JSP案例——用户信息管理系统
1、需求
简单的用户信息管理系统
对用户信息的增删改查
效果截图（部分）
2、设计
技术选型
Servlet + jsp + Mysql + jdbctemplate + Druid + beanutils + tomccat+bootstrap
数据库设计
CREATE TABLE t_user( -- 创建表id INT PRIMARY KEY AUTO_INCREMENT,NAME VARCHAR(20) NOT NULL,gender VARCHAR(5),age INT,address VARCHAR(32),qqVARCHAR(20),email VARCHAR(50));
3、环境搭建
3.1、创建项目导入jar包
3.2、导入配置文件
druid.properties
driverClassName=com.mysql.jdbc.Driverurl=jdbc:mysql://127.0.0.1:3306/studyusername=rootpassword=123456# 初始化连接对象的大小initialSize=5# 最大连接数maxActive=10# 最大等待时间maxWait=3000
创建包结构
4、编码
功能一：用户数据的展示
1、实体类User
package com.zhou.test.domain;/*** @author it春和* @create -02-27 16:11*/public class User {private int id;private String name;private String gender;private int age;private String address;private String qq;private String email;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getGender() {return gender;}public void setGender(String gender) {this.gender = gender;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}public String getAddress() {return address;}public void setAddress(String address) {this.address = address;}public String getQq() {return qq;}public void setQq(String qq) {this.qq = qq;}public String getEmail() {return email;}public void setEmail(String email) {this.email = email;}@Overridepublic String toString() {return "User{" +"id=" + id +", name='" + name + '\'' +", gender='" + gender + '\'' +", age=" + age +", address='" + address + '\'' +", qq='" + qq + '\'' +", email='" + email + '\'' +'}';}}
2、JdbcUtils
public class JdbcUtils {private static DataSource dataSource;static {try {// 加载配置文件Properties properties = new Properties();InputStream is = JdbcUtils.class.getClassLoader().getResourceAsStream("druid.properties");properties.load(is);// 创建datasourcedataSource = DruidDataSourceFactory.createDataSource(properties);} catch (IOException e) {e.printStackTrace();} catch (Exception e) {e.printStackTrace();}}public static DataSource getDataSource(){return dataSource;}public static Connection getConnection() throws SQLException {return dataSource.getConnection();}}
3、UserDao
// 接口public interface UserDao {/*** 查询所有用户* @return list*/public List<User> findAll();}// 接口的实现类public class UserDaoImpl implements UserDao {// 声明一个jdbctemplateprivate JdbcTemplate template = new JdbcTemplate(JdbcUtils.getDataSource());@Overridepublic List<User> findAll() {List<User> userList = null;try {// 定义sqlString sql = "select * from t_user";// 使用jdbctemplate查询userList = template.query(sql, new BeanPropertyRowMapper<User>(User.class));} catch (DataAccessException e) {e.printStackTrace();}return userList;}}
4、UserService
// 接口public interface UserService {/*** 查询所有用户* @return*/public List<User> findALl();}// 接口的实现类public class UserServiceImpl implements UserService {private UserDao userDao = new UserDaoImpl();@Overridepublic List<User> findALl() {// 调用userdao进行查询List<User> userList = userDao.findAll();return userList;}}
5、FindAllServlet
@WebServlet("/findAllServlet")public class FindAllServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {// 1、调用service进行查询UserService userService = new UserServiceImpl();List<User> users = userService.findALl();// 2、将users存入request域中request.setAttribute("users",users);// 3、转发到数据展示页面request.getRequestDispatcher("/list.jsp").forward(request,response);}@Overrideprotected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doGet(request, response);}}
6、前端页面
index.jsp
list.jsp数据展示的页面
使用jstl循环取出数据 填入表格之中
