MVC模式信息查询
程序员文章站
2024-03-16 21:59:34
...
1.查询：
（1）Userinfo数据库
（2）user.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!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>用户信息</title>
<link rel="stylesheet" href="/dabaMVC/resources/css/bootstrap.min.css">
<script src="/dabaMVC/resources/js/jquery.js"></script>
<script src="/dabaMVC/resources/js/bootstrap.min.js"></script>
</head>
<body>
<div class="col-md-2">
<form action="queryUser.do" method="post">
<input type="text" size=1 name="userId" class="form-control"
placeholder="请输入用户编号" /> <input type="submit" value="查询"
class="btn btn-success" />
</form>
</div>
<c:if test="${!empty requestScope.users }">
<table class="table table-hover">
<thead>
<tr>
<th>用户编号</th>
<th>用户名</th>
<th>密码</th>
</tr>
</thead>
<c:forEach items="${requestScope.users}" var="user">
<tbody>
<tr>
<td>${user.id}</td>
<td>${user.name}</td>
<td>${user.password}</td>
</tr>
</tbody>
</c:forEach>
</table>
</c:if>
</body>
</html>（3）Dao，DaoImpl
public interface UserDao {
public List<User> getAll();
}
public class UserDaoImpl extends DAO<User> implements UserDao {
@Override
public List<User> getAll() {
String sql="SELECT * FROM userinfo";
return getForList(sql);
}
}
（4）servlet
private void queryUser(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
List<User> users=userDao.getAll(); request.setAttribute("users", users); request.getRequestDispatcher("/jsp/user.jsp").forward(request, response);
}
运行效果如下：
（5）domain较容易未展示
2.模糊查询（还以用户表为例）
（1）CriteriaUser.java（最好重建）
public class CriteriaUser {
private String name;
public String getName() {
if (name==null) {
name="%%";
}
else {
name="%"+name+"%";
}
return name;
}
public void setName(String name) {
this.name = name;
}
@Override
public String toString() {
return "CriteriaUser [name=" + name + "]";
}
public CriteriaUser(String name) {
super();
this.name = name;
}
（2）jsp页面同上，表单换成对name操作（string）
（3）Dao，DaoImpl
import java.util.List;
import com.dabaMVC.model.CriteriaUser;
import com.dabaMVC.model.Cyg;
import com.dabaMVC.model.User;
public interface UserDao {
public List<User> getAll();
//获取重复字段
public long getCountWithName(String name);
//模糊查询
public List<User> getForListWithUser(CriteriaUser criteriaUser);
}
public class UserDaoImpl extends DAO<User> implements UserDao {
@Override
public List<User> getAll() {
String sql="SELECT * FROM userinfo";
return getForList(sql);
}
@Override
public User query(Integer id) {
String sql = "SELECT * FROM userinfo WHERE id = ?";
return query(sql, id);
}
@Override
public long getCountWithName(String name) {
String sql="select count(name) from userinfo where name = ? ";
return getForValue(sql,name);
}
@Override
public List<User> getForListWithUser(CriteriaUser criteriaUser) {
String sql="select * from userinfo where name like ? ";
return getForList(sql, criteriaUser.getName());
}
}
（4）servlet
private void queryCriteriaUser(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
request.setCharacterEncoding("UTF-8");
String name=request.getParameter("name");
CriteriaUser criteriaUser=new CriteriaUser(name);
List<User> users=userDao.getForListWithUser(criteriaUser);
request.setAttribute("users",users);
request.getRequestDispatcher("/jsp/user.jsp").forward(request, response);
}
“`
运行效果如下：