Java 使用MYSQL的JSP中的NoSuchElementException

Java 使用MYSQL的JSP中的NoSuchElementException,java,mysql,jsp,Java,Mysql,Jsp,我不断得到以下异常:org.apache.jasper.JasperException:java.util.NoSuchElementException 你能帮我写代码吗,因为我明显遗漏了什么。非常感谢 JSP文件: <% Enumeration names = request.getParameterNames(); while (names.hasMoreElements()) { String name = (String) names.nextElement()

我不断得到以下异常:org.apache.jasper.JasperException:java.util.NoSuchElementException

你能帮我写代码吗,因为我明显遗漏了什么。非常感谢

JSP文件:

    <%
  Enumeration names = request.getParameterNames();
  while (names.hasMoreElements()) {
  String name = (String) names.nextElement();
  StringBuffer sb = new StringBuffer(name);
  sb.deleteCharAt(0);
  VoCo.Vogel.Delete(sb.toString());
}

%>
<br>

<div class="navigator">
<a href="index.jsp">Add</a>
<a id="currenttab" href="waarnemingen.jsp">Delete</a>
</div>

<br> <br> <br>

<form action="waarnemingen.jsp" method="post">
<table>
<tr>
<th>Datum</th>
<th>Tijd</th>
<th>Plaats</th>
<th>Spotternaam</th>
<th>Vogelsoort</th>
</tr> 
<%

List list = VoCo.Vogel.GetWaarnemingen();
int id = 0;
String box = null;

Iterator<String> it = list.iterator();

while (it.hasNext()) {
  id = Integer.parseInt(it.next());
  out.print("<tr>");
  for (int i = 0; i < 5; i++) {
      out.print("<td>");
      out.print(it.next());
      out.print("</td>");
}
out.print("<td>");
box = "<input name=r" + id + " type='checkbox'>";
out.print(box);
out.print("</td>");
out.print("</tr>");
}
%>

</table>

<br>
<input type="submit" value="Delete">

</form>





资料 蒂吉德 普拉茨 斯波特纳姆 沃格尔肖特
java文件:

    public class Vogel {
static final String url = "jdbc:mysql://localhost:3306/turving";

public static void Insert(String datum, String tijd, String plaats, String spotternaam, String vogelsoort) {
  try {

      String insert = "INSERT INTO turving(datum, tijd, plaats, spotternaam, vogelsoort)" + "VALUES (?, ?, ?, ?, ?)";

      Class.forName("com.mysql.jdbc.Driver");
      Connection con = DriverManager.getConnection(url, "root", "");

      PreparedStatement ps = con.prepareStatement(insert);

      ps.setString(1, datum);
      ps.setString(2, tijd);
      ps.setString(3, plaats);
      ps.setString(4, spotternaam);
      ps.setString(5, vogelsoort);
      ps.executeUpdate();
      con.close();

  } catch (Exception ex) {
      Logger.getLogger(Vogel.class.getName()).log(Level.SEVERE, null, ex);
  }
 }

 public static List GetWaarnemingen() {

  List<String> list = new ArrayList<String>();

  try {

      Class.forName("com.mysql.jdbc.Driver");
      Connection con = DriverManager.getConnection(url, "root", "");

      Statement stmt = con.createStatement();

      ResultSet result = stmt.executeQuery("SELECT * FROM turving");

      while(result.next())
      {
         list.add(result.getString("id"));
         list.add(result.getString("datum"));
         list.add(result.getString("tijd"));
         list.add(result.getString("plaats"));
         list.add(result.getString("spotternaam"));
         list.add(result.getString("vogelsoort"));
      } 

      con.close();

  } catch (Exception ex) {
      Logger.getLogger(Vogel.class.getName()).log(Level.SEVERE, null, ex);
  }
      return list;
  }

 public static void Delete(String id) {
  try {
      String delete = "DELETE from turving WHERE id = ?";

      Class.forName("com.mysql.jdbc.Driver");
      Connection con = DriverManager.getConnection(url, "root", "");
      PreparedStatement ps = con.prepareStatement(delete);

      ps.setString(1, id);
      ps.executeUpdate();
      con.close();

  } catch (Exception ex) {
      Logger.getLogger(Vogel.class.getName()).log(Level.SEVERE, null, ex);
  }
 }
}
public-class-Vogel{
静态最终字符串url=“jdbc:mysql://localhost:3306/turving";
公共静态空白插入(字符串基准、字符串tijd、字符串plaats、字符串spotternaam、字符串vogelsoort){
试一试{
字符串insert=“插入旋转(基准面、tijd、plaats、spotternaam、vogelsoort)”+“值(?,,?,?,?)”;
Class.forName(“com.mysql.jdbc.Driver”);
Connection con=DriverManager.getConnection(url,“根目录”,“根目录”);
编制的报表ps=合同编制报表(插入);
ps.setString(1,基准);
ps.setString(2,tijd);
ps.setString(3,plaats);
ps.setString(4,spotternaam);
ps.setString(5名,vogelsoort);
ps.executeUpdate();
con.close();
}捕获(例外情况除外){
Logger.getLogger(Vogel.class.getName()).log(Level.SEVERE,null,ex);
}
}
公共静态列表GetWaarnemingen(){
列表=新的ArrayList();
试一试{
Class.forName(“com.mysql.jdbc.Driver”);
Connection con=DriverManager.getConnection(url,“根目录”,“根目录”);
语句stmt=con.createStatement();
ResultSet result=stmt.executeQuery(“从turving中选择*);
while(result.next())
{
添加(result.getString(“id”);
添加(result.getString(“数据”);
添加(result.getString(“tijd”);
list.add(result.getString(“plaats”);
添加(result.getString(“spotternaam”);
添加(result.getString(“vogelsoort”);
} 
con.close();
}捕获(例外情况除外){
Logger.getLogger(Vogel.class.getName()).log(Level.SEVERE,null,ex);
}
退货清单;
}
公共静态无效删除(字符串id){
试一试{
String delete=“从turving中删除,其中id=?”;
Class.forName(“com.mysql.jdbc.Driver”);
Connection con=DriverManager.getConnection(url,“根目录”,“根目录”);
PreparedStatement ps=con.prepareStatement(删除);
ps.setString(1,id);
ps.executeUpdate();
con.close();
}捕获(例外情况除外){
Logger.getLogger(Vogel.class.getName()).log(Level.SEVERE,null,ex);
}
}
}
问题在于:

 Iterator<String> it = list.iterator();

 while (it.hasNext()) {
   id = Integer.parseInt(it.next());
   out.print("<tr>");
   for (int i = 0; i < 5; i++) {
       out.print("<td>");
       out.print(it.next());
       out.print("</td>");
 }

您应该发布异常的stacktrace
 Iterator<String> it = list.iterator();

 while (it.hasNext()) {
   String item = (String)it.next();
   id = Integer.parseInt(item);
   out.print("<tr>");
   for (int i = 0; i < 5; i++) {
       out.print("<td>");
       out.print(item);
       out.print("</td>");
 }