前后端联调
JavaWenb开发
pom.xml 文件 配置
4.0.0 org.springframework.boot spring-boot-starter-parent 2.7.5 com.itheima tlias-web-management 0.0.1-SNAPSHOT tlias-web-management Demo project for Spring Boot 1.8 org.springframework.boot spring-boot-starter-web org.mybatis.spring.boot mybatis-spring-boot-starter 2.2.2 com.mysql mysql-connector-j runtime org.projectlombok lombok true org.springframework.boot spring-boot-starter-test test org.springframework.boot spring-boot-maven-plugin org.projectlombok lombok
链接数据库 和 驼峰命名
application.propertoen 文件配置
#驱动类名称 spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver #数据库连接的url spring.datasource.url=jdbc:mysql://localhost:3306/mybatis #连接数据库的用户名 spring.datasource.username=root #连接数据库的密码 spring.datasource.password=123456 #配置mybatis的日志, 指定输出到控制台 mybatis.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl #开启mybatis的驼峰命名自动映射开关 a_column ------> aCloumn mybatis.configuration.map-underscore-to-camel-case=true
Controller 层
处理前端请求的数据
package com.itheima.controller;
import com.itheima.pojo.Dept;
import com.itheima.pojo.Result;
import com.itheima.service.DeptService;
import lombok.extern.slf4j.Slf4j;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import java.util.List;
/**
* 部门管理Controller
*/
@Slf4j
@RestController
public class DeptController {
//固定代码 也可也用注解 @Slf4j private static Logger log=LoggerFactory.getLogger(DeptController.class);
// private static Logger log=LoggerFactory.getLogger(DeptController.class);
// @RequestMapping(value = "/depts",method = RequestMethod.GET) //指定请求方式get
@Autowired
private DeptService deptService;
@GetMapping("/depts")
public Result list(){
log.info("查询全部部门数据");
//调用Service
List deptList= deptService.list();
return Result.success(deptList);
}
}
service 层
服务处理逻辑调用操作
服务层接口
package com.itheima.service;
import com.itheima.pojo.Dept;
import java.util.List;
/**
* 部门管理
*/
public interface DeptService {
/*
*查询全部员工数据
* @return
* */
List list();
}
服务层实类
package com.itheima.service.impl;
import com.itheima.mapper.DeptMapper;
import com.itheima.pojo.Dept;
import com.itheima.service.DeptService;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class DeptServiceImpl implements DeptService {
@Autowired
private DeptMapper deptMapper;
@Override
public List list() {
return deptMapper.lidt();
}
//部门管理
}
数据库调用（mybatis）跟数据库链接层
package com.itheima.mapper;
import com.itheima.pojo.Dept;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
import java.util.List;
/**
* 部门管理
*/
@Mapper
public interface DeptMapper {
//查询前部部门数据
@Select("select * from tlias.dept")
List lidt();
}
实体类
package com.itheima.pojo;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import java.time.LocalDateTime;
/**
* 部门实体类
*/
@Data
@NoArgsConstructor
@AllArgsConstructor
public class Dept {
private Integer id; //ID
private String name; //部门名称
private LocalDateTime createTime; //创建时间
private LocalDateTime updateTime; //修改时间
}
返回状态码
package com.itheima.pojo;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@NoArgsConstructor
@AllArgsConstructor
public class Result {
private Integer code;//响应码，1 代表成功; 0 代表失败
private String msg; //响应信息 描述字符串
private Object data; //返回的数据
//增删改 成功响应
public static Result success(){
return new Result(1,"success",null);
}
//查询 成功响应
public static Result success(Object data){
return new Result(1,"success",data);
}
//失败响应
public static Result error(String msg){
return new Result(0,msg,null);
}
}
报错
报错代码
Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.binding.BindingException: Parameter 'start' not found. Available parameters are [arg0, pageSize, param1, param2]] with root cause@Select("select * from emp limit #{start},#{pageSize}")
public List page(@Param("start") Integer start,@Param("pageSize")Integer pageSize ); 
com.github.pagehelper
pagehelper-spring-boot-starter
1.4.6
@Override
public PageBean page(Integer page, Integer pageSize) {
// 1 分页查询
PageHelper.startPage(page, pageSize);
// 2 执行查询
List empList = empMaqqer.list();
Page p= (Page)empList;
// 3 封装pageBean 对象
PageBean pageBean=new PageBean(p.getTotal(),p.getResult());
return pageBean;
} 
文件上传
application.properties 文件名
阿里云oss
