今日内容
- 用户信息列表展示
- 简单功能
- 列表查询
- 登录
- 添加
- 删除
- 修改
- 复杂功能
- 删除选中
- 分页查询
- 好处：
- 减轻服务器内存的开销
- 提升用户体验
- 复杂条件查询
- 涉及相关技术：Servlet+JSP+MySQL+JDBCTempleat+Duird+BeanUtilS+tomcat
今日源码：
链接：https://pan.baidu.com/s/1TrgVXlXn6cYG3Jz1-Y_bFQ
提取码：e9de
案例：用户信息列表展示
1. 需求：用户信息的增删改查操作
目标：完成下图中的所有功能
2. 设计：
1. 技术选型：
Servlet+JSP+MySQL+JDBCTempleat+Duird+BeanUtilS+tomcat
2. 数据库设计：
create database day17; -- 创建数据库
use day17; -- 使用数据库
create table user( -- 创建表
id int primary key auto_increment,
name varchar(20) not null,
gender varchar(5),
age int,
address varchar(32),
qq varchar(20),
email varchar(50)
);
3. 开发：
1. 环境搭建
- 创建数据库环境
- 创建项目，导入需要的jar包
2. 编码
2.1登录功能
效果：
测试：输入错误验证码效果
输入错误账户密码：
代码：
登录界面代码： login.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="utf-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=edge"/>
<meta name="viewport" content="width=device-width, initial-scale=1"/>
<title>管理员登录</title>
<!-- 1. 导入CSS的全局样式 -->
<link href="css/bootstrap.min.css" rel="stylesheet">
<!-- 2. jQuery导入，建议使用1.9以上的版本 -->
<script src="js/jquery-2.1.0.min.js"></script>
<!-- 3. 导入bootstrap的js文件 -->
<script src="js/bootstrap.min.js"></script>
<script type="text/javascript">
</script>
<script>
window.onload = function(){
document.getElementById("vcode").onclick = function(){
this.src="${pageContext.request.contextPath}/checkCodeServlet?time="+new Date().getTime();
}
}
</script>
</head>
<body>
<div class="container" style="width: 400px;">
<h3 style="text-align: center;">管理员登录</h3>
<form action="${pageContext.request.contextPath}/loginServlet" method="post">
<div class="form-group">
<label for="user">用户名：</label>
<input type="text" name="username" class="form-control" id="user" placeholder="请输入用户名"/>
</div>
<div class="form-group">
<label for="password">密码：</label>
<input type="password" name="password" class="form-control" id="password" placeholder="请输入密码"/>
</div>
<div class="form-inline">
<label for="vcode">验证码：</label>
<input type="text" name="verifycode" class="form-control" id="verifycode" placeholder="请输入验证码" style="width: 120px;"/>
<a href="javascript:refreshCode();">
<img src="${pageContext.request.contextPath}/checkCodeServlet" title="看不清点击刷新" id="vcode"/>
</a>
</div>
<hr/>
<div class="form-group" style="text-align: center;">
<input class="btn btn btn-primary" type="submit" value="登录">
</div>
</form>
<!-- 出错显示的信息框 -->
<div class="alert alert-warning alert-dismissible" role="alert">
<button type="button" class="close" data-dismiss="alert" >
<span>×</span></button>
<strong>${login_msg}</strong>
</div>
</div>
</body>
</html>
验证码校验Servlet： CheckCodeServlet.java
package cn.wbslz.web.servlet;
import javax.imageio.ImageIO;
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 java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;
/**
* 验证码
*/
@WebServlet("/checkCodeServlet")
public class CheckCodeServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
//服务器通知浏览器不要缓存
response.setHeader("pragma","no-cache");
response.setHeader("cache-control","no-cache");
response.setHeader("expires","0");
//在内存中创建一个长80，宽30的图片，默认黑色背景
//参数一：长
//参数二：宽
//参数三：颜色
int width = 80;
int height = 30;
BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
//获取画笔
Graphics g = image.getGraphics();
//设置画笔颜色为灰色
g.setColor(Color.GRAY);
//填充图片
g.fillRect(0,0, width,height);
//产生4个随机验证码，12Ey
String checkCode = getCheckCode();
//将验证码放入HttpSession中
request.getSession().setAttribute("CHECKCODE_SERVER",checkCode);
//设置画笔颜色为黄色
g.setColor(Color.YELLOW);
//设置字体的小大
g.setFont(new Font("黑体",Font.BOLD,24));
//向图片上写入验证码
g.drawString(checkCode,15,25);
//将内存中的图片输出到浏览器
//参数一：图片对象
//参数二：图片的格式，如PNG,JPG,GIF
//参数三：图片输出到哪里去
ImageIO.write(image,"PNG",response.getOutputStream());
}
/**
* 产生4位随机字符串
*/
private String getCheckCode() {
String base = "0123456789ABCDEFGabcdefg";
int size = base.length();
Random r = new Random();
StringBuffer sb = new StringBuffer();
for(int i=1;i<=4;i++){
//产生0到size-1的随机值
int index = r.nextInt(size);
//在base字符串中获取下标为index的字符
char c = base.charAt(index);
