文件上传
服务器搭建
云服务
LTAI5t5hEbLq6RPAc5ihjWEH
vY9VD0hh9q7TcFU2H9AP9x8FPEA8hr
配置环境变量
set OSS_ACCESS_KEY_ID=LTAI5t5hEbLq6RPAc5ihjWEH
set OSS_ACCESS_KEY_SECRET=vY9VD0hh9q7TcFU2H9AP9x8FPEA8hr
设置使其生效
setx OSS_ACCESS_KEY_ID "%OSS_ACCESS_KEY_ID%"
setx OSS_ACCESS_KEY_SECRET "%OSS_ACCESS_KEY_SECRET%"
验证是否生效
echo %OSS_ACCESS_KEY_ID%
echo %OSS_ACCESS_KEY_SECRET%
阿里云搭建相关视频在107集
package com.itheima.utils;import com.aliyun.oss.*;
import com.aliyun.oss.common.auth.CredentialsProviderFactory;
import com.aliyun.oss.common.auth.EnvironmentVariableCredentialsProvider;
import com.aliyun.oss.common.comm.SignVersion;
import org.springframework.stereotype.Component;
import java.io.ByteArrayInputStream;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.util.UUID;@Component
public class AliyunOSSOperator {private String endpoint = "https://oss-cn-beijing.aliyuncs.com";private String bucketName = "java-ai-01-david";private String region = "cn-beijing";public String upload(byte[] content, String originalFilename) throws Exception {// 从环境变量中获取访问凭证。运行本代码示例之前，请确保已设置环境变量OSS_ACCESS_KEY_ID和OSS_ACCESS_KEY_SECRET。EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();// 填写Object完整路径，例如202406/1.png。Object完整路径中不能包含Bucket名称。//获取当前系统日期的字符串,格式为 yyyy/MMString dir = LocalDate.now().format(DateTimeFormatter.ofPattern("yyyy/MM"));//生成一个新的不重复的文件名String newFileName = UUID.randomUUID() + originalFilename.substring(originalFilename.lastIndexOf("."));String objectName = dir + "/" + newFileName;// 创建OSSClient实例。官方代码ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);OSS ossClient = OSSClientBuilder.create().endpoint(endpoint).credentialsProvider(credentialsProvider).clientConfiguration(clientBuilderConfiguration).region(region).build();try {ossClient.putObject(bucketName, objectName, new ByteArrayInputStream(content));} finally {ossClient.shutdown();}return endpoint.split("//")[0] + "//" + bucketName + "." + endpoint.split("//")[1] + "/" + objectName;}}
package com.itheima.controller;import com.itheima.pojo.Result;
import com.itheima.utils.AliyunOSSOperator;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;import java.io.File;
import java.io.IOException;
import java.util.UUID;@Slf4j
@RestController
public class UploadController {
// /**
// * 本地磁盘存储，不推荐
// * @param name
// * @param age
// * @param file
// * @return
// * @throws IOException
// */
// @PostMapping("/upload")
// public Result upload(String name, Integer age, MultipartFile file) throws IOException {
// log.info("接收的参数：{},{},{}",name,age,file);
// //获取原始文件名
// String originalFilename = file.getOriginalFilename();
// //新的文件名
// String extension = originalFilename.substring(originalFilename.lastIndexOf("."));
// String newFileName = UUID.randomUUID().toString() + extension;
// //保存文件
// //file.transferTo(new File("F:/images/"+originalFilename));
// file.transferTo(new File("F:/images/"+newFileName));
// return Result.success();
// }@Autowiredprivate AliyunOSSOperator aliyunOSSOperator;@PostMapping("/upload")public Result upload(MultipartFile file) throws Exception {log.info("文件上传：{}",file.getOriginalFilename());//将文件交给OSS存储管理String url = aliyunOSSOperator.upload(file.getBytes(), file.getOriginalFilename());log.info("文件上传到OSS，url："+url);return Result.success(url);}
}
#阿里云OSS
