java实现前端文档预览 前端实现word预览

最近做的项目要求实现预览word, pdf，png等文件功能，pdf以及png都很简单，轻松百度搞定，但是word预览研究了好久，所以特此记录分享。

前端实现预览word分为两种，一种是上传前预览（也就是前端使用input或者组件等选择文件后直接预览，此时还没有上传给后端，我定义为纯前端预览），一种是上传后预览（就是文档已经上传到后端，通过后端给的文件流实现预览）

一、先说第一种的实现方式:

首先下载安装docx-preview，引入

npm install xlsx docx-preview --save

import { defaultOptions, renderAsync } from "docx-preview";

var docxx = require("docx-preview");

我这里使用的是element ui 上传组件

<el-upload
      class="upload-demo"
      action=""
      :http-request="myUpload"
      :show-file-list="false"
      >
      <span class = "uploadEnclosure">上传附件</span>
    </el-upload>

选择文件以后

myUpload(content){
      console.log(content);
      const downUrl = URL.createObjectURL(content.file)
      const a = document.createElement('a');
      this.$refs.selectFileNameBox.innerHTML = "";
      this.$refs.selectFileNameBox.append(a);
      a.innerHTML = content.file.name;
      a.href = downUrl
      a.download = content.file.name;
      a.target = '_blank';
      const addTypeArray = content.file.name.split(".");
      const addType = addTypeArray[addTypeArray.length - 1];
      console.log(addType);
      
      this.uploadFileName = content.file.name;
      this.uploadFileObj = content.file;
      if (addType === "pdf") {
        const url = URL.createObjectURL(content.file);
        console.log(url);
        this.xzbjPreviewIframeSrc = url;
        this.xzbjIframeIsShow = true;
        this.xzbjDialogPreviewDiv = false;
        this.xzbjPreviewImgUrl = "";
        this.xzbjDocPreviewFlag = false;
       
        this.previewBoxStyle = "height:400px;position: relative;overflow:hidden;"
        
      }
      else if(addType === "doc" || addType === "docx" || addType === "word"){
        console.log("word文件预览")
        this.xzbjPreviewImgUrl = "";
        this.xzbjPreviewIframeSrc = "";
        this.xzbjDialogPreviewDiv = false;
        this.xzbjDocPreviewFlag = true;
        this.xzbjIframeIsShow = false;

        // 将file转为buffer
        let fr = new FileReader();
        fr.readAsArrayBuffer(content.file);
        fr.addEventListener("loadend",(e) => {
            console.log("loadend---->", e)
            let buffer = e.target.result;
            this.docxRender(buffer);
        },false);
       

        
       
      }
      //".rar, .zip, .doc, .docx, .xls, .txt, .pdf, .jpg,  .png, .jpeg,"
      else if (["png", "jpg", "jpeg","bmp"].includes(addType)) {
        this.xzbjPreviewIframeSrc = "";
        this.xzbjIframeIsShow = false;
        this.xzbjDocPreviewFlag = false;
        this.imgPreview(content.file);
        
        this.previewBoxStyle = "height:400px;position: relative;overflow:auto;"
        
      } else if (addType === "rar" || addType === "zip" || addType === "7z") {
        this.filePreviewInfo = "请下载附件进行查看"
        this.xzbjPreviewImgUrl = "";
        this.xzbjPreviewIframeSrc = "";
        this.xzbjDocPreviewFlag = false;
        this.xzbjDialogPreviewDiv = true;
        this.$message({
          message: "该文件类型暂不支持预览",
          type: "warning",
        });
        return false;
      }else{
        this.filePreviewInfo = "该文件类型暂不支持预览"
        this.xzbjPreviewIframeSrc = "";
        this.xzbjIframeIsShow = false;
        this.xzbjDialogPreviewDiv = true;
        this.xzbjPreviewImgUrl = "";
        this.xzbjDocPreviewFlag = false;
        this.$message({
          message: "请仅允许上传后缀为pdf、doc、docx、word、jpg、png、bmp、rar、zip、7z的附件",
          type: "warning",
        });
      }
    }

// 渲染docx
    docxRender(buffer) {
      let bodyContainer = document.getElementById("demoDocContainer");
      renderAsync(
          buffer, // Blob | ArrayBuffer | Uint8Array, 可以是 JSZip.loadAsync 支持的任何类型
          bodyContainer, // HTMLElement 渲染文档内容的元素,
          null, // HTMLElement, 用于呈现文档样式、数字、字体的元素。如果为 null，则将使用 bodyContainer。
          this.docxOptions // 配置
      ).then(res => {
          console.log("res---->", res)
      })
    },