//将c放入到StringBuffer中去
sb.append(c);
}
return sb.toString();
}
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request,response);
}
}
2.2 欢迎界面
代码
index.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="utf-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=edge"/>
<meta name="viewport" content="width=device-width, initial-scale=1"/>
<title>首页</title>
<!-- 1. 导入CSS的全局样式 -->
<link href="css/bootstrap.min.css" rel="stylesheet">
<!-- 2. jQuery导入，建议使用1.9以上的版本 -->
<script src="js/jquery-2.1.0.min.js"></script>
<!-- 3. 导入bootstrap的js文件 -->
<script src="js/bootstrap.min.js"></script>
<script type="text/javascript">
</script>
</head>
<body>
<div>${user.name},欢迎您！</div>
<div align="center">
<a
href="${pageContext.request.contextPath}/findUserByPageServlet" style="text-decoration:none;font-size:33px">查询所有用户信息
</a>
</div>
</body>
</html>
2.3查询结果界面
效果：
2.4 添加用户功能
- 分析
编码：
- add.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!-- HTML5文档-->
<!DOCTYPE html>
<!-- 网页使用的语言 -->
<html lang="zh-CN">
<head>
<!-- 指定字符集 -->
<meta charset="utf-8">
<!-- 使用Edge最新的浏览器的渲染方式 -->
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<!-- viewport视口：网页可以根据设置的宽度自动进行适配，在浏览器的内部虚拟一个容器，容器的宽度与设备的宽度相同。
width: 默认宽度与设备的宽度相同
initial-scale: 初始的缩放比，为1:1 -->
<meta name="viewport" content="width=device-width, initial-scale=1">
<!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ -->
<title>添加用户</title>
<!-- 1. 导入CSS的全局样式 -->
<link href="css/bootstrap.min.css" rel="stylesheet">
<!-- 2. jQuery导入，建议使用1.9以上的版本 -->
<script src="js/jquery-2.1.0.min.js"></script>
<!-- 3. 导入bootstrap的js文件 -->
<script src="js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
<center><h3>添加联系人页面</h3></center>
<form action="${pageContext.request.contextPath}/addUserServlet" method="post">
<div class="form-group">
<label for="name">姓名：</label>
<input type="text" class="form-control" id="name" name="name" placeholder="请输入姓名">
</div>
<div class="form-group">
<label>性别：</label>
<input type="radio" name="gender" value="男" checked="checked"/>男
<input type="radio" name="gender" value="女"/>女
</div>
<div class="form-group">
<label for="age">年龄：</label>
<input type="text" class="form-control" id="age" name="age" placeholder="请输入年龄">
</div>
<div class="form-group">
<label for="address">籍贯：</label>
<select name="address" class="form-control" id="address">
<option value="广东">广东</option>
<option value="广西">广西</option>
<option value="湖南">湖南</option>
</select>
</div>
<div class="form-group">
<label for="qq">QQ：</label>
<input type="text" class="form-control" id="qq" name="qq" placeholder="请输入QQ号码"/>
</div>
<div class="form-group">
<label for="email">Email：</label>
<input type="text" class="form-control" id="email" name="email" placeholder="请输入邮箱地址"/>
</div>
<div class="form-group" style="text-align: center">
<input class="btn btn-primary" type="submit" value="提交" />
<input class="btn btn-default" type="reset" value="重置" />
<input class="btn btn-default" type="button" value="返回" />
</div>
</form>
</div>
</body>
- AddUserServlet
package cn.wbslz.web.servlet;
import cn.wbslz.domain.User;
import cn.wbslz.service.UserService;
import cn.wbslz.service.impl.UserServiceImpl;
import org.apache.commons.beanutils.BeanUtils;
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 java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.util.Map;
@WebServlet("/addUserServlet")
public class AddUserServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1设置编码
request.setCharacterEncoding("utf-8");
//2.获取参数
Map<String, String[]> map = request.getParameterMap();
//3.封装对象
User user = new User();
try {
BeanUtils.populate(user,map);
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
//4.调用service保存
UserService service = new UserServiceImpl();
service.addUser(user);
//5.跳转到userListServlet
response.sendRedirect(request.getContextPath()+"/findUserByPageServlet");
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
}
- UserService接口
/**
* 保存对象
* @param user
*/
void addUser(User user);