aliyun:oss:endpoint: https://oss-cn-beijing.aliyuncs.combucketName: java-ai-01-davidregion: cn-beijing
package com.itheima.utils;import com.aliyun.oss.*;
import com.aliyun.oss.common.auth.CredentialsProviderFactory;
import com.aliyun.oss.common.auth.EnvironmentVariableCredentialsProvider;
import com.aliyun.oss.common.comm.SignVersion;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import java.io.ByteArrayInputStream;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.util.UUID;@Component
public class AliyunOSSOperator {// private String endpoint = "https://oss-cn-beijing.aliyuncs.com";
// private String bucketName = "java-ai-01-david";
// private String region = "cn-beijing";@Value("${aliyun.oss.endpoint}")private String endpoint ;@Value("${aliyun.oss.bucketName}")private String bucketName ;@Value("${aliyun.oss.region}")private String region ;public String upload(byte[] content, String originalFilename) throws Exception {// 从环境变量中获取访问凭证。运行本代码示例之前，请确保已设置环境变量OSS_ACCESS_KEY_ID和OSS_ACCESS_KEY_SECRET。EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();// 填写Object完整路径，例如202406/1.png。Object完整路径中不能包含Bucket名称。//获取当前系统日期的字符串,格式为 yyyy/MMString dir = LocalDate.now().format(DateTimeFormatter.ofPattern("yyyy/MM"));//生成一个新的不重复的文件名String newFileName = UUID.randomUUID() + originalFilename.substring(originalFilename.lastIndexOf("."));String objectName = dir + "/" + newFileName;// 创建OSSClient实例。官方代码ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);OSS ossClient = OSSClientBuilder.create().endpoint(endpoint).credentialsProvider(credentialsProvider).clientConfiguration(clientBuilderConfiguration).region(region).build();try {ossClient.putObject(bucketName, objectName, new ByteArrayInputStream(content));} finally {ossClient.shutdown();}return endpoint.split("//")[0] + "//" + bucketName + "." + endpoint.split("//")[1] + "/" + objectName;}}
package com.itheima.utils;import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;@Data
@Component
@ConfigurationProperties(prefix = "aliyun.oss")
public class AliyunOSSProperties {private String endpoint;private String bucketName;private String region;
}
package com.itheima.utils;import com.aliyun.oss.*;
import com.aliyun.oss.common.auth.CredentialsProviderFactory;
import com.aliyun.oss.common.auth.EnvironmentVariableCredentialsProvider;
import com.aliyun.oss.common.comm.SignVersion;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import java.io.ByteArrayInputStream;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.util.UUID;@Component
public class AliyunOSSOperator {// private String endpoint = "https://oss-cn-beijing.aliyuncs.com";
// private String bucketName = "java-ai-01-david";
// private String region = "cn-beijing";//方式一：提供@Value注解将属性逐一注入
// @Value("${aliyun.oss.endpoint}")
// private String endpoint ;
// @Value("${aliyun.oss.bucketName}")
// private String bucketName ;
// @Value("${aliyun.oss.region}")
