Springboot-案例 增删改查二
准备
前端程序、后端工程（web/mybatis/mysql/lombok）、数据库
开发规范
GET：查询
POST：新增
PUT：修改
DELETE：删除
Result.java
@Data
@NoArgsConstructor
@AllArgsConstructor
public class Result {
private Integer code;//响应码： 1 成功 0 失败
private String msg;//响应信息 描述字符串
private Object data;//返回数据
public static Result success(){ //增删改 成功响应
return new Result(1,"success",null);
}
public static Result success(Object data){ //查询成功 响应
return new Result(1,"success",data);
}
public static Result error(String msg){ //失败响应
return new Result(0,msg,null);
}
}
示例1：查询 删除 增加部门
@RestController
@Slf4j
//优化请求路径
@RequestMapping("/depts")
public class DeptController {
@Autowired
private DeptService deptService;
@GetMapping
public Result list(){
log.info("查询部门信息");
List<Dept> list = deptService.list();
return Result.success(list);
}
@DeleteMapping("/{id}")
public Result delete(@PathVariable Integer id){
log.info("删除部门{}",id);
deptService.delete(id);
return Result.success();
}
/*
* 页面请求参数 @RequestBody
* */
@PostMapping
public Result add(@RequestBody Dept dept){
log.info("新增部门{}",dept);
deptService.add(dept);
return Result.success();
}
}
@Service
public class DeptServiceImpl implements DeptService {
@Autowired
private DeptMapper deptMapper;
@Override
public List<Dept> list() {
return deptMapper.list();
}
@Override
public void delete(Integer id) {
deptMapper.delete(id);
}
@Override
public void add(Dept dept) {
dept.setCreateTime(LocalDateTime.now());
dept.setUpdateTime(LocalDateTime.now());
deptMapper.add(dept);
}
}
public interface DeptService {
List<Dept> list();
void delete(Integer id);
void add(Dept dept);
}
@Mapper
public interface DeptMapper {
@Select("select * from dept")
List<Dept> list();
@Delete("delete from dept where id =#{id}")
void delete(Integer id);
@Insert("insert into dept(name,create_time,update_time) values (#{name},#{createTime},#{updateTime} )" )
void add(Dept dept);
}
示例2：员工管理
2.1分页查询（SQL语句查询）
-- 分页查询
-- 参数1:起始索引 = (页码-1)*每页需要展示的数据数
-- 参数2 : 每页展示的数据数
select * from emp limit 0,5;
select * from emp limit 5,5;
@Mapper
public interface EmpMapper {
@Select("select count(*) from emp")
public Long count();
/**
* 分页查询
* @param start
* @param pageSize
* @return
*/
@Select("select * from emp limit #{start},#{pageSize}")
public List<Emp> page(Integer start,Integer pageSize);
}
@Service
public class EmpServiceImpl implements EmpService {
@Autowired
private EmpMapper empMapper;
@Override
public PageBean page(Integer page, Integer pageSize) {
PageBean pageBean = new PageBean();
pageBean.setTotal(empMapper.count());
pageBean.setRows(empMapper.page((page-1)*pageSize,pageSize));
return pageBean;
}
}
分页插件 pageHelper
<dependency>
<groupId>com.github.pagehelpergroupId>
<artifactId>pagehelper-spring-boot-starterartifactId>
<version>1.4.3version>
dependency>
@Override
public PageBean page(Integer page, Integer pageSize) {
PageHelper.startPage(page,pageSize);
List<Emp> list = empMapper.list();
Page<Emp> p= (Page<Emp>) list;
return new PageBean(p.getTotal(),p.getResult());
}
2.2 条件分页查询员工（动态SQL）
select * from emp where username like concat('%','朱','%') and gender =1 and entrydate
between '2023-10-01' and '2023-10-20' order by update_time desc ;
@RestController
@Slf4j
public class EmpController {
@Autowired
private EmpService empService;
//分页查询 分页参数 page没传递默认1 pageSize 默认10 日期参数 前面加 @DateTimeFormat(pattern = "yyyy-MM-dd")
@GetMapping("/emps")
public Result page(@RequestParam(defaultValue = "1") Integer page , @RequestParam(defaultValue = "5")Integer pageSize,
String name, Short gender,
@DateTimeFormat(pattern = "yyyy-MM-dd") LocalDate begin,
@DateTimeFormat(pattern = "yyyy-MM-dd") LocalDate end
){
log.info("分页查询,参数{},{},{},{},{},{}",page,pageSize,name,gender,begin,end);
PageBean pageBean = empService.page(page,pageSize,name,gender,begin,end );
return Result.success(pageBean);
}
}
@Service
public class EmpServiceImpl implements EmpService {
@Autowired
private EmpMapper empMapper;
@Override
public PageBean page(Integer page, Integer pageSize, String name, Short gender, LocalDate begin, LocalDate end) {
PageHelper.startPage(page,pageSize);
List<Emp> list = empMapper.list(name, gender, begin, end);
Page<Emp> p= (Page<Emp>) list;
return new PageBean(p.getTotal(),p.getResult());
}
}
public interface EmpService {