<%--User: it春和Date: /2/27 16:30--%><%@ page contentType="text/html;charset=UTF-8" language="java" %><%@taglib prefix="c" uri="/jsp/jstl/core" %><!-- 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>用户信息管理系统</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><style type="text/css">td, th {text-align: center;}</style></head><body><div class="container"><h3 style="text-align: center">用户信息列表</h3><table border="1" class="table table-bordered table-hover"><tr class="success"><th>编号</th><th>姓名</th><th>性别</th><th>年龄</th><th>籍贯</th><th>QQ</th><th>邮箱</th><th>操作</th></tr><c:forEach items="${requestScope.users}" var="user" varStatus="u"><tr><td>${user.id}</td><td>${user.name}</td><td>${user.gender}</td><td>${user.age}v</td><td>${user.address}</td><td>${user.qq}</td><td>${user.email}</td><td><a class="btn btn-default btn-sm" href="update.html">修改</a> <a class="btn btn-default btn-sm" href="">删除</a></td></tr></c:forEach><tr><td colspan="8" align="center"><a class="btn btn-primary" href="add.html">添加联系人</a></td></tr></table></div></body></html>
7、运行
功能二：添加用户
1、点击添加用户跳转到add.jdp
2、设置表单的提交路径 addUserServlet
3、获取用户参数信息
4、封装user
5、调用service层进行添加
6、service层调用dao层
userDao
/*** 添加用户的方法* @param user*/public void addUser(User user);@Overridepublic void addUser(User user) {String sql = "insert into t_user values(null,?,?,?,?,?,?)";int i = template.update(sql, user.getName(), user.getGender(), user.getAge(), user.getAddress(), user.getQq(), user.getEmail());}
userService
/*** 添加用户* @param user*/public void addUser(User user);@Overridepublic void addUser(User user) {userDao.addUser(user);}
AddUserServlet
@WebServlet("/addUserServlet")public class AddUserServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {// 设置request的编码 解决中文乱码问题request.setCharacterEncoding("utf-8");// 1、获取所有参数Map<String, String[]> parameterMap = request.getParameterMap();// 2、封装对象User user = new User();try {BeanUtils.populate(user,parameterMap);} catch (IllegalAccessException e) {e.printStackTrace();} catch (InvocationTargetException e) {e.printStackTrace();}// 3、调用service进行添加UserService userService = new UserServiceImpl();userService.addUser(user);// 4、跳转到查询页面response.sendRedirect(request.getContextPath() + "/findAllServlet");}@Overrideprotected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doGet(request, response);}}
前端页面
首先list.jsp中点击超级链挑战到add.jsp
add.jsp中将表单数据提交到AddUserServlet
<%--User: zhouhaoDate: /2/27 22:04--%><%@ page contentType="text/html;charset=UTF-8" language="java" %><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="sex" value="男" checked="checked"/>男<input type="radio" name="sex" 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><option value="广东">湖北</option><option value="广西">河南</option><option value="湖南">河北</option><option value="广东">四川</option><option value="广西">重庆</option><option value="湖南">贵州</option><option value="湖南">云南</option><option value="湖南">新疆</option><option value="湖南">海南</option></select></div><div class="form-group"><label for="qq">QQ：</label><input type="text" class="form-control" name="qq" id="qq" placeholder="请输入QQ号码"/></div><div class="form-group"><label for="email">Email：</label><input type="text" class="form-control" name="email" id="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>
功能三：删除用户
点击删除按钮 传递用户id
根据id进行删除
UserDao
/*** 根据id删除用户* @param id*/public void deleteUser(int id);@Overridepublic void deleteUser(int id) {String sql = "delete from t_user where id = ?";template.update(sql,id);}
UserService
/*** 根据id删除用户* @param id*/public void deleteUser(int id);@Overridepublic void deleteUser(int id) {userDao.deleteUser(id);}
DeleteUserServlet
@WebServlet("/deleteUserServlet")public class DeleteUserServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {// 获取参数idString id = request.getParameter("id");// 将id转为int型int uid = Integer.parseInt(id);// 调用servlce进行删除UserService service = new UserServiceImpl();service.deleteUser(uid);// 重定向到数据展示页面response.sendRedirect(request.getContextPath()+"/findAllServlet");}@Overrideprotected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doGet(request, response);}}