// private String region ;//方式二：@Autowiredprivate AliyunOSSProperties aliyunOSSProperties;public String upload(byte[] content, String originalFilename) throws Exception {String endpoint = aliyunOSSProperties.getEndpoint();String bucketName = aliyunOSSProperties.getBucketName();String region = aliyunOSSProperties.getRegion();// 从环境变量中获取访问凭证。运行本代码示例之前，请确保已设置环境变量OSS_ACCESS_KEY_ID和OSS_ACCESS_KEY_SECRET。EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();// 填写Object完整路径，例如202406/1.png。Object完整路径中不能包含Bucket名称。//获取当前系统日期的字符串,格式为 yyyy/MMString dir = LocalDate.now().format(DateTimeFormatter.ofPattern("yyyy/MM"));//生成一个新的不重复的文件名String newFileName = UUID.randomUUID() + originalFilename.substring(originalFilename.lastIndexOf("."));String objectName = dir + "/" + newFileName;// 创建OSSClient实例。官方代码ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);OSS ossClient = OSSClientBuilder.create().endpoint(endpoint).credentialsProvider(credentialsProvider).clientConfiguration(clientBuilderConfiguration).region(region).build();try {ossClient.putObject(bucketName, objectName, new ByteArrayInputStream(content));} finally {ossClient.shutdown();}return endpoint.split("//")[0] + "//" + bucketName + "." + endpoint.split("//")[1] + "/" + objectName;}}
删除员工
@DeleteMapping
public Result delete(@RequestParam List<Integer> ids){log.info("批量删除员工：{}", ids);empService.delete(ids);return Result.success();
}
@Transactional(rollbackFor = {Exception.class})
@Override
public void delete(List<Integer> ids) {//删除员工的基本信息empMapper.deleteByIds(ids);//删除员工的工作经历信息empExprMapper.deleteByEmpIds(ids);}
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.itheima.mapper.EmpExprMapper">
<!-- 批量保存员工工作经历foreach:collection:遍历的集合item:遍历出来的元素的名字separator:每次循环之间的分隔符
--><insert id="insertBatch">insert into emp_expr(emp_id, begin, end, company, job) VALUES<foreach collection="exprList" item="expr" separator=",">(#{expr.empId},#{expr.begin},#{expr.end},#{expr.company},#{expr.job})</foreach></insert><delete id="deleteByEmpIds">delete from emp_expr where emp_id in<foreach collection="empIds" item="Id" separator="," open="(" close=")">#{Id}</foreach></delete>
</mapper>
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.itheima.mapper.EmpMapper">
<!-- 批量删除员工的基本信息--><delete id="deleteByIds">delete from emp where id in<foreach collection="ids" item="id" separator="," open="(" close=")">#{id}</foreach></delete><select id="list" resultType="com.itheima.pojo.Emp">select e.*,d.name deptName from emp e left join dept d on e.dept_id = d.id<where><if test="name != null and name != ''">e.name like concat('%',#{name},'%')</if><if test="gender != null">and e.gender = #{gender}</if><if test="begin != null and end != null">and entry_date between #{begin} and #{end}</if></where>order by e.update_time desc</select>
</mapper>
Spring 对List类型的参数，无论参数名是否一致，都必须显式添加@RequestParam注解才能完成绑定，不存在 “省略注解也能生效” 的情况。下面详细拆解原因和修正方案。
一、为什么这段代码不加注解会失效？
-
Spring 的参数绑定规则限制
Spring 的无注解自动绑定仅支持基本类型、包装类、String、数组等「简单类型」，而
List是集合容器类型，不在自动绑定的范围内。即使参数名names与前端传入的参数名完全一致，Spring 也无法识别 “将请求中的names参数封装为List<String>”，最终入参names会是null。 -
实际运行的表现
若执行这段代码，前端请求
/list?names=张三&names=李四，后端接收到的names值为null，返回结果会是List参数：null，而非预期的List参数：[张三, 李四]。
二、正确的写法（必须加@RequestParam）
想要让List<String> names正确绑定前端参数，必须显式添加@RequestParam注解，这是唯一的正确方式：java运行
@GetMapping("/list")
public String getList(@RequestParam List<String> names) {return "List参数：" + names;
}
此时前端请求/list?names=张三&names=李四，后端才能正确接收并封装为List<String>，返回List参数：[张三, 李四]。
三、容易混淆的 “例外情况”：数组类型可省略注解
如果将入参改为数组类型String[] names，则可以省略@RequestParam，因为数组属于 Spring 的「简单类型」，支持无注解自动绑定：java运行
// ✅ 数组类型：参数名一致，可省略@RequestParam，绑定正常
@GetMapping("/list")
public String getList(String[] names) {return "数组参数：" + Arrays.toString(names);
