IDEA入门搭建ssm，实现分页功能和拦截器
项目原理
今天学习内容是ssm项目实现分页功能和拦截器。
1.分页功能的实现思路是通过sql语句limit来确定页面的开始数以及数量多少；
2.bean层新建pageInfo类来保存分页信息；
package com.zr.bean;
import java.util.List;
public class PageInfo {
private List list;
private int totalCount;
private int size;
private int totalPage;
private int currentPage;
public List getList() {
return list;
}
public void setList(List list) {
this.list = list;
}
public int getTotalCount() {
return totalCount;
}
public void setTotalCount(int totalCount) {
this.totalCount = totalCount;
}
public int getSize() {
return size;
}
public void setSize(int size) {
this.size = size;
}
public int getTotalPage() {
return totalPage;
}
public void setTotalPage(int totalPage) {
this.totalPage = totalPage;
}
public int getCurrentPage() {
return currentPage;
}
public void setCurrentPage(int currentPage) {
this.currentPage = currentPage;
}
@Override
public String toString() {
return "PageInfo{" +
"list=" + list +
", totalCount=" + totalCount +
", size=" + size +
", totalPage=" + totalPage +
", currentPage=" + currentPage +
'}';
}
}
3.在UserSerImpl中修改findAll()方法
@Override
public PageInfo findAll(int currentPage,String username) {
PageInfo pageInfo=new PageInfo();
int totalCount=userDao.getTotalCount(username);
pageInfo.setTotalCount(totalCount);
double d=totalCount/5.0;
int tp= (int) Math.ceil(d);
pageInfo.setTotalPage(tp);
pageInfo.setSize(5);
if(currentPage<1){
pageInfo.setCurrentPage(1);
}else if(currentPage>tp){
pageInfo.setCurrentPage(tp);
}else {
pageInfo.setCurrentPage(currentPage);
}
int start=(pageInfo.getCurrentPage()-1)*5;
List userList = userDao.findAll(start, 5,username);
pageInfo.setList(userList);
return pageInfo;
} 4.修改前端代码 user_list.jsp
${user.id}
${user.username}
${user.password}
更新
删除
添加角色
目录结构
源码
UserController
package com.zr.controller;
import com.zr.bean.PageInfo;
import com.zr.bean.User;
import com.zr.service.IUserService;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpSession;
import java.util.List;
@Controller
@RequestMapping("user")
public class UserController {
@Autowired
private IUserService userService;
@RequestMapping("login.do")
public ModelAndView login(User user,HttpSession session){
boolean flag = userService.login(user.getUsername(),user.getPassword());
ModelAndView modelAndView=new ModelAndView();
if(flag){
session.setAttribute("user",user);
modelAndView.setViewName("main");
}else {
modelAndView.setViewName("../failer");
}
return modelAndView;
}
@RequestMapping("findAll.do")
public ModelAndView findAll(@RequestParam(defaultValue = "1") int currentPage, String username,
@RequestParam(defaultValue = "0") int type,
HttpSession session){
if(type==1){
session.setAttribute("searchname",username);
}else if(type==0) {
username= (String) session.getAttribute("searchname");
}else if(type==2){
session.removeAttribute("searchname");
}
PageInfo pageInfo = userService.findAll(currentPage,username);
ModelAndView mv=new ModelAndView();
mv.setViewName("user-list");
mv.addObject("pageInfo",pageInfo);
return mv;
}
@RequestMapping("deleteById.do")
public String delete(int id){
userService.deleteById(id);
return "redirect:findAll.do";
}
@RequestMapping("add.do")
public String add(User user){
userService.add(user);
return "redirect:findAll.do";
}
@RequestMapping("toUpdate.do")
public ModelAndView toUpdate(int id){
User user=userService.selectUserById(id);
ModelAndView modelAndView=new ModelAndView();
modelAndView.addObject("user",user);
modelAndView.setViewName("user-update");
return modelAndView;
}
@RequestMapping("update.do")
public String update(User user){
userService.update(user);
return "redirect:findAll.do";
}
} IUserDao
package com.zr.dao;
import com.zr.bean.User;
import org.apache.ibatis.annotations.Param;
import java.util.List;
public interface IUserDao {
User findUserByUsername(String username);
List findAll(@Param("start") int start, @Param("size")int size,@Param("username") String username);
void deleteById(int id);
void add(User user);
User selectUserById(int id);
void update(User user);
int getTotalCount(@Param("username") String username);
} LoginFilter
package com.zr.filter;
import com.zr.bean.User;
import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
public class LoginFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
HttpServletRequest request= (HttpServletRequest) servletRequest;
HttpServletResponse response= (HttpServletResponse) servletResponse;
HttpSession session = request.getSession();
User user= (User) session.getAttribute("user");
String url=request.getRequestURL().toString();
if(user==null && url.indexOf("login.do")==-1){
response.sendRedirect("../login.jsp");
}else {
filterChain.doFilter(request,response);
}
}
@Override
public void destroy() {
}
}UserServiceImpl
import com.zr.bean.PageInfo;
import com.zr.bean.User;
import com.zr.dao.IUserDao;
import com.zr.service.IUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class UserServiceImpl implements IUserService {
@Autowired
private IUserDao userDao;
@Override
public boolean login(String username, String password) {
User user = userDao.findUserByUsername(username);
if(user!=null&&user.getPassword().equals(password)){
return true;
}
return false;
}
@Override
public PageInfo findAll(int currentPage,String username) {
PageInfo pageInfo=new PageInfo();
int totalCount=userDao.getTotalCount(username);
pageInfo.setTotalCount(totalCount);
double d=totalCount/5.0;
int tp= (int) Math.ceil(d);
pageInfo.setTotalPage(tp);
pageInfo.setSize(5);
if(currentPage<1){
pageInfo.setCurrentPage(1);
}else if(currentPage>tp){
pageInfo.setCurrentPage(tp);
}else {
pageInfo.setCurrentPage(currentPage);
}
int start=(pageInfo.getCurrentPage()-1)*5;
List userList = userDao.findAll(start, 5,username);
pageInfo.setList(userList);
return pageInfo;
}
@Override
public void deleteById(int id) {
userDao.deleteById(id);
}
@Override
public void add(User user) {
userDao.add(user);
}
@Override
public User selectUserById(int id) {
return userDao.selectUserById(id);
}
@Override
public void update(User user) {
userDao.update(user);
}
}
IUserService
package com.zr.service;
import com.zr.bean.PageInfo;
import com.zr.bean.User;
import java.util.List;
public interface IUserService {
boolean login(String username,String password);
PageInfo findAll(int currentPage,String username);
void deleteById(int id);
void add(User user);
User selectUserById(int id);
void update(User user);
} UserMapper.xml
delete from tb_user where id =#{id}
insert into tb_user(username,password) values (#{username},#{password})
update tb_user set username=#{username},password=#{password} where id =#{id}
运行结果
查询所有
查询1
翻页