- UserServiceImpl实现类
private UserDao dao = new UserDaoImpl();
@Override
public void addUser(User user) {
dao.add(user);
}
- UserDao接口
/**
* 添加用户
* @param user
*/
void add(User user);
- UserDaoImpl实现类
@Override
public void add(User user) {
//1 定义sql
String sql = "insert into user values(null,?,?,?,?,?,?,null,null)";
//2执行sql
template.update(sql,user.getName(),user.getGender(),user.getAge(),user.getAddress(),user.getQq(),user.getEmail());
}
界面效果：
2.5 删除功能
分析：
编码：
- delUserServlet
package cn.wbslz.web.servlet;
import cn.wbslz.service.UserService;
import cn.wbslz.service.impl.UserServiceImpl;
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 java.io.IOException;
@WebServlet("/delUserServlet")
public class DelUserServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1 获取id
String id = request.getParameter("id");
//2 调用service删除
UserService service = new UserServiceImpl();
service.deleteUser(id);
//3 跳转到查询所有页面
response.sendRedirect(request.getContextPath()+"/findUserByPageServlet");
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
}
- UserService接口
/**
* 根据id删除user
* @param id
*/
void deleteUser(String id);
- UserServiceImpl实现类
@Override
public void deleteUser(String id) {
dao.delete(Integer.parseInt(id));
}
- UserDao接口
/**
* 删除用户
* @param id
*/
void delete(int id);
- UserDaoImpl实现类
@Override
public void delete(int id) {
//1 定义sql
String sql = "delete from user where id = ?";
//2.执行
template.update(sql,id);
}
演示效果：
2.6 修改功能
- 分析
- 编码：
- FindUserServlet
package cn.wbslz.web.servlet;
import cn.wbslz.domain.User;
import cn.wbslz.service.UserService;
import cn.wbslz.service.impl.UserServiceImpl;
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 java.io.IOException;
@WebServlet("/findUserServlet")
public class FindUserServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1.获取id
String id = request.getParameter("id");
//2.调用service
UserService service = new UserServiceImpl();
User user = service.findUserById(id);
//3.将user存入request
request.setAttribute("user",user);
//4.转发到update.jsp
request.getRequestDispatcher("/update.jsp").forward(request,response);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
}
- Update.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<!-- 网页使用的语言 -->
<html lang="zh-CN">
<head>
<!-- 指定字符集 -->
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>修改用户</title>
<link href="css/bootstrap.min.css" rel="stylesheet">
<script src="js/jquery-2.1.0.min.js"></script>
<script src="js/bootstrap.min.js"></script>
</head>
<body>
<div class="container" style="width: 400px;">
<h3 style="text-align: center;">修改联系人</h3>
<form action="${pageContext.request.contextPath}/updateUserServlet" method="post">
<input type="hidden" name="id" value="${user.id}"><%--隐藏域，传id--%>
<div class="form-group">
<label for="name">姓名：</label>
<input type="text" class="form-control" id="name" name="name" value="${user.name}" readonly="readonly" placeholder="请输入姓名" />
</div>
<div class="form-group">
<label>性别：</label>
<c:if test="${user.gender == '男' }">
<input type="radio" name="gender" value="男" checked />男
<input type="radio" name="gender" value="女" />女
</c:if>
<c:if test="${user.gender == '女' }">
<input type="radio" name="gender" value="男" />男
<input type="radio" name="gender" value="女" checked />女
</c:if>
</div>
<div class="form-group">
<label for="age">年龄：</label>
<input type="text" class="form-control" id="age" name="age" value="${user.age}" placeholder="请输入年龄" />
</div>
<div class="form-group">
<label for="address">籍贯：</label>
<select name="address" id="address" class="form-control" >
<c:if test="${user.address == '北京' }">
<option value="北京" selected>北京</option>
<option value="上海">上海</option>
<option value="广州">广州</option>
</c:if>
<c:if test="${user.address == '上海' }">
<option value="北京" >北京</option>
<option value="上海" selected>上海</option>
<option value="广州">广州</option>
</c:if>
<c:if test="${user.address == '广州' }">
<option value="北京" >北京</option>
<option value="上海">上海</option>
<option value="广州" selected>广州</option>
