException; 8import java.sql.Statement; 9import java.util.ArrayList; 10import java.util.HashMap; 11import java.util.List; 12import java.util.Map; 13 14import javax.servlet.RequestDispatcher; 15import javax.servlet.ServletException; 16import javax.servlet.annotation.WebServlet; 17import javax.servlet.http.HttpServlet; 18import javax.servlet.http.HttpServletRequest; 19import javax.servlet.http.HttpServletResponse; 20 21/** 22 * Servlet implementation class DataBaseServer 23 */ 24@WebServlet("/DataBaseServer") 25public class DataBaseServer extends HttpServlet { 26 private static final long serialVersionUID = 1L; 27 28 /** 29 * @see HttpServlet#HttpServlet() 30 */ 31 public DataBaseServer() { 32 super(); 33 // TODO Auto-generated constructor stub 34 } 35 36 /** 37 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) 38 */ 39 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 40 try { 41 Class.forName("com.mysql.jdbc.Driver"); 42 Connection conn = DriverManager.getConnection( 43 "jdbc:mysql://localhost:3306/record","root","xxxxxx"); 44 45 //データの出力 46 Statement st = conn.createStatement(); 47 ResultSet rs = 48 st.executeQuery("select * from first"); 49 50 List<DataClass> dataList = new ArrayList<DataClass>(); 51 52 53 54 while(rs.next()) { 55 DataClass data = new DataClass(); 56 57 58 data.setId(rs.getInt("id")); 59 data.setName(rs.getString("name")); 60 data.setJpn(rs.getInt("jpn")); 61 data.setMath(rs.getInt("math")); 62 data.setEng(rs.getInt("eng")); 63 data.setSci(rs.getInt("sci")); 64 65 dataList.add(data); 66 67 } 68 69 for(int i =0; i < dataList.size(); i++) { 70 System.out.println(dataList.get(i).getId() + dataList.get(i).getName() + dataList.get(i).getJpn() + dataList.get(i).getEng() + dataList.get(i).getMath() + dataList.get(i).getSci()); 71 } 72 73 request.setAttribute("1", dataList); 74 RequestDispatcher dispatcher = request.getRequestDispatcher("/Receiver.jsp"); 75 dispatcher.forward(request, response); 76 77 78 } catch (ClassNotFoundException e) { 79 System.out.println("ドライバを読み込めませんでした "+ e); 80 } catch (SQLException e) { 81 System.out.println("データベース接続エラー"+ e); 82 } 83 } 84 85 /** 86 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) 87 */ 88 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 89 // TODO Auto-generated method stub 90 doGet(request, response); 91 } 92 93} 94
jsp
pageEncoding="UTF-8"%> <%@ page import="javax.servlet.http.*,javax.servlet.*" %> <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> <%@ taglib prefix="sql" uri="http://java.sun.com/jsp/jstl/sql" %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body> <%=request.getAttribute("1") %> <c:forEach items="${1}" var="rows"> <c:out value="${rows.id}"/> <c:out value="${rows.name}"/> <c:out value="${rows.jpn}"/> <c:out value="${rows.math}"/> <c:out value="${rows.eng}"/> <c:out value="${rows.sci}"/> </c:forEach> </body> </html>
サーバーエラーが発生します。
error
1Type Exception Report 2 3Message An exception occurred processing [/Receiver.jsp] at line [14] 4 5Description The server encountered an unexpected condition that prevented it from fulfilling the request. 6 7Exception 8 9org.apache.jasper.JasperException: An exception occurred processing [/Receiver.jsp] at line [14] 10 1111: </head> 1212: <body> 1313: <%=request.getAttribute("1") %> 1414: <c:forEach items="${1}" var="rows"> 1515: <c:out value="${rows.id}"/> 1616: </c:forEach> 1717: <%-- 18 19 20Stacktrace: 21 org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:593) 22 org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:467) 23 org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:386) 24 org.apache.jasper.servlet.JspServlet.service(JspServlet.java:330) 25 javax.servlet.http.HttpServlet.service(HttpServlet.java:741) 26 org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) 27 DataBaseServer.doGet(DataBaseServer.java:119) 28 javax.servlet.http.HttpServlet.service(HttpServlet.java:634) 29 javax.servlet.http.HttpServlet.service(HttpServlet.java:741) 30 org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) 31 filter.SampleFilter.doFilter(SampleFilter.java:42) 32Root Cause 33 34javax.servlet.ServletException: javax.servlet.jsp.JspTagException: Don't know how to iterate over supplied "items" in <forEach> 35 org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:667) 36 org.apache.jsp.Receiver_jsp._jspService(Receiver_jsp.java:165) 37 org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) 38 javax.servlet.http.HttpServlet.service(HttpServlet.java:741) 39 org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:444) 40 org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:386) 41 org.apache.jasper.servlet.JspServlet.service(JspServlet.java:330) 42 javax.servlet.http.HttpServlet.service(HttpServlet.java:741) 43 org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) 44 DataBaseServer.doGet(DataBaseServer.java:119) 45 javax.servlet.http.HttpServlet.service(HttpServlet.java:634) 46 javax.servlet.http.HttpServlet.service(HttpServlet.java:741) 47 org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) 48 filter.SampleFilter.doFilter(SampleFilter.java:42) 49Root Cause 50 51javax.servlet.jsp.JspTagException: Don't know how to iterate over supplied "items" in <forEach> 52 org.apache.taglibs.standard.tag.common.core.ForEachSupport.toForEachIterator(ForEachSupport.java:312) 53 org.apache.taglibs.standard.tag.common.core.ForEachSupport.supportedTypeForEachIterator(ForEachSupport.java:276) 54 org.apache.taglibs.standard.tag.common.core.ForEachSupport.prepare(ForEachSupport.java:193) 55 javax.servlet.jsp.jstl.core.LoopTagSupport.doStartTag(LoopTagSupport.java:291) 56 org.apache.jsp.Receiver_jsp._jspx_meth_c_005fforEach_005f0(Receiver_jsp.java:189) 57 org.apache.jsp.Receiver_jsp._jspService(Receiver_jsp.java:147) 58 org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) 59 javax.servlet.http.HttpServlet.service(HttpServlet.java:741) 60 org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:444) 61 org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:386) 62 org.apache.jasper.servlet.JspServlet.service(JspServlet.java:330) 63 javax.servlet.http.HttpServlet.service(HttpServlet.java:741) 64 org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) 65 DataBaseServer.doGet(DataBaseServer.java:119) 66 javax.servlet.http.HttpServlet.service(HttpServlet.java:634) 67 javax.servlet.http.HttpServlet.service(HttpServlet.java:741) 68 org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) 69 filter.SampleFilter.doFilter(SampleFilter.java:42) 70Note The full stack trace of the root cause is available in the server logs.
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