<template>
  <div class="upload-file">
    <el-upload
        :multiple="multiple"
        :accept="accept.join(',')"
        :action="uploadFileUrl"
        :before-upload="handleBeforeUpload"
        :file-list="fileList"
        :limit="limit"
        :on-error="handleUploadError"
        :on-exceed="handleExceed"
        :on-success="handleUploadSuccess"
        :show-file-list="false"
        :data="data"
        :headers="headers"
        class="upload-file-uploader"
        ref="fileUpload"
    >
      <!-- 上傳按鈕 -->
      <el-button size="mini" type="primary">選取文件</el-button>
      <template v-if="multiple"> （按住Ctrl鍵多選）</template>
      <!-- 上傳提示 -->
      <div class="el-upload__tip" slot="tip" v-if="showTip && fileList.length<=0">
        請上傳
        <template v-if="limit"> 最多 <b style="color: #f56c6c">{{ limit }}個</b></template>
        <template v-if="fileSize"> 大小不超過 <b style="color: #f56c6c">{{ fileSize }}MB</b></template>
        <template v-if="fileType"> 格式為 <b style="color: #f56c6c">{{ fileType.join("/") }}</b></template>
        的文件
      </div>
    </el-upload>

    <!-- 文件列表 -->
    <transition-group class="upload-file-list el-upload-list el-upload-list--text" name="el-fade-in-linear" tag="ul" height="485">
      <li v-for="(file, index) in fileList" :key="file.uid || index "
          class="el-upload-list__item ele-upload-list__item-content">
        <el-link :href="file.url" rel="external nofollow"  :underline="false" target="_blank">
          <span class="el-icon-document"> {{ file.name }} </span>
        </el-link>
        <div class="ele-upload-list__item-content-action">
          <el-link :underline="false" @click="handleDelete(index)" type="danger" style="width: 50px">刪除</el-link>
        </div>
      </li>
    </transition-group>
  </div>
</template>

<script>
import {getToken} from "@/utils/auth";