</c:if>
</select>
</div>
<div class="form-group">
<label for="qq">QQ：</label>
<input type="text" class="form-control" id="qq" name="qq" value="${user.qq}" placeholder="请输入QQ号码"/>
</div>
<div class="form-group">
<label for="email">Email：</label>
<input type="text" class="form-control" id="email" name="email" value="${user.email}" placeholder="请输入邮箱地址"/>
</div>
<div class="form-group" style="text-align: center">
<input class="btn btn-primary" type="submit" value="提交" />
<input class="btn btn-default" type="reset" value="重置" />
<input class="btn btn-default" type="button" value="返回"/>
</div>
</form>
</div>
</body>
</html>
- UpdateUserServlet
package cn.wbslz.web.servlet;
import cn.wbslz.domain.User;
import cn.wbslz.service.UserService;
import cn.wbslz.service.impl.UserServiceImpl;
import org.apache.commons.beanutils.BeanUtils;
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 java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.util.Map;
@WebServlet("/updateUserServlet")
public class UpdateUserServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1，设置编码
request.setCharacterEncoding("utf-8");
//2.获取map
Map<String, String[]> map = request.getParameterMap();
//3.封装对象
User user = new User();
try {
BeanUtils.populate(user,map);
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
//4.调用service修改
UserService service = new UserServiceImpl();
service.updateUser(user);
//5.跳转到查询所有Servlet
response.sendRedirect(request.getContextPath()+"/findUserByPageServlet");
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
}
- UserService接口
/**
*根据id查询
* @param id
* @return
*/
User findUserById(String id);
/**
* 修改用户信息
* @param user
*/
void updateUser(User user);
- UserServiceImpl实现类
@Override
public User findUserById(String id) {
return dao.findById(Integer.parseInt(id));
}
@Override
public void updateUser(User user) {
dao.update(user);
}
- UserDao接口
/**
* 根据id查询用户
* @param id
* @return
*/
User findById(int id);
/**
* 修改用户
* @param user
*/
void update(User user);
- UserDaoImpl实现类
@Override
public User findById(int id) {
//1定义sql
String sql = "select * from user where id = ?";
//2.执行
return template.queryForObject(sql,new BeanPropertyRowMapper<User>(User.class),id);
}
@Override
public void update(User user) {
//1定义sql
String sql = "update user set name = ?,gender = ?,age = ?, address = ?,qq = ?,email = ? where id = ?";
//2.执行
template.update(sql,user.getName(),user.getGender(),user.getAge(),user.getAddress(),user.getQq(),user.getEmail(),user.getId());
}
- 效果演示
2.7 删除选中功能
- 分析
- 编码：
- delSelectedServlet
package cn.wbslz.web.servlet;
import cn.wbslz.domain.User;
import cn.wbslz.service.UserService;
import cn.wbslz.service.impl.UserServiceImpl;
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 java.io.IOException;
@WebServlet("/delSelectedServlet")
public class DelSelectedServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//获取所有id
String[] ids = request.getParameterValues("uid");
//2.调用service删除
UserService service = new UserServiceImpl();
service.delSelectedUser(ids);
//3.跳转到查询所有Servlet
response.sendRedirect(request.getContextPath()+"/findUserByPageServlet");
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
}
- UserService接口
/**
* 批量删除用户
* @param ids
* @return
*/
void delSelectedUser(String[] ids);
- UserServiceImpl实现类: 这里循环复用删除单个用户方法
@Override
public void delSelectedUser(String[] ids) {
if(ids != null && ids.length>0){
//1.遍历数组
for(String id: ids){
//2.调用dao删除
dao.delete(Integer.parseInt(id));
}
}
}
- UserDao接口
/**
* 删除用户
* @param id
*/
void delete(int id);
- UserDaoImpl实现类
@Override
public void delete(int id) {
//1 定义sql
String sql = "delete from user where id = ?";
//2.执行
template.update(sql,id);
}
- 效果演示
2.8 分页查询功能（重点）
分析
编码：
- FindUserByPageServlet
package cn.wbslz.web.servlet;
import cn.wbslz.domain.PageBean;
import cn.wbslz.domain.User;
import cn.wbslz.service.UserService;
import cn.wbslz.service.impl.UserServiceImpl;
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 java.io.IOException;