前端页面
功能四：修改用户
点击修改挑战到修改用户信息的界面
回显用户的信息
回显信息
UserDao
/*** 根据id查询出一个用户的所有信息* @param id* @return*/public User findUserById(int id);@Overridepublic User findUserById(int id) {User user = null;try {String sql= "select * from t_user where id = ?";user = template.queryForObject(sql, new BeanPropertyRowMapper<User>(User.class), id);} catch (DataAccessException e) {e.printStackTrace();}return user;}
UserService
/*** 根据id查询一个用户* @param id* @return*/public User findUserById(int id);@Overridepublic User findUserById(int id) {// 调用userdao查询用户信息return userDao.findUserById(id);}
FindeOneUserServlet
@WebServlet("/findOneUser")public class FindOneUserServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {// 获取请求参数String id = request.getParameter("id");int uid = Integer.parseInt(id);// 调用userservice查询UserService userService = new UserServiceImpl();User user = userService.findUserById(uid);// 将user存入request域中request.setAttribute("f_user",user);request.getRequestDispatcher("/update.jsp").forward(request,response);}@Overrideprotected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doGet(request, response);}}
前端页面
数据的回显 在每个表单选项添加value属性
<%--User: it春和Date: /2/28 11:25--%><%@ page contentType="text/html;charset=UTF-8" language="java" %><%@taglib prefix="c" uri="/jsp/jstl/core" %><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="" method="post"><div class="form-group"><label for="name">姓名：</label><input type="text" class="form-control" id="name" name="name" value="${requestScope.f_user.name}"readonly="readonly" placeholder="请输入姓名"/></div><div class="form-group"><label>性别：</label><c:if test="${requestScope.f_user.gender == '男' }"><input type="radio" name="sex" value="男" checked="checked"/>男<input type="radio" name="sex" value="女"/>女</c:if><c:if test="${requestScope.f_user.gender == '女' }"><input type="radio" name="sex" value="男"/>男<input type="radio" name="sex" value="女" checked="checked"/>女</c:if></div><div class="form-group"><label for="age">年龄：</label><input type="text" class="form-control" id="age" value="${requestScope.f_user.age}" name="age"placeholder="请输入年龄"/></div><div class="form-group"><label for="address">籍贯：</label><select name="address" class="form-control" id="address"><c:if test="${requestScope.f_user.address == '广东'}"><option value="广东" selected="selected">广东</option><option value="湖南">湖南</option><option value="湖北">湖北</option><option value="重庆">重庆</option><option value="贵州">贵州</option></c:if><c:if test="${requestScope.f_user.address == '湖南'}"><option value="广东">广东</option><option value="湖南" selected>湖南</option><option value="湖北">湖北</option><option value="重庆">重庆</option><option value="贵州">贵州</option></c:if><c:if test="${requestScope.f_user.address == '湖北'}"><option value="广东">广东</option><option value="湖南">湖南</option><option value="湖北" selected>湖北</option><option value="重庆">重庆</option><option value="贵州">贵州</option></c:if><c:if test="${requestScope.f_user.address == '重庆'}"><option value="广东">广东</option><option value="湖南">湖南</option><option value="湖北">湖北</option><option value="重庆" selected="selected">重庆</option><option value="贵州">贵州</option></c:if><c:if test="${requestScope.f_user.address == '贵州'}"><option value="广东">广东</option><option value="湖南">湖南</option><option value="湖北">湖北</option><option value="重庆">重庆</option><option value="贵州" selected="selected">贵州</option></c:if><option value="广东">广东</option><option value="湖南">湖南</option><option value="湖北">湖北</option><option value="重庆">重庆</option><option value="贵州">贵州</option></select></div><div class="form-group"><label for="qq">QQ：</label><input type="text" class="form-control" name="qq" value="${f_user.qq}" id="qq" placeholder="请输入QQ号码"/></div><div class="form-group"><label for="email">Email：</label><input type="text" class="form-control" name="email" id="email" value="${f_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>
