在jsp页面 里加一个下拉菜单。里面数据 分别为A B C有一个sql2000的数据库。表里 有A B C三列。点击下拉菜单里的ABC选项。点A就选取数据库里 A 列的值点B就选取数据库里 B 列的值。。然后显示出来。该开始学习ecplise的做小系统。请有人知道 完整的代码该怎么写么。只需要最简单，基础的代码就可以了。谢了。。
//完成了如果还有什么不清楚可以问<%@ page contentType="text/html; charset=gbk" %> <%@ page language="java" import="java.util.*" pageEncoding="gbk"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> </head> <body> <%//List list=(List)request.getAttribute("selelist"); //需要自己后台设入( request.setAttribute("selelist",list);)我这里做个测试list写死 List list = new ArrayList(); list.add("aaa"); list.add("bbb"); list.add("ccc"); Iterator it = list.iterator(); %> <select style=""> <option>请选择</option> <%while (it.hasNext()){ %> <option><%=it.next().toString()%></option> <% } %> </select> </body> </html>
谢谢。是不是 还要写个 action 和 DAO 以及 Bean 然后就可以调试运行了。list需要在单独的java文件里定义么
太感谢了。我以前都没接触过eclipse 现在刚开始学呵呵
<select name="sel" onchage="test()"></select><script> function test(){ var choose=document.form.sel.value; location.href="test.jsp?ch="+choose; } </script><% String ch=request.getParameter("ch"); ch=ch==null?"A":ch; String sql="select "+ch+" from test"; //下面进行查询会了吧！ List list = new ArrayList(); try { // 获取连接 con = ConnectionManager.getCon();//获取连接应该会写吧~ ps = con.prepareStatement(sql); rs = ps.executeQuery(); while (rs.next()) {
<%@ page language="java" import="java.util.*" pageEncoding="gbk"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
</head>
<body>
<%//List list=(List)request.getAttribute("selelist");
//需要自己后台设入( request.setAttribute("selelist",list);)我这里做个测试list写死
List list = new ArrayList();
list.add("aaa");
list.add("bbb");
list.add("ccc");
Iterator it = list.iterator();
%>
<select style="">
<option>请选择</option>
<%while (it.hasNext()){ %>
<option><%=it.next().toString()%></option>
<% } %>
</select>
</body>
</html>
function test(){
var choose=document.form.sel.value;
location.href="test.jsp?ch="+choose;
}
</script><%
String ch=request.getParameter("ch");
ch=ch==null?"A":ch;
String sql="select "+ch+" from test";
//下面进行查询会了吧！
List list = new ArrayList(); try {
// 获取连接
con = ConnectionManager.getCon();//获取连接应该会写吧~
ps = con.prepareStatement(sql);
rs = ps.executeQuery();
while (rs.next()) {
list.add(rs.getString(1));
} } catch (Exception e) {
// TODO: handle exception
} finally {
// 释放
ConnectionManager.closeAll(rs, ps, con);
} for(int i=0;i<list.size();i++){
out.print(list.get(i));//循环打印出来即可
}
%>
index.jsp
<%@ page contentType="text/html; charset=gbk" %>
<%@ page language="java" import="java.util.*" pageEncoding="gbk"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
</head>
<body>
<%//List list=(List)request.getAttribute("selelist");
//需要自己后台设入( request.setAttribute("selelist",list);)我这里做个测试list写死
List list = new ArrayList();
list.add("aaa");
list.add("bbb");
list.add("ccc");
Iterator it = list.iterator();
%>
<select style="">
<option>请选择</option>
<%while (it.hasNext()){ %>
<option><%=it.next().toString()%></option>
<% } %>
</select>
<input type="button" value="测试" onclick='javascript:window.location="<%=request.getContextPath() %>/test"'>
</body>
</html>test.jsp
<%@ page contentType="text/html; charset=gbk" %>
<%@ page language="java" import="java.util.*" pageEncoding="gbk"%>
<%@ page import="com.VO"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
</head>
<body>
<%List<VO> list=(List<VO>)request.getSession().getAttribute("seleList");%>
A:<select style="">
<option>请选择</option>
<%for(VO vo:list){ %>
<option><%=vo.getA()%></option>
<% } %>
</select>
B:<select style="">
<option>请选择</option>
<%for(VO vo:list){ %>
<option><%=vo.getB()%></option>
<% } %>
</select>
C:<select style="">
<option>请选择</option>
<%for(VO vo:list){ %>
<option><%=vo.getC()%></option>
<% } %>
</select>
</body>
</html>
web.xml<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<servlet> <description>TestServlet</description>
<display-name>Test</display-name>
<servlet-name>Test</servlet-name>
<servlet-class>com.TestServlet</servlet-class> </servlet>
<servlet-mapping>
<servlet-name>Test</servlet-name>
<url-pattern>/test</url-pattern>
</servlet-mapping>
</web-app>
package com;
/**
* 显示ABC
* @author Administrator
*
*/
public class VO {
String a;
String b;
String c;
public String getA() {
return a;
}
public void setA(String a) {
this.a = a;
}
public String getB() {
return b;
}
public void setB(String b) {
this.b = b;
}
public String getC() {
return c;
}
public void setC(String c) {
this.c = c;
}
}package com;/**
* DAO代码我就不写了
*/
import java.util.ArrayList;
import java.util.List;public class DAO {
/**
* 数据库逻辑我就 不写了
* @return
*/
public List<VO> getABC(){
List<VO> list = new ArrayList<VO>();
for(int i = 0;i<8;i++){
VO vo = new VO();
vo.setA("aaa"+i);
vo.setB("bbb"+i);
vo.setC("ccc"+i);
list.add(vo);
}
return list;
}
}[code=Java]
[/code]
package com;import java.io.IOException;
import java.util.List;import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
//业务处理
public class TestServlet extends HttpServlet{ @Override
protected void doGet(HttpServletRequest arg0, HttpServletResponse arg1) throws ServletException, IOException {
// TODO Auto-generated method stub
this.doPost(arg0, arg1);
} @Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
List<VO> list = new DAO().getABC();
request.getSession().setAttribute("seleList", list);
response.sendRedirect("test.jsp");
}
}
用的是tomcat吧
如果还不行就留个油箱发给你吧
建议用用Struts标签很简单的