我是一个java web的初学者,有个很简单的问题想请教一下各位好心人,
是一个很简单的数据库的查询程序,应用mvc(jsp+servlet+javabean以及java类)模式的
就是我在一个页面输入要查询的商品编号或关键字,
单击确定让后在另一个页面给出查询的所有结果~~
谁能给一个较完整的代码,谢谢。
我的数据库是sql server 2000,查询一个表就可以。
小弟感激不尽~~~~~~~~~~
是一个很简单的数据库的查询程序,应用mvc(jsp+servlet+javabean以及java类)模式的
就是我在一个页面输入要查询的商品编号或关键字,
单击确定让后在另一个页面给出查询的所有结果~~
谁能给一个较完整的代码,谢谢。
我的数据库是sql server 2000,查询一个表就可以。
小弟感激不尽~~~~~~~~~~
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- onchange="location.href='addVote.jsp?n='+document.form1.n.value;"
<form method="get" action="第二个页面的地址">
输入ID:<input type="text" name="id" />
<input type="submit" />
</form>
第二个页面接参数并查询输出
id从request.getParameter("id")拿,然后去查就行了
private String dbDriver = "com.mysql.jdbc.Driver"; // 数据库的驱动 private String url = "jdbc:mysql://localhost/learnjsp"; // URL地址 public Connection connection = null; public DBConnection() {
try {
Class.forName(dbDriver).newInstance(); // 加载数据库驱动
connection = DriverManager.getConnection(url, "root", "123456"); // 加载数据库
} catch (Exception ex) {
System.out.println("数据库加载失败!"+ex.toString());
}
}
}
写方法
public class GoodsDao {
private Connection connection = null; //定义连接的对象
private PreparedStatement ps = null; //定义预准备的对象
private DBConnection jdbc = null; //定义数据库连接对象
public GoodsDao() {
jdbc = new DBConnection();
connection = jdbc.connection; //利用构造方法取得数据库连接
}
//全部查询
public List selectGoods() {
List list = new ArrayList();
GoodsEntity goods = null;
try {
ps = connection.prepareStatement("select * from tb_goods order by id DESC");
ResultSet rs = ps.executeQuery();
while (rs.next()) {
goods = new GoodsEntity();
goods.setId(Integer.valueOf(rs.getString(1)));
goods.setBig(Integer.valueOf(rs.getString(2)));
goods.setSmall(Integer.valueOf(rs.getString(3)));
goods.setName(rs.getString(4));
goods.setFrom(rs.getString(5));
goods.setIntroduce(rs.getString(6));
goods.setCreateTime(rs.getString(7));
goods.setOriginalPrice(Float.valueOf(rs.getString(8)));
goods.setCurrentPrice(Float.valueOf(rs.getString(9)));
goods.setNumber(Integer.valueOf(rs.getString(10)));
goods.setPicture(rs.getString(11));
goods.setDiscount(Integer.valueOf(rs.getString(12)));
list.add(goods);
}
}
catch (SQLException ex) {
System.out.println("数据库访问失败");
}
return list;
}
}servlet :作用主要是转向用的
package servlet;import java.io.IOException;
import java.io.PrintWriter;
import java.sql.SQLException;import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import com.mycompany.entity.UserEntity;import dao.GoodsDao;public class LoginServlet extends HttpServlet { /**
* Constructor of the object.
*/
public LoginServlet() {
super();
} /**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
} /**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException { response.setContentType("text/html");
PrintWriter out = response.getWriter();
out
.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
out.print(" This is ");
out.print(this.getClass());
out.println(", using the GET method");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
} /**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException { request.setCharacterEncoding("gb2312");
String name=request.getParameter("name");
String password=request.getParameter("password");
GoodsDao dao=new GoodsDao();
UserEntity user=null;
try {
user = dao.selectUserEntity(name);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
String msg="";
if(user==null)
{
msg="用户名不存在";
request.setAttribute("msg", msg);
this.getServletContext().getRequestDispatcher("/error.jsp").forward(request, response);
}
else
{
String pass=user.getPassword();
if(pass.equals(password))
{
request.getSession().setAttribute("user", user);
response.sendRedirect("/test/index.jsp");
}
else
{
msg="密码错误";
request.setAttribute("msg", msg);
this.getServletContext().getRequestDispatcher("/error.jsp").forward(request, response);
}
}
} /**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occure
*/
public void init() throws ServletException {
// Put your code here
}}
前台输入,显示页面我就不写了,不过提交要配好路径不然会出错的
<form name="form" method="post" action="LoginServlet">