export default {
  name: "FileUpload",
  props: {
    // 是否可多選
    multiple: {
      type: Boolean,
      default: true,
    },
    // 值
    value: [String, Object, Array],
    // 數(shù)量限制
    limit: {
      type: Number,
      default: 5,
    },
    // 大小限制(MB)
    fileSize: {
      type: Number,
      default: 5,
    },
    // 文件類型, 例如['png', 'jpg', 'jpeg']
    fileType: {
      type: Array,
      default: () => ["doc", "xls", "xlsx", "ppt", "txt", "pdf"],
    },
    accept: {
      type: Array,
      default: () => [".doc", ".xls", ".xlsx", ".ppt", ".txt", ".pdf"],
    },
    // 是否顯示提示
    isShowTip: {
      type: Boolean,
      default: true
    },
    // 是否重命名
    rename: {
      type: Boolean,
      default: false
    }
  },
  data() {
    return {
      number: 0,
      uploadList: [],
      uploadFileUrl: process.env.VUE_APP_BASE_API + "/file/upload", // 上傳文件服務(wù)器地址
      headers: {
        Authorization: "Bearer " + getToken(),
      },
      fileList: [],
      data: {}
    };
  },
  watch: {
    value: {
      handler(val) {
        if (val) {
          let temp = 1;
          // 首先將值轉(zhuǎn)為數(shù)組
          const list = Array.isArray(val) ? val : this.value.split(',');
          // 然后將數(shù)組轉(zhuǎn)為對象數(shù)組
          this.fileList = list.map(item => {
            if (typeof item === "string") {
              item = {name: item.name, url: item.url};
            }
            item.uid = item.uid || new Date().getTime() + temp++;
            return item;
          });
        } else {
          this.fileList = [];
          return [];
        }
      },
      deep: true,
      immediate: true
    },
    rename: {
      handler(val) {
        this.data = {rename: val}
        console.info(this.data)
      },
      deep: true,
      immediate: true
    }
  },
  computed: {
    // 是否顯示提示
    showTip() {
      return this.isShowTip && (this.fileType || this.fileSize);
    },
  },
  methods: {
    // 上傳前校檢格式和大小
    handleBeforeUpload(file) {
      // 校檢文件類型
      if (this.fileType) {
        const fileName = file.name.split('.');
        const fileExt = fileName[fileName.length - 1];
        const isTypeOk = this.fileType.indexOf(fileExt) >= 0;
        if (!isTypeOk) {
          this.$modal.msgError(`文件格式不正確, 請上傳${this.fileType.join("/")}格式文件!`);
          return false;
        }
      }
      // 校檢文件大小
      if (this.fileSize) {
        const isLt = file.size / 1024 / 1024 < this.fileSize;
        if (!isLt) {
          this.$modal.msgError(`上傳文件大小不能超過 ${this.fileSize} MB!`);
          return false;
        }
      }
      this.$modal.loading("正在上傳文件，請稍候...");
      this.number++;
      return true;
    },
    // 文件個數(shù)超出
    handleExceed() {
      this.$modal.msgError(`上傳文件數(shù)量不能超過 ${this.limit} 個!`);
    },
    // 上傳失敗
    handleUploadError(err) {
      this.$modal.msgError("上傳文件失敗，請重試");
      this.$modal.closeLoading()
    },
    // 上傳成功回調(diào)
    handleUploadSuccess(res, file) {
      if (res.code === 200) {
        this.uploadList.push({name: res.data.name, url: res.data.url});
        this.uploadedSuccessfully();
      } else {
        this.number--;
        this.$modal.closeLoading();
        this.$modal.msgError(res.msg);
        this.$refs.fileUpload.handleRemove(file);
        this.uploadedSuccessfully();
      }
    },
    // 刪除文件
    handleDelete(index) {
      this.fileList.splice(index, 1);
      this.$emit("input", this.listToString(this.fileList));
    },
    // 上傳結(jié)束處理
    uploadedSuccessfully() {
      if (this.number > 0 && this.uploadList.length === this.number) {
        this.fileList = this.fileList.concat(this.uploadList);
        this.uploadList = [];
        this.number = 0;
        this.$emit("input", this.listToString(this.fileList));
        this.$modal.closeLoading();
      }
    },
    // 獲取文件名稱
    getFileName(name) {
      if (name.lastIndexOf("/") > -1) {
        return name.slice(name.lastIndexOf("/") + 1);
      } else {
        return "";
      }
    },
    // 對象轉(zhuǎn)成指定字符串分隔
    listToString(list, separator) {
      let strs = "";
      separator = separator || ",";
      for (let i in list) {
        strs += list[i].url + separator;
      }
      return strs != '' ? strs.substr(0, strs.length - 1) : '';
    }
  }
};
</script>

<style scoped lang="scss">
.upload-file-uploader {
  margin-bottom: 5px;
}

.upload-file-list {
  max-height: 420px;
  overflow-y: auto;
}

.upload-file-list .el-upload-list__item {
  border: 1px solid #e4e7ed;
  line-height: 2;
  margin-bottom: 10px;
  position: relative;
}

.upload-file-list .ele-upload-list__item-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: inherit;
}

.ele-upload-list__item-content-action .el-link {
  margin-right: 10px;
}
</style>

<template>
  <div class="app-container">
	<el-dialog title="附件上傳" :visible.sync="open" width="700px" append-to-body>
      <el-form ref="form" :model="form" :rules="rules" label-width="100px">        
        <el-form-item label="重命名附件" prop="rename">
          <el-radio-group v-model="form.rename">
            <el-radio :label="false">否</el-radio>
            <el-radio :label="true">是</el-radio>
          </el-radio-group>
        </el-form-item>
        <el-form-item label="上傳附件" prop="file" class="is-required">
        	<!-- 文件大小最多20M，數(shù)量最多20個 -->
          <file-upload ref="upload" :fileType="fileType" :accept="accept" :fileSize="20" :limit="20" :value="form.files" :rename="form.rename"/>
        </el-form-item>
      </el-form>
      <div slot="footer" class="dialog-footer">
        <el-button type="primary" @click="submitForm">確 定</el-button>
        <el-button @click="cancel">取 消</el-button>
      </div>
    </el-dialog>
  </div>
</template>

