springBoot+vue 图片上传及回显的代码实现

后端代码实现：

1.引入相关依赖

<!-- 文件上传 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
    <groupId>commons-fileupload</groupId>
    <artifactId>commons-fileupload</artifactId>
    <version>1.4</version>
</dependency>
<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.6</version>
</dependency>

2.配置文件上传相关信息

# 文件上传限制
spring.servlet.multipart.max-file-size=10MB
spring.servlet.multipart.max-request-size=10MB
spring.servlet.multipart.enabled=true

3.编写文件上传接口

@RestController
@RequestMapping("/api/file")
public class FileController {

    @PostMapping("/upload")
    public String upload(@RequestParam("file") MultipartFile file) throws IOException {
        if (file.isEmpty()) {
            return "文件为空";
        }

        String fileName = file.getOriginalFilename();
        String filePath = "D:\\temp\\";
        File dest = new File(filePath + fileName);
        file.transferTo(dest);

        return "上传成功";
    }
}

前端代码实现：

1.安装 axios 和 element-ui

npm install axios element-ui --save

2.编写文件上传组件

<template>
  <div>
    <el-upload
      class="upload-demo"
      action="/api/file/upload"
      :auto-upload="false"
      :on-change="handleChange"
    >
      <el-button slot="trigger" type="primary">选取文件</el-button>
      <el-button v-if="imageUrl" type="success" @click="handleUpload">上传到服务器</el-button>
      <div class="el-upload__tip" slot="tip">只能上传jpg/png文件，且不超过10MB</div>
    </el-upload>
    <img v-if="imageUrl" :src="imageUrl" style="max-width: 100%;">
  </div>
</template>

<script>
import axios from 'axios';
import { Message } from 'element-ui';

export default {
  data() {
    return {
      imageUrl: '',
      file: null,
    };
  },
  methods: {
    handleChange(file) {
      this.file = file.raw;
      this.imageUrl = URL.createObjectURL(this.file);
    },
    handleUpload() {
      const formData = new FormData();
      formData.append('file', this.file);

      axios.post('/api/file/upload', formData, {
        headers: {
          'Content-Type': 'multipart/form-data',
        },
      }).then(() => {
        Message.success('上传成功');
      }).catch(() => {
        Message.error('上传失败');
      });
    },
  },
};
</script>

至此，图片上传及回显的代码实现就完成了。