SSM项目实现模糊搜索、分页、删除列表数据

一、前提准备：
基本环境的配置：
https://blog.csdn.net/qq_43923042/article/details/107549680
主要用到两个bean类：User类和PageInfo类，User类是主要传递的信息，PageInfo则是将User进一步分页包装
二、编写UserDao接口

package com.zhongruan.dao;
import com.zhongruan.beans.User;
import org.apache.ibatis.annotations.Param;
import java.util.List;
public interface UserDao {
User findByUserName(String name);
List<User> findAll(@Param("start") int start,@Param("username") String username);
//    List<User> findAll();
void add(User user);
void deleteById(int id);
User selectById(int id);
void update(User user);
int getTotalCount(@Param("username") String username);
void deleteAll(@Param("ids")List<Integer> ids);
}

三、编写resource/mapper/UserMapper.xml配置文件
主要是写各种sql语句，当使用到DAO层接口时直接调用语句，这一部分比较值得一提的是SQL语句中 LIKE的灵活使用可以实现模糊搜索

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.zhongruan.dao.UserDao" >
<select id="findByUserName" parameterType="String" resultType="user">
select id,username,password  from xiaolaji where username = #{username}
</select>
<select id="findAll" resultType="user">
select * from xiaolaji
<if test="username!=null and username!=''">
where username like concat("%",#{username},"%")
</if>
limit #{start},5
</select>
<insert id="add" parameterType="user">
insert into xiaolaji (username,password) values(#{username},#{password})
</insert>
<delete id="deleteById" parameterType="int">
delete from xiaolaji where id=#{id}
</delete>
<select id="selectById" parameterType="int" resultType="user">
select * from xiaolaji where id= #{id}
</select>
<update id="update" parameterType="user">
update xiaolaji set username=#{username},password=#{password} where id=#{id}
</update>
<select id="getTotalCount" resultType="int">
select count(*) from xiaolaji
<if test="username!=null and username!= ''">
where username like concat("%",#{username},"%")
</if>
</select>
<delete id="deleteAll" parameterType="list">
delete from xiaolaji where id in
<foreach collection="ids" item="id" open="(" close=")" separator=",">
#{id}
</foreach>
</delete>
</mapper>

四、Service层的构建
先构建一个service接口，声明需要用的各种函数，再写它的实现类，此处只写实现类：

package com.zhongruan.service.Impl;
import com.zhongruan.beans.PageInfo;
import com.zhongruan.beans.User;
import com.zhongruan.dao.*;
import com.zhongruan.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class UserServiceImpl implements UserService
{
@Autowired
private UserDao userDao;
@Override
public int login(String username, String password) {
User user=userDao.findByUserName(username);
if (user!=null&&user.getPassword().equals(password))
return user.getId();
return -1;
}

@Override
public PageInfo<User> findAll(int curruntPage, String username) {
PageInfo<User> pageInfo=new PageInfo<>();
pageInfo.setSize(5);
int tc=userDao.getTotalCount(username);
pageInfo.setTotalCount(tc);
//tp总页数
int tp=tc/5+1;
pageInfo.setTotalPage(tp);
if (curruntPage<1){
pageInfo.setCurruntPage(1);
}else  if (curruntPage>tp){
pageInfo.setCurruntPage(tp);
}else {
pageInfo.setCurruntPage(curruntPage);
}
int start = (pageInfo.getCurruntPage()-1)*5;
List<User> userList=userDao.findAll(start,username);
pageInfo.setList(userList);
return pageInfo;
}

@Override
public void add(User user) {
userDao.add(user);
}

@Override
public void deleteById(int id) {
userDao.deleteById(id);
}

@Override
public User selectUserById(int id) {
return userDao.selectById(id);
}

@Override
public void update(User user) {
System.out.println(user.toString());
userDao.update(user);
}

@Override
public void deleteAll(List<Integer> ids) {
userDao.deleteAll(ids);
}

}

五、写Controller接口

package com.zhongruan.controller;
import com.zhongruan.beans.PageInfo;
import com.zhongruan.beans.Role;
import com.zhongruan.beans.User;
import com.zhongruan.service.RoleService;
import com.zhongruan.service.UserService;
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.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpSession;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

@Controller
@RequestMapping("/user")
public class UserController {
@Autowired
private UserService userService;

@Autowired
private RoleService roleService;

@RequestMapping("/login.do")
public ModelAndView login(User user,HttpSession session){
int id= userService.login(user.getUsername(),user.getPassword());
ModelAndView mv=new ModelAndView();
if (id!=-1){
List<Integer> roleIds = roleService.findRoleId(id);
session.setAttribute("roleIds",roleIds);
session.setAttribute("user",user);
mv.setViewName("main");
}

else
mv.setViewName("../failer");
return mv;
}
@RequestMapping("/findAll.do")
public ModelAndView findAll(@RequestParam(defaultValue = "1")int curruntPage, String username,
@RequestParam(defaultValue="0")int type, HttpSession session){
if (type==1){
session.setAttribute("searchName",username);
}else{
username=(String)session.getAttribute("searchName");
}
PageInfo<User> pageInfo=userService.findAll(curruntPage,username);
ModelAndView mv=new ModelAndView();
mv.addObject("pageinfo",pageInfo);
mv.setViewName("user-list");
return mv;
}
@RequestMapping("/add.do")
public String add(User user){
userService.add(user);
return "redirect:findAll.do";
}
@RequestMapping("/deleteById.do")
public String delete(int id){
userService.deleteById(id);
return "redirect:findAll.do";
}
@RequestMapping("/toUpdate.do")
public ModelAndView toUpdate(int id){
User user = userService.selectUserById(id);
ModelAndView mv=new ModelAndView();
mv.setViewName("user-update");
mv.addObject("user",user);
return mv;
}
@RequestMapping("/update.do")
public String Update(User user){
userService.update(user);
return "redirect:findAll.do";
}

@RequestMapping("/deleteAll.do")
public String deleteAll(String userList){
System.out.println("deleteAll:"+userList);
String[] str= userList.split(",");
List<Integer> ids=new ArrayList<>();
for (String i:str)
ids.add(Integer.parseInt(i));
userService.deleteAll(ids);
return "redirect:findAll.do";
}

由于界面使用的是jsp编写，有些填入的数据要跟jsp中的界面互相配合才行。
jsp在此不多展示，成果：