vue-pdf预览（以二进制格式存储在数据库中的文件）

前言

使用​​vue-pdf​​插件预览数据库中以二进制存储的pdf文件

之前写的一篇是: vue-pdf查看本地pdf文件及打印乱码问题处理

后端文件以流的方式返回

@GetMapping(value="/download/{pid}")
  @ApiOperation(value = "责任书下载", httpMethod = "GET", notes = "责任书下载")
  public void download(
      HttpServletResponse response,
      HttpServletRequest request,
      @ApiParam(name="pid",value="文件ID", required = true)@PathVariable(value = "pid", required = false) String pid)throws Exception {
      if(StringUtils.isNotBlank(pid)){
        SeAttach seAttach =seAttachManager.getByPaperId(pid);
        if(null != seAttach){
          String fileName = seAttach.getFileName();
          byte[] data = seAttach.getFileContent();
          response.setContentType("application/x-download");
          if (System.getProperty("file.encoding").equals("GBK")) {
            response.setHeader("Content-Disposition", "attachment;filename=\"" + new String(fileName.getBytes(), "ISO-8859-1") + "\"");
          } else {
            response.setHeader("Content-Disposition", "attachment;filename=\"" + URLEncoder.encode(fileName, "utf-8") + "\"");
          }
            OutputStream os = null;
          try {
            os = response.getOutputStream();
            os.write(data);
            os.flush();
          } catch (IOException e) {
            e.printStackTrace();
          }finally {
            if (os != null) {
              os.close();
            }
          }
        }
      }
  }

前台处理blob流文件转化为url

handleSee(index, row) {
      let that = this;
      that.fileId = row.pid;// 当前行数据id
      that.$store
        .dispatch("hse/previewSePapers", row.pid)
        .then(response => {
          const xhr = new XMLHttpRequest();
          const dataParams = JSON.parse(sessionStorage.currentUser); // sessionStorage中那当前用户信息
          console.log("dataPram",dataParams)
          xhr.open("get", response.request.responseURL);// 请求的url
          xhr.setRequestHeader("Authorization", "Bearer " + dataParams.token);// 携带token访问 
          xhr.responseType = "blob";// blob类型
          xhr.onload = function() {
            if (this.status === 200) {
              const blob = this.response;
              const url = createObjectURL(blob);
              // 将转化后 url 赋值给 vue-pdf 插件
              that.src = url;
              that.$refs.pdfSearch.handleOpen();
            }
          };
          xhr.send(null);
        })
        .catch(e => {
          that.$message.error("文件查看失败", e);
        });
    }

pdf插件代码

<Pdf ref="pdfSearch" :src="src" :fileId="fileId" />

<template>
  <el-dialog
    :visible.sync="pdfDialog"
    :close-on-click-modal="false"
    :show-close="false"
    width="900px"
    top="52px"
  >
    <div class="pdf" v-show="fileType == 'pdf'">
      <p class="arrow">
        <!-- 上一页 -->
        <span
          @click="changePdfPage(0)"
          class="currentPage"
          :class="{ grey: currentPage == 1 }"
          >上一页&nbsp;&nbsp;</span
        >
        <span style="color: #8c8e92;">{{ currentPage }} / {{ pageCount }}</span>
        <!-- 下一页 -->
        <span
          @click="changePdfPage(1)"
          class="currentPage"
          :class="{ grey: currentPage == pageCount }"
          >&nbsp;&nbsp;下一页</span
        >&nbsp;&nbsp;&nbsp;&nbsp;<el-button
          icon="el-icon-download"
          @click="download()"
          type="primary"
          size="mini"
          >下载</el-button
        >
        <span
          style="float :right;padding-right:40px;font-size: 20px;color: #8c8e92;cursor: pointer;"
          @click="close"
          ><i class="el-icon-close"></i
        ></span>
      </p>
        <pdf
        :src="src"
        :page="currentPage"
        @num-pages="pageCount = $event"
        @page-loaded="currentPage = $event"
        @loaded="loadPdfHandler"
      ></pdf>
    </div>
  </el-dialog>
</template>

<script>
import pdf from "vue-pdf";
export default {
  name: "attachPreview",
  components: { pdf },
  props: ["src", "fileId"],
  data() {
    return {
      filesProps: {
        label: "originName"
      },
      pdfDialog: false,
      currentPage: 0, // pdf文件页码
      pageCount: 0, // pdf文件总页数
      fileType: "pdf" // 文件类型
    };
  },
  methods: {
    // 改变PDF页码,val传过来区分上一页下一页的值,0上一页,1下一页
    changePdfPage(val) {
      if (val === 0 && this.currentPage > 1) {
        this.currentPage--;
      }
      if (val === 1 && this.currentPage < this.pageCount) {
        this.currentPage++;
      }
    },
    // pdf加载时
    loadPdfHandler() {
      this.currentPage = 1; // 加载的时候先加载第一页
    },
    handleOpen() {
      this.pdfDialog = true;
    },
    //关闭弹框
    close() {
      this.pdfDialog = false;
    },
    //附件下载
    download() {
      this.$store
        .dispatch("hse/downloadSePapers", this.fileId)
        .then(() => {
          this.$message("下载成功");
        })
        .catch(e => {
          this.$message.error("文件下载失败", e);
        });
    }
  }
};
</script>

<style lang="stylus">
.currentPage {
    cursor: pointer;
    color: #8c8e92;
}

.currentPage:hover {
    color: #2761ff;
}
.arrow{
    position: fixed;
    top: 0px;
    left :0px;
    z-index: 2;
    width: 100%;
    background-color: #191919;
    padding: 12px 0;
    margin: 0;
    text-align :center;
}
>>>.el-dialog__body {
    color: #606266;
    font-size: 14px;
    padding:0;
}
</style>

效果

数据库中对应的文件