下面是图片预览核心代码

imgPreview(file) {
      // 看支持不支持FileReader
      if (!file || !window.FileReader) return;
      // console.log(/^image/.test(file.type), "---/^image/.test(file.type)")
      if (/^image/.test(file.type)) {
        // 创建一个reader
        let reader = new FileReader();
        // 将图片将转成 base64 格式
        reader.readAsDataURL(file);
        // 读取成功后的回调
        reader.onload = ({ target }) => {
          this.xzbjDialogPreviewDiv = false;
          this.xzbjPreviewImgUrl = target.result; //将img转化为二进制数据
          // console.log("target:", target);

        };
      }
    },

这样就实现了纯前端预览word功能

二、接下来实现 配合后端预览word

根据后端返回的流预览word

request({
    method: "get",
    url: "/notice/noticeFileView",
    responseType: 'blob',
    params:{
    id:row.id
    },
    headers: {
    "Content-Type": 'application/json'
    },
    }).then(res=>{
    console.log(res,"---文件预览");
    
    if(row.suffix.includes("pdf")){
    this.previewPdfFn(res);
    // let blob = new Blob([res],{
    //   type: 'application/pdf'
    // })
    // let url = window.URL.createObjectURL(blob);
    this.xqPreviewImgUrl =  "";
    this.xqPreviewPdfUrl = this.previewPdfFn(res);
    this.xqPdfPreviewFlag = true; 
    this.xqDocPreviewFlag = false;
    this.xqPerviewStyle = "height:600px;position: relative;overflow:hidden"
    }else if(row.suffix.includes("docx") || row.suffix.includes("doc")|| row.suffix.includes("word")){
    console.log("预览word")
    this.xqDocPreviewFlag = true;
    let blob = new Blob([res],{
      type: 'application/pdf'
    })
    this.$nextTick(()=>{
      console.log(this.$refs.xqDocContainer,"---this.$refs.xqDocContainer")
      docxx.renderAsync(blob, this.$refs.xqDocContainer)
    })
    
    } else if (row.suffix === ".rar" || row.suffix === ".zip" || row.suffix === "7z") {
    this.xqDocPreviewFlag = false;
    this.xzbjPreviewImgUrl = "";
    this.xzbjPreviewIframeSrc = "";
    this.$message({
      message: "该文件类型暂不支持预览",
      type: "warning",
    });
      return false;
    }else if([".png", ".jpg", ".jpeg",".bmp"].includes(row.suffix)){
    let blob = new Blob([res],{
      type: 'application/pdf'
    })
    console.log(blob,"---blob")
    let url = window.URL.createObjectURL(blob);
    this.xqPreviewImgUrl =  url; 
    this.xqPdfPreviewFlag = false; 
    this.xqDocPreviewFlag = false;
    this.xqPreviewPdfUrl = "";
    this.xqPerviewStyle = "height:600px;position: relative;overflow:auto"
    }
    
    this.xqDialogPreviewDiv = false;
    }).catch(err=>{
    console.log(err,"--文件预览失败")
    })

完毕

最后是一个好友赠送的组件

<template>
  <div class="docx-preview-wrap">
    <h4>
      <input type="file" id="file" accept=".docx"  @change="getFile"/>
    </h4>
    <div id="bodyContainer"></div>
  </div>
</template>

<script>
import { defaultOptions, renderAsync } from "docx-preview";
console.log(defaultOptions);
export default {
  name: 'DocxPreview',
  data () {
    return {
      docxOptions: {
        className: "kaimo-docx-666", // string：默认和文档样式类的类名/前缀
        inWrapper:  true, // boolean：启用围绕文档内容的包装器渲染
        ignoreWidth: false, // boolean：禁用页面的渲染宽度
        ignoreHeight: false, // boolean：禁止渲染页面高度
        ignoreFonts: false, // boolean：禁用字体渲染
        breakPages: true, // boolean：在分页符上启用分页
        ignoreLastRenderedPageBreak: true, // boolean：在 lastRenderedPageBreak 元素上禁用分页
        experimental: false, // boolean：启用实验功能（制表符停止计算）
        trimXmlDeclaration: true, // boolean：如果为true，解析前会从 xml 文档中移除 xml 声明
        useBase64URL: false, // boolean：如果为true，图片、字体等会转为base 64 URL，否则使用URL.createObjectURL
        useMathMLPolyfill: false, // boolean：包括用于 chrome、edge 等的