1、实现根据姓名查询收支记录功能
（1）ResearchByName
package com.edu.servlet;
import java.io.IOException;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.edu.dao.Userdao;
import com.edu.entity.User;
@WebServlet("/ResearchByName")
public class ResearchByName extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.getRequestDispatcher("utf-8");
response.setCharacterEncoding("utf-8");
String name = request.getParameter("username");
Userdao dao = new Userdao();
List<User> lists = dao.ResearchName(name);
if(lists != null && lists.size()!=0) {
System.out.println("查询成功！！！");
request.setAttribute("list", lists);
request.getRequestDispatcher("/Showname.jsp").forward(request, response);
}
else {
System.out.println("查询失败！！！");
request.getRequestDispatcher("/Showname.jsp").forward(request, response);
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
（2）dao
public List<User> ResearchName(String name){
List<User> list = new ArrayList<User>();
Connection conn = DbHelper.getConnection();
String sql = "select * from userno where username = ?";
try {
PreparedStatement pst = conn.prepareStatement(sql);
pst.setString(1, name);
ResultSet rst = pst.executeQuery();
while(rst.next()) {
User user = new User();
user.setId(rst.getInt("id"));
user.setUsername(rst.getString("username"));
user.setUserused(rst.getString("userused"));
user.setUsermoney(rst.getString("usermoney"));
user.setUsedate(rst.getDate("usedate"));
list.add(user);
}
rst.close();
pst.close();
} catch (SQLException e) {
// TODO 自动生成的 catch 块
e.printStackTrace();
}
return list;
}
2、实现根据收支编号查询功能
（1）dao
public User ResearchId(int id) {
Connection conn = DbHelper.getConnection();
String sql = "select * from userno where id = ?";
ResultSet rst = null;
User user = new User();
try {
PreparedStatement pst = conn.prepareStatement(sql);
pst.setInt(1, id);
rst = pst.executeQuery();
while(rst.next()) {
user.setId(rst.getInt("id"));
user.setUsername(rst.getString("username"));
user.setUserused(rst.getString("userused"));
user.setUsermoney(rst.getString("usermoney"));
user.setUsedate(rst.getDate("usedate"));
}
rst.close();
pst.close();
} catch (SQLException e) {
// TODO 自动生成的 catch 块
e.printStackTrace();
}
// TODO 自动生成的方法存根
return user;
}
3、遍历所有收支信息
（1）Showservlet
package com.edu.servlet;
import java.io.IOException;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.edu.dao.Userdao;
import com.edu.entity.User;
@WebServlet("/Showservlet")
public class Showservlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
Userdao dao = new Userdao();
List<User> list = dao.showAll();
request.setAttribute("list", list);
request.getRequestDispatcher("/Showall.jsp").forward(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
（2）dao
public List<User> showAll(){
List<User> list = new ArrayList<User>();
Connection conn = DbHelper.getConnection();
String sql = "select * from userno";
try {
PreparedStatement pst = conn.prepareStatement(sql);
ResultSet rst = pst.executeQuery();
while(rst.next()) {
User user = new User();
user.setId(rst.getInt("id"));
user.setUsername(rst.getString("username"));
user.setUserused(rst.getString("userused"));
user.setUsermoney(rst.getString("usermoney"));
user.setUsedate(rst.getDate("usedate"));
list.add(user);
}
rst.close();
pst.close();
} catch (SQLException e) {
// TODO 自动生成的 catch 块
e.printStackTrace();
}
return list;
}