回显效果
功能五、分页查询
定义PageBean
package com.zhou.test.domain;import java.util.List;/*** @author it春和* @create -03-03 23:38*/public class PageBean<T> {private int totalCount; // 总记录数private int currentPage; // 当前页码private int rows; // 每页显示的条数private int totalPage; // 总页数private List<T> list; // 一页显示的数据public int getTotalCount() {return totalCount;}public void setTotalCount(int totalCount) {this.totalCount = totalCount;}public int getCurrentPage() {return currentPage;}public void setCurrentPage(int currentPage) {this.currentPage = currentPage;}public int getRows() {return rows;}public void setRows(int rows) {this.rows = rows;}public int getTotalPage() {return totalPage;}public void setTotalPage(int totalPage) {this.totalPage = totalPage;}public List<T> getList() {return list;}public void setList(List<T> list) {this.list = list;}}
编写UserDao
/*** 查询总记录数* @return*/public int findTotalCount();/*** 分页查询* @param strat 开始索引* @param end 一页查询多少条记录* @return 装在User的集合*/public List<User> findUserByPage(int strat,int end);@Overridepublic int findTotalCount() {String sql = "select count(*) from t_user";Integer integer = template.queryForObject(sql, Integer.class);return integer;}@Overridepublic List<User> findUserByPage(int strat, int end) {String sql = "select * from t_user limit ?,?";List<User> users = template.query(sql, new BeanPropertyRowMapper<User>(User.class), strat, end);return users;}
编写UserService
/*** 分页查询用户* @param currentPage 当前页* @param rows 每页显示的条数* @return 返回一个pagebean对象*/public PageBean<User> findUserByPage(int currentPage,int rows);
@Overridepublic PageBean<User> findUserByPage(int currentPage, int rows) {UserDao userDao = new UserDaoImpl();PageBean<User> userPageBean = new PageBean<>();userPageBean.setCurrentPage(currentPage);userPageBean.setRows(rows);// 查询总记录数int totalCount = userDao.findTotalCount();userPageBean.setTotalCount(totalCount);// 计算总页数 总页数 = totalCount % rows == 0 ? totalCount % rows : totalCount % rows + 1int totalPage = (totalCount % rows) == 0 ? (totalCount % rows) : (totalCount % rows + 1);userPageBean.setTotalPage(totalPage);// 查询每页显示的用户数据 开始索引为 （currentPage-1） * rowsint start = (currentPage - 1) * rows;List<User> userList = userDao.findUserByPage(start, rows);userPageBean.setList(userList);return userPageBean;}
编写Servlet
package com.zhou.test.web;/*** @author it春和* @create -03-03 23:59*/import com.zhou.test.domain.PageBean;import com.zhou.test.domain.User;import com.zhou.test.service.UserService;import com.zhou.test.service.impl.UserServiceImpl;import javax.servlet.*;import javax.servlet.http.*;import javax.servlet.annotation.*;import java.io.IOException;@WebServlet("/findeUserByPageServlet")public class FindeUserByPageServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {// 1、接收参数String currentPage = request.getParameter("currentPage");String rows = request.getParameter("rows");if(currentPage == null || "".equals(currentPage)){currentPage = "1";}if(rows == null || "".equals(rows)){rows = "5";}int _currentPage = Integer.parseInt(currentPage);int _rows = Integer.parseInt(rows);// 2、调用service查询UserService userService = new UserServiceImpl();PageBean<User> pb = userService.findUserByPage(_currentPage, _rows);System.out.println(pb);//3.将PageBean存入requestrequest.setAttribute("pb",pb);//4.转发到list.jsprequest.getRequestDispatcher("/list.jsp").forward(request,response);}@Overrideprotected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doGet(request, response);}}
修改index.jsp
修改list.jsp
修改总记录数总页码的显示
标签遍历 页码
上一页的禁用状态
list.jsp代码