PageBean page(Integer page, Integer pageSize ,String name, Short gender, LocalDate begin, LocalDate end);
}
@Mapper
public interface EmpMapper {
public List<Emp> list(String name, Short gender, LocalDate begin, LocalDate end);
}
xml
<select id="list" resultType="com.example.demo.pojo.Emp">
select *
from emp
<where>
<if test="name != null and name!='' ">
username like concat('%', #{name}, '%')
</if>
<if test="gender != null">
and gender = #{gender}
</if>
<if test="begin != null and end != null">
and entrydate
between #{begin} and #{end}
</if>
order by update_time desc
</where>
</select>
POST 请求错误400
[nio-8080-exec-3] .w.s.m.s.DefaultHandlerExceptionResolver : Resolved [org.springframework.web.method.annotation.MethodArgumentTypeMismatchException: Failed to convert value of type 'java.lang.String' to required type 'java.time.LocalDate'; nested exception is org.springframework.core.convert.ConversionFailedException: Failed to convert from type [java.lang.String] to type [@org.springframework.format.annotation.DateTimeFormat java.time.LocalDate] for value [2023-10-1]; nested exception is java.lang.IllegalArgumentException: Parse attempt failed for value [2023-10-1]]
注意：postman请求发送日期：严格要求yyyy-MM-dd 格式 2023-10-01
2.3 新增员工
@PostMapping
public Result save(@RequestBody Emp emp){
log.info("新增员工:{}",emp);
empService.save(emp);
return Result.success();
}
@Insert("insert into emp (username,password,gender,image,job,entrydate,dept_id,create_time,update_time) values (#{username},#{password},#{gender},#{image},#{job},#{entrydate},#{deptId},#{createTime},#{updateTime})")
void insert(Emp emp);
文件上传
DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>文件上传title>
head>
<body>
<form action="/upload" method="post" enctype="multipart/form-data">
姓名:<input type="text" name="username"><br>
年龄:<input type="text" name="age"><br>
头像:<input type="file" name="image"><br>
<input type="submit" value="提交">
form>
body>
html>
本地存储
@RestController
@Slf4j
public class UploadController {
@PostMapping("/upload")
public Result upload(String username, Integer age, MultipartFile image) throws IOException {
log.info("文件上传 {},{},{}",username,age,image);
String name = image.getOriginalFilename();//原始文件名
String s = UUID.randomUUID().toString();
image.transferTo(new File("E:\\"+s+name.substring(name.lastIndexOf("."))));
return Result.success();
}
}
在Springboot 文件上传默认单个最大文件大小为1M。需要上传大文件，配置:
#单个最大上传文件大小
spring.servlet.multipart.max-file-size=10MB
#单个请求最大上传大小（一次可上传多个）
spring.servlet.multipart.max-request-size=100MB
阿里云存储oss
依赖
<dependency>
<groupId>com.aliyun.ossgroupId>
<artifactId>aliyun-sdk-ossartifactId>
<version>3.15.1version>
dependency>
java 9.0以上
<dependency>
<groupId>javax.xml.bindgroupId>
<artifactId>jaxb-apiartifactId>
<version>2.3.1version>
dependency>
<dependency>
<groupId>javax.activationgroupId>
<artifactId>activationartifactId>
<version>1.1.1version>
dependency>
<dependency>
<groupId>org.glassfish.jaxbgroupId>
<artifactId>jaxb-runtimeartifactId>
<version>2.3.3version>
dependency>
@Component
public class AliOSSUtils {
private String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
private String accessKeyId = "";
private String accessKeySecret = "";
private String bucketName = "";
public String upload(MultipartFile file) throws IOException {
//获取上传文件输入流
InputStream inputStream = file.getInputStream();
//避免文件覆盖
String originalFilename = file.getOriginalFilename();
String fileName = UUID.randomUUID().toString()+originalFilename.substring(originalFilename.lastIndexOf("."));
OSS ossClient = new OSSClientBuilder().build(endpoint, accessKeyId,accessKeySecret);
ossClient.putObject(bucketName,fileName,inputStream);
String url = endpoint.split("//")[0]+"//"+bucketName+"."+endpoint.split("//")[1]+"/"+fileName;
ossClient.shutdown();
return url;
}
}
@Autowired
private AliOSSUtils aliOSSUtils;
@PostMapping("/upload")
public Result upload( MultipartFile image) throws IOException {
String url = aliOSSUtils.upload(image);
return Result.success(url);
}
2.4 修改员工
查找
//路径参数 id 用@PathVariable
@GetMapping("/{id}")
public Result getById(@PathVariable Integer id){
Emp emp = empService.getById(id);
return Result.success(emp);
}
@Override
public Emp getById(Integer id) {
return empMapper.getById(id);
}
Emp getById(Integer id);
@Select("select * from emp where id=#{id}")