}
前端请求/list?names=张三&names=李四，会返回数组参数：[张三, 李四]，这是数组与 List 的核心区别，也是最容易产生误解的点。
修改员工
- 查询回显
- 修改数据
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.itheima.mapper.EmpMapper">
<!-- 批量删除员工的基本信息--><delete id="deleteByIds">delete from emp where id in<foreach collection="ids" item="id" separator="," open="(" close=")">#{id}</foreach></delete><select id="list" resultType="com.itheima.pojo.Emp">select e.*,d.name deptName from emp e left join dept d on e.dept_id = d.id<where><if test="name != null and name != ''">e.name like concat('%',#{name},'%')</if><if test="gender != null">and e.gender = #{gender}</if><if test="begin != null and end != null">and entry_date between #{begin} and #{end}</if></where>order by e.update_time desc</select><!-- 定义resultMap--><resultMap id="empResultMap" type="com.itheima.pojo.Emp"><id column="id" property="id"/><result column="username" property="username"/><result column="password" property="password"/><result column="name" property="name"/><result column="gender" property="gender"/><result column="phone" property="phone"/><result column="job" property="job"/><result column="salary" property="salary"/><result column="image" property="image"/><result column="entry_date" property="entryDate"/><result column="dept_id" property="deptId"/><result column="create_time" property="createTime"/><!-- 封装工作经历--><collection property="exprList" ofType="com.itheima.pojo.EmpExpr"><id column="ee_id" property="id"/><result column="ee_empid" property="empId"/><result column="ee_begin" property="begin"/><result column="ee_end" property="end"/><result column="ee_company" property="company"/><result column="ee_job" property="job"/></collection></resultMap>
<!-- 根据ID查询员工的基本信息和员工基本工作经历信息--><select id="getById" resultMap="empResultMap">selecte.*,ee.id ee_id,ee.emp_id ee_empid,ee.begin ee_begin,ee.end ee_end,ee.company ee_company,ee.job ee_jobfrom emp e left join emp_expr ee on e.id = ee.emp_idwhere e.id =#{id};</select>
</mapper>
@PutMapping
public Result update(@RequestBody Emp emp){log.info("修改员工：{}",emp);empService.update(emp);return Result.success(emp);
}
/*** 修改员工* @param emp*/
@Transactional(rollbackFor = {Exception.class})
@Override
public void update(Emp emp) {//1.根据ID修改员工的基本信息emp.setUpdateTime(LocalDateTime.now());empMapper.updateById(emp);//2.根据ID修改员工的工作经历信息//2.1先根据员工ID删除原有的工作经历empExprMapper.deleteByEmpIds(Arrays.asList(emp.getId()));//2.2再添加List<EmpExpr> exprList = emp.getExprList();if (!CollectionUtils.isEmpty(exprList)){exprList.forEach(empExpr -> {empExpr.setEmpId(emp.getId());});empExprMapper.insertBatch(exprList);}
}
优化
动态SQL
<!-- 根据ID更新员工基本工作经历信息-->
<!-- set标签：mybatis中动态标签：自动生成set关键字；会自动删除掉更新字段后多余的逗号--><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="name != null and name != ''">name = #{name},</if><if test="gender != null">gender = #{gender},</if><if test="phone != null and phone != ''">phone = #{phone},</if><if test="job != null">job = #{job},</if><if test="salary != null">salary = #{salary},</if><if test="image != null and image != ''">image = #{image},</if><if test="entryDate != null">entry_date = #{entryDate},</if><if test="deptId != null">dept_id = #{deptId},</if><if test="updateTime != null">update_time = #{updateTime}</if></set>WHERE id = #{id}</update>
动态SQL标签
：自动删掉多余逗号;自动生成set关键字 ：自动删掉and和or