<%--User: it春和Date: /2/27 16:30--%><%@ page contentType="text/html;charset=UTF-8" language="java" %><%@taglib prefix="c" uri="/jsp/jstl/core" %><!-- 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>用户信息管理系统</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><style type="text/css">td, th {text-align: center;}</style></head><body><div class="container"><h3 style="text-align: center">用户信息列表</h3><table border="1" class="table table-bordered table-hover"><tr class="success"><th>编号</th><th>姓名</th><th>性别</th><th>年龄</th><th>籍贯</th><th>QQ</th><th>邮箱</th><th>操作</th></tr><c:forEach items="${requestScope.pb.list}" var="user" varStatus="u"><tr><td>${u.count}</td><td>${user.name}</td><td>${user.gender}</td><td>${user.age}</td><td>${user.address}</td><td>${user.qq}</td><td>${user.email}</td><td><a class="btn btn-default btn-sm"href="${pageContext.request.contextPath}/findOneUser?id=${user.id}">修改</a> <a class="btn btn-default btn-sm"href="${pageContext.request.contextPath}/deleteUserServlet?id=${user.id}">删除</a></td></tr></c:forEach><tr><td colspan="8" align="center"><a class="btn btn-primary" href="add.jsp">添加联系人</a></td></tr></table><%-- 分页条 --%><nav aria-label="Page navigation"><ul class="pagination"><%-- 上一页 --%><c:if test="${requestScope.pb.currentPage == 1}"><li class="disabled"></c:if><c:if test="${requestScope.pb.currentPage != 1}"><li></c:if><a href="${pageContext.request.contextPath}/findeUserByPageServlet?currentPage=${requestScope.pb.currentPage -1}&rows=5"aria-label="Previous"><span aria-hidden="true">«</span></a></li><%--有多少页就生成多少个li标签 使用到循环--%><c:forEach begin="1" end="${requestScope.pb.totalPage}" var="i"><%-- <li><a href="${pageContext.request.contextPath}/findeUserByPageServlet?currentPage=${i}&rows=5">${i}</a></li> <%–当前的页码–%>--%><c:if test="${pb.currentPage == i}"><li class="active"><ahref="${pageContext.request.contextPath}/findeUserByPageServlet?currentPage=${i}&rows=5">${i}</a></li> <%--当前的页码--%></c:if><c:if test="${pb.currentPage != i}"><li><a href="${pageContext.request.contextPath}/findeUserByPageServlet?currentPage=${i}&rows=5">${i}</a></li> <%--当前的页码--%></c:if></c:forEach><c:if test="${requestScope.pb.currentPage >= requestScope.pb.totalPage}"><%--下一页--%><li class="disabled"><a href="${pageContext.request.contextPath}/findeUserByPageServlet?currentPage=${requestScope.pb.currentPage +1}&rows=5"aria-label="Next"><span aria-hidden="true">»</span></a></li></c:if><c:if test="${requestScope.pb.currentPage < requestScope.pb.totalPage}"><%--下一页--%><li><a href="${pageContext.request.contextPath}/findeUserByPageServlet?currentPage=${requestScope.pb.currentPage +1}&rows=5"aria-label="Next"><span aria-hidden="true">»</span></a></li></c:if><span style="font-size: 25px;margin-left: 5px">共${requestScope.pb.totalCount}条记录，共${requestScope.pb.totalPage}页</span></ul></nav></div></body></html>
运行效果
功能六、复杂条件查询
修改页面代码
1、在FindUserByPageServlet中添加条件查询
package com.zhou.test.web;/*** @author it春和* @create -03-03 23:59*/import com.zhou.test.domain.PageBean;import com.zhou.test.domain.User;import com.zhou.test.service.UserService;import com.zhou.test.service.impl.UserServiceImpl;import javax.servlet.*;import javax.servlet.http.*;import javax.servlet.annotation.*;import java.io.IOException;import java.util.Map;@WebServlet("/findeUserByPageServlet")public class FindeUserByPageServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {request.setCharacterEncoding("utf-8");// 1、接收参数String currentPage = request.getParameter("currentPage");String rows = request.getParameter("rows");// 获取条件查询的参数Map<String, String[]> condition = request.getParameterMap();if(currentPage == null || "".equals(currentPage)){currentPage = "1";}if(rows == null || "".equals(rows)){rows = "5";}int _currentPage = Integer.parseInt(currentPage);int _rows = Integer.parseInt(rows);// 再次判断if(_currentPage <= 0){_currentPage = 1;}// 2、调用service查询UserService userService = new UserServiceImpl();PageBean<User> pb = userService.findUserByPage(_currentPage, _rows,condition);System.out.println(pb);//3.