import java.util.Map;
@WebServlet("/findUserByPageServlet")
public class FindUserByPageServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
//1.获取参数
String currentPage = request.getParameter("currentPage");//当前页码
String rows = request.getParameter("rows");//每页显示条数
if(currentPage == null || "".equals(currentPage)){
currentPage = "1";
}
if(rows == null || "".equals(rows)){
rows = "5";
}
//获取条件查询的参数
Map<String, String[]> condition = request.getParameterMap();
//2.调用service查询
UserService service = new UserServiceImpl();
PageBean<User> pb = service.findUserByPage(currentPage,rows,condition);
System.out.println(pb);//测试用
//3.将PageBean出入request
request.setAttribute("pb",pb);
request.setAttribute("condition",condition);//将查询条件也存入
//4.转发到list.jsp
request.getRequestDispatcher("/list.jsp").forward(request,response);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
}
- UserService接口
/**
* 分页条件查询
* @param currentPage
* @param rows
* @param condition
* @return
*/
PageBean<User> findUserByPage(String currentPage, String rows, Map<String, String[]> condition);
}
- UserServiceImpl实现类
@Override
public PageBean<User> findUserByPage(String _currentPage, String _rows, Map<String, String[]> condition) {
int currentPage = Integer.parseInt(_currentPage);
int rows = Integer.parseInt(_rows);
if(currentPage <= 0){//当前页小于0，则设置为1
currentPage = 1;
}
//1.创建空的PageBean对象
PageBean<User> pb = new PageBean<User>();
//2.调用dao查询总记录数
int totalCount = dao.findTotalCount(condition);
pb.setTotalCount(totalCount);
//3.设置参数
pb.setCurrentPage(currentPage);
pb.setRows(rows);
//4.计算总页码
int totalPage = (totalCount % rows) == 0 ? (totalCount/rows) : (totalCount/rows) +1;
pb.setTotalPage(totalPage);
if(currentPage >= totalPage){//当前页大于最大页，则设置为totalCount
currentPage = totalPage;
}
//5.调用dao查询List集合
//计算开始的记录
int start = (currentPage - 1) * rows;
List<User> list = dao.findByPage(start,rows,condition);
pb.setList(list);
return pb;
}
- UserDao接口
/**
* 查询总记录数
* @return
* @param condition
*/
int findTotalCount(Map<String, String[]> condition);
/**
* 分页查询每页记录
* @param start
* @param rows
* @param condition
* @return
*/
List<User> findByPage(int start, int rows, Map<String, String[]> condition);
- UserDaoImpl实现类
@Override
public int findTotalCount(Map<String, String[]> condition) {
//1.定义模板初始化sql,
String sql = "select count(*) from user where 1=1 ";
StringBuilder sb = new StringBuilder(sql);
//2.遍历map
Set<String> keySet = condition.keySet();
//定义参数集合
List<Object> params = new ArrayList<Object>();
for(String key : keySet){
//排除分页条件参数
if("currentPage".equals(key) || "rows".equals(key)){
continue;
}
//获取value
String value = condition.get(key)[0];
//判断value是否有值
if(value != null && !"".equals(value)){
//有值
sb.append(" and "+key+" like ? ");
params.add("%"+value+"%");//？条件的值
}
}
System.out.println(sb.toString());//测试
System.out.println(params);//测试
return template.queryForObject(sb.toString(),Integer.class,params.toArray());
}
@Override
public List<User> findByPage(int start, int rows, Map<String, String[]> condition) {
String sql = "select * from user where 1 = 1";
StringBuilder sb = new StringBuilder(sql);
//2.遍历map
Set<String> keySet = condition.keySet();
//定义参数集合
List<Object> params = new ArrayList<Object>();
for(String key : keySet){
//排除分页条件参数
if("currentPage".equals(key) || "rows".equals(key)){
continue;
}
//获取value
String value = condition.get(key)[0];
//判断value是否有值
if(value != null && !"".equals(value)){
//有值
sb.append(" and "+key+" like ? ");
params.add("%"+value+"%");//？条件的值
}
}
//添加分页查询
sb.append(" limit ?,? ");
//添加分页查询参数
params.add(start);
params.add(rows);
sql = sb.toString();
System.out.println(sql);
System.out.println(params);
return template.query(sql,new BeanPropertyRowMapper<User>(User.class),params.toArray());
}
- 效果：
2.9 复杂条件分页查询功能（重点）
- 分析：
- 编码：
- 包含在2.9分页查询里
- 效果
可以在控制台查看到，查询sql是动态变化的
4. 测试
略
5. 部署运维
使用tomcat服务器项目
6. 总结
该项目是融合了从前40天所学内容的整合项目，是对之前所学知识的实践性检验，对训练基础知识很有帮助。
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