Emp getById(Integer id);
修改
//根据id根新员工信息
@PutMapping
public Result updateById(@RequestBody Emp emp){
empService.updateById(emp);
return Result.success();
}
@Override
public void updateById(Emp emp) {
emp.setUpdateTime(LocalDateTime.now());
empMapper.updateById(emp);
}
void updateById(Emp emp);
void updateById(Emp emp);
<update id="updateById">
update emp
<set>
<if test="username != null and username !=''">
username = #{username},
if>
<if test="password != null and password !=''">
password = #{password},
if>
<if test="gender !=null ">
gender = #{gender},
if>
<if test="image != null and image !=''">
image = #{image},
if>
<if test="job!=null">
job = #{job},
if>
<if test="entrydate != null">
entrydate = #{entrydate},
if>
<if test="deptId != null">
dept_id = #{deptId},
if>
<if test="updateTime != null">
update_time = #{updateTime}
if>
set>
where id = #{id}
update>
参数配置 properties
yml配置
application.yml 或者application.yaml
server:
port: 9000
这里插入图片描述](https://img-blog.csdnimg.cn/5ae2da4c42e44a86be204497c3719ac8.png)
yml语法
#定义对象 /Map集合
user:
name: 明太祖
age: 22
# 数组 List set
hobby:
- sing
- jump
- rap
- basketball
spring properties文件替换yml
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/mybatis?useSSL=false&characterEncoding=UTF-8
spring.datasource.username=root
spring.datasource.password=1234
mybatis.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl
mybatis.configuration.map-underscore-to-camel-case=true
spring.servlet.multipart.max-file-size=10MB
spring.servlet.multipart.max-request-size=100MB
aliyun.oss.endpoint=https://oss-cn-hangzhou.aliyuncs.com
aliyun.oss.accessKeyId=
aliyun.oss.accessKeySecret=
aliyun.oss.bucketName=
spring:
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost:3306/mybatis?useSSL=false&characterEncoding=UTF-8
username: root
password: 1234
servlet:
multipart:
max-file-size: 10MB
max-request-size: 100MB
#log-impl 日志 cam 驼峰命名
mybatis:
configuration:
log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
map-underscore-to-camel-case: true
#文件上传 multipa
#自定义
aliyun:
oss:
endpoint: https://oss-cn-hangzhou.aliyuncs.com
accessKeyId:
accessKeySecret:
bucketName:
@ConfigurationProperties
@value(“${ }”)太繁琐
使用示例:
@Component
public class AliOSSUtils {
@Value("${aliyun.oss.endpoint}")
private String endpoint;
@Value("${aliyun.oss.accessKeyId}")
private String accessKeyId ;
@Value("${aliyun.oss.accessKeySecret}")
private String accessKeySecret ;
@Value("${aliyun.oss.bucketName}")
private String bucketName ;
public String upload(MultipartFile file) throws IOException {
//获取上传文件输入流
InputStream inputStream = file.getInputStream();
//避免文件覆盖
String originalFilename = file.getOriginalFilename();
String fileName = UUID.randomUUID().toString()+originalFilename.substring(originalFilename.lastIndexOf("."));
OSS ossClient = new OSSClientBuilder().build(endpoint, accessKeyId,accessKeySecret);
ossClient.putObject(bucketName,fileName,inputStream);
String url = endpoint.split("//")[0]+"//"+bucketName+"."+endpoint.split("//")[1]+"/"+fileName;
ossClient.shutdown();
return url;
}
}
@Component
public class AliOSSUtils {
@Autowired
private AliOSSProperties aliOSSProperties;
public String upload(MultipartFile file) throws IOException {
String endpoint = aliOSSProperties.getEndpoint();
String accessKeyId = aliOSSProperties.getAccessKeyId();
String accessKeySecret = aliOSSProperties.getAccessKeySecret();
String bucketName = aliOSSProperties.getBucketName();
//获取上传文件输入流
InputStream inputStream = file.getInputStream();
//避免文件覆盖
String originalFilename = file.getOriginalFilename();
String fileName = UUID.randomUUID().toString()+originalFilename.substring(originalFilename.lastIndexOf("."));
OSS ossClient = new OSSClientBuilder().build(endpoint, accessKeyId,accessKeySecret);
ossClient.putObject(bucketName,fileName,inputStream);
String url = endpoint.split("//")[0]+"//"+bucketName+"."+endpoint.split("//")[1]+"/"+fileName;
ossClient.shutdown();
return url;
}
}
@Data
@Component
@ConfigurationProperties(prefix = "aliyun.oss")
public class AliOSSProperties {
private String endpoint;
private String accessKeyId;
private String accessKeySecret;
private String bucketName;
}
警告
引入依赖
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-configuration-processorartifactId>
dependency>