将PageBean存入requestrequest.setAttribute("pb",pb);// 将查询条件存入request域中request.setAttribute("condition",condition);//4.转发到list.jsprequest.getRequestDispatcher("/list.jsp").forward(request,response);}@Overrideprotected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doGet(request, response);}}
2、重构UserService
/*** 分页查询用户* @param currentPage 当前页* @param rows 每页显示的条数* @param condition 条件* @return 返回一个pagebean对象*/public PageBean<User> findUserByPage(int currentPage, int rows, Map<String, String[]> condition);
@Overridepublic PageBean<User> findUserByPage(int currentPage, int rows, Map<String, String[]> condition) {UserDao userDao = new UserDaoImpl();PageBean<User> userPageBean = new PageBean<>();userPageBean.setCurrentPage(currentPage);userPageBean.setRows(rows);// 查询总记录数int totalCount = userDao.findTotalCount(condition);userPageBean.setTotalCount(totalCount);// 计算总页数 总页数 = totalCount % rows == 0 ? totalCount / rows : totalCount / rows + 1int totalPage = (totalCount % rows) == 0 ? (totalCount / rows) : (totalCount / rows + 1);userPageBean.setTotalPage(totalPage);if (currentPage >= totalPage){currentPage = totalPage;}// 查询每页显示的用户数据 开始索引为 （currentPage-1） * rowsint start = (currentPage - 1) * rows;List<User> userList = userDao.findUserByPage(start, rows,condition);userPageBean.setList(userList);return userPageBean;}
3、重构UserDao
/*** 分页查询* @param strat 开始索引* @param end 一页查询多少条记录* @param condition 条件* @return 装在User的集合*/public List<User> findUserByPage(int strat, int end, Map<String, String[]> condition);
@Overridepublic int findTotalCount(Map<String, String[]> condition) {// 1、定义一个模板sqlString sql = "select count(*) from t_user where 1=1 ";StringBuilder sb = new StringBuilder(sql);// 2、遍历mapSet<String> keySet = condition.keySet();// 定义参数的集合List<Object> params = new ArrayList<>();for (String key : keySet) {// 首先排除掉分页相关的条件if ("currentPage".equals(key) || "rows".equals(key)) {continue; // 结束本次循环 继续下一次循环}// 获取valueString value = condition.get(key)[0];// 判断value是否有值if (value != null && !"".equals(value)) {// 表示value有值 那么拼接字符串sb.append(" and " + key + " like ? ");// value就是我们将要传递的参数 将value加入集合params.add("%" + value + "%");}}String new_sql = sb.toString();System.out.println(new_sql);System.out.println(params);Integer integer = template.queryForObject(new_sql, Integer.class,params.toArray()); // 传递参数return integer;}@Overridepublic List<User> findUserByPage(int strat, int end, Map<String, String[]> condition) {// 定义模板sqlString sql = "select * from t_user where 1=1 ";StringBuilder sb = new StringBuilder(sql);// 2、遍历mapSet<String> keySet = condition.keySet();// 定义参数的集合List<Object> params = new ArrayList<>();for (String key : keySet) {// 首先排除掉分页相关的条件if ("currentPage".equals(key) || "rows".equals(key)) {continue; // 结束本次循环 继续下一次循环}// 获取valueString value = condition.get(key)[0];// 判断value是否有值if (value != null && !"".equals(value)) {// 表示value有值 那么拼接字符串sb.append(" and " + key + " like ? ");// value就是我们将要传递的参数 将value加入集合params.add("%" + value + "%");}}// 添加分页查询sb.append(" limit ?,? ");// 像参数集合中添加start rowsparams.add(strat);params.add(end);System.out.println(sb.toString());System.out.println(params);List<User> users = template.query(sb.toString(), new BeanPropertyRowMapper<User>(User.class), params.toArray());return users;}
4、回显数据
在FindeUserByPageServlet中已经将条件的map集合存入了request域中
在list.jsp页面中将codition取出 设置input表单的value属性
5、测试
6、小细节
当我们点击第二页或者第三页的时候 发现会出现不安条件查询的结果数据
所以我们应该在页码的请求路径上加上条件condition
修改list.jsp
