本章概要
- 准备工作
- 功能实现
- 前后联调
4.1 准备工作
- 数据库脚本
CREATE TABLE schedule (
id INT NOT NULL AUTO_INCREMENT,
title VARCHAR(255) NOT NULL,
completed BOOLEAN NOT NULL,
PRIMARY KEY (id)
);
INSERT INTO schedule (title, completed)
VALUES
('学习java', true),
('学习Python', false),
('学习C++', true),
('学习JavaScript', false),
('学习HTML5', true),
('学习CSS3', false),
('学习Vue.js', true),
('学习React', false),
('学习Angular', true),
('学习Node.js', false),
('学习Express', true),
('学习Koa', false),
('学习MongoDB', true),
('学习MySQL', false),
('学习Redis', true),
('学习Git', false),
('学习Docker', true),
('学习Kubernetes', false),
('学习AWS', true),
('学习Azure', false);
- 准备 pojo
包：com.atguigu.pojo
/**
* projectName: com.atguigu.pojo
*
* description: 任务实体类
*/
@Data
public class Schedule {
private Integer id;
private String title;
private Boolean completed;
}
- 准备 R
包： com.atguigu.utils
**
* projectName: com.atguigu.utils
*
* description: 返回结果类
*/
public class R {
private int code = 200; //200成功状态码
private boolean flag = true; //返回状态
private Object data; //返回具体数据
public static R ok(Object data){
R r = new R();
r.data = data;
return r;
}
public static R fail(Object data){
R r = new R();
r.code = 500; //错误码
r.flag = false; //错误状态
r.data = data;
return r;
}
public int getCode() {
return code;
}
public void setCode(int code) {
this.code = code;
}
public boolean isFlag() {
return flag;
}
public void setFlag(boolean flag) {
this.flag = flag;
}
public Object getData() {
return data;
}
public void setData(Object data) {
this.data = data;
}
}
- 准备 PageBean
包： com.atguigu.utils
@Data
@NoArgsConstructor
@AllArgsConstructor
public class PageBean<T> {
private int currentPage; // 当前页码
private int pageSize; // 每页显示的数据量
private long total; // 总数据条数
private List<T> data; // 当前页的数据集合
}
4.2 功能实现
- 分页查询
- controller
/*
@CrossOrigin 注释在带注释的控制器方法上启用跨源请求
*/
@CrossOrigin
@RequestMapping("schedule")
@RestController
public class ScheduleController
{
@Autowired
private ScheduleService scheduleService;
@GetMapping("/{pageSize}/{currentPage}")
public R showList(@PathVariable(name = "pageSize") int pageSize, @PathVariable(name = "currentPage") int currentPage){
PageBean<Schedule> pageBean = scheduleService.findByPage(pageSize,currentPage);
return R.ok(pageBean);
}
}
- service
@Slf4j
@Service
public class ScheduleServiceImpl implements ScheduleService {
@Autowired
private ScheduleMapper scheduleMapper;
/**
* 分页数据查询,返回分页pageBean
*
* @param pageSize
* @param currentPage
* @return
*/
@Override
public PageBean<Schedule> findByPage(int pageSize, int currentPage) {
//1.设置分页参数
PageHelper.startPage(currentPage,pageSize);
//2.数据库查询
List<Schedule> list = scheduleMapper.queryPage();
//3.结果获取
PageInfo<Schedule> pageInfo = new PageInfo<>(list);
//4.pageBean封装
PageBean<Schedule> pageBean = new PageBean<>(pageInfo.getPageNum(),pageInfo.getPageSize(),pageInfo.getTotal(),pageInfo.getList());
log.info("分页查询结果:{}",pageBean);
return pageBean;
}
}
- mapper
mapper 接口
public interface ScheduleMapper {
List<Schedule> queryPage();
}
mapper.xml 文件
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"https://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!-- namespace等于mapper接口类的全限定名,这样实现对应 -->
<mapper namespace="com.atguigu.mapper.ScheduleMapper">
<select id="queryPage" resultType="schedule">
select * from schedule
</select>
</mapper>
- 计划添加
- controller
@PostMapping
public R saveSchedule(@RequestBody Schedule schedule){
scheduleService.saveSchedule(schedule);
return R.ok(null);
}
- service
/**
* 保存学习计划
*
* @param schedule
*/
@Override
public void saveSchedule(Schedule schedule) {
scheduleMapper.insert(schedule);
}
- mapper
mapper 接口
void insert(Schedule schedule);
mapper.xml 文件
<insert id="insert">
insert into schedule (title, completed)
values
(#{title}, #{completed});
</insert>
- 计划删除
- controller
@DeleteMapping("/{id}")
public R removeSchedule(@PathVariable Integer id){
scheduleService.removeById(id);
return R.ok(null);
}
- service
/**
* 移除学习计划
*
* @param id
*/
@Override
public void removeById(Integer id) {
scheduleMapper.delete(id);
}
- mapper
mapper 接口
void delete(Integer id);
mapper.xml 文件
<delete id="delete">
delete from schedule where id = #{id}
</delete>
- 计划修改
- controller
@PutMapping
public R changeSchedule(@RequestBody Schedule schedule){
scheduleService.updateSchedule(schedule);
return R.ok(null);
}
- service
/**
* 更新学习计划
*
* @param schedule
*/
@Override
public void updateSchedule(Schedule schedule) {
scheduleMapper.update(schedule);
}
- mapper
mapper 接口
void update(Schedule schedule);
mapper.xml 文件
<update id="update">
update schedule set title = #{title} , completed = #{completed}
where id = #{id}
</update>
4.3 前后联调
- 后台项目根路径设计
- 启动测试即可