<script>
import { add } from "@/api/xxx"; // 請求后臺的接口封裝
import FileUpload from "@/components/FileUpload";
export default {
   name: "demo",
   components: {
    FileUpload
   },
   data() {
    return {
      // 自定義允許上傳的文件格式，也可以使用組件里面定義的默認格式
      fileType: ['png','jpg','jpeg','gif'],
      accept: ['.png','.jpg','.jpeg','.gif'],
      // 表單參數(shù)
      form: {
        // 是否重命名
        rename: false,
        files: []
      },
      // 表單校驗
      rules: {
     	files: [{type: 'array', required: true, message: "附件不能為空", trigger: "blur"}]
 	  }
    }
   },
   methods: {
   	/** 提交按鈕 */
    submitForm: function () {
        this.$refs["form"].validate(valid => {
            if (valid) {
                this.form.files = this.$refs.upload.fileList
                if (!Array.isArray(this.form.files) || this.form.files.length <= 0) {
                    this.$alert("請上傳附件");
                    return false;
                }
                console.info(this.form)
                add(this.form).then(() => {
                    this.$modal.msgSuccess("操作成功");
                    this.open = false;
                });
            }
        });
    },            
  	...
  }
}
</script>

/**
 * 文件上傳請求
 */
@PostMapping("/upload")
public Result upload(MultipartFile file, @RequestParam(required = false) Boolean rename) {
    try {
        SysFile sysFile = ossService.upload(file, rename);
        return Result.success(sysFile);
    } catch (Exception e) {
        log.error("上傳文件失敗", e);
        return Result.fail(e.getMessage());
    }
}

/**
 * 文件上傳請求
 */
@Override
public SysFile upload(MultipartFile file, Boolean rename) throws IOException {
    // 獲取文件名
    String fileName = file.getOriginalFilename();
    if (rename != null && rename) {
        // 重命名
        Long fileFlag = new SnowFlakeGenerator().nextId();
        fileName = fileFlag + "." + FileTypeUtils.getExtension(file);
    }
    String uri = String.format("file/%s", fileName);

    // 上傳到文件服務(wù)
    byte[] bytes = file.getBytes();

    // 上傳并返回訪問地址
    if (!this.upload(uri, bytes)) {
        throw new ServerErrorException("上傳失敗");
    }

    String filePath = String.format("%s/%s", "阿里云OSS地址", uri);
    SysFile sysFile = new SysFile();
    sysFile.setName(fileName);
    sysFile.setUrl(filePath);
    return sysFile;
}

private Boolean upload(String fileId, byte[] bytes) {
   InputStream in = null;
   try {
       in = new ByteArrayInputStream(bytes);
       return this.upload(fileId, in);
   } finally {
       if (in != null) {
           try {
               in.close();
           } catch (IOException e) {
           }
       }
   }
}

private Boolean upload(String key, InputStream in) {
    OSSClient client = getOSSClient();
    try {
        ObjectMetadata objectMetadata = null;
        //文本文件特殊處理
        if (key.endsWith(".txt")) {
            objectMetadata = new ObjectMetadata();
            // 設(shè)置content type
            objectMetadata.setContentType("txt/plain;charset=utf-8");
        }
        PutObjectResult result = client.putObject(config.getBucketName(), key, in, objectMetadata);
        ResponseMessage response = result.getResponse();
        log.info("Oss upload result:{}", response.isSuccessful());
        return response.isSuccessful();
    } catch (OSSException oe) {
        log.error(oe.getErrorMessage());
        return false;
    } catch (ClientException ce) {
        log.error(ce.getErrorMessage());
        return false;
    } finally {
        client.shutdown();
    }
}

private OSSClient getOSSClient() {
   // config--阿里云oss的配置信息，略
   return (OSSClient) new OSSClientBuilder().build(config.getEndPoint(), config.getKeyId(), config.getSecret());
}

<!-- Aliyun oss -->
<dependency>
  <groupId>com.aliyun.oss</groupId>
  <artifactId>aliyun-sdk-oss</artifactId>
  <version>3.10.2</version>
</dependency>