后端返回二进制文件流，前端vue实现在线预览

首先后端的接口返回的只要二进制文件流，不要其他东西，我之前有别的字段，二进制流就得转成字符串返给前端，前端就还要再把字符串转成二进制流，没必要


import axios from 'axios'

export  const view=(url,body,params)=>{
  // let token = getTokens()
  // let queryParams = {docTemplate:'policy'}
  // Object.assign(queryParams, params)
  return axios({
    method: 'post',
    url: `${url}`,
    data: params,
    query: params,
    headers:{
      'Content-Type':"application/json;charset=UTF-8"
    },
    responseType: "blob"
  })

}
export  const img=(url,body,params)=>{
  // let token = getTokens()
  // let queryParams = {docTemplate:'policy'}
  // Object.assign(queryParams, params)
  return axios({
    method: 'post',
    url: `${url}`,
    data: params,
    query: params,
    headers:{
      'Content-Type':"application/json;charset=UTF-8"
    },
    responseType: "arraybuffer"//这是图片的返回类型
  })

}

这是封装axios，请求方法（post为例）↑↑↑↑

 import {view,img} from '@/assets/js/axios.js'//在需要用的.vue文件引入

pdf的话利用pdf.js插件↓↓↓↓↓

 await view('/document/viewDocument','',{ docID:data.docID,docTemplate:this.Type}).then(res=>{
                console.log(res)

                var blob = new Blob([res.data], {
                  type: 'application/pdf'})//这个是Content-Typele的type类型（https://tool.oschina.net/commons）
                console.log('blob=======')//
                console.log(blob)
                let fileURL= URL.createObjectURL(blob)
                let url=encodeURIComponent(fileURL)
                console.log(fileURL)//blob:http://localhost:8080/20a92c23-9734-4cea-8d6b-cff2e2a6e46b
                console.log(url)//blob%3Ahttp%3A%2F%2Flocalhost%3A8080%2F20a92c23-9734-4cea-8d6b-cff2e2a6e46b
                this.src = `http://pekbjdwdcs010:8098/pdf/web/viewer.html?file=${url}`;

                //
              }
            )

图片的话↓↓↓↓↓

await img('/document/viewDocument','',{ docID:data.docID,docTemplate:this.Type}).then(res=>{
                console.log(res)
              var url='data:image/png;base64,' + btoa(new Uint8Array(res.data).reduce((data, key) => data + String.fromCharCode(key), ''))
              // var url=`data:image/png;base64,${data.docStream}`
              this.src=url
              console.log(url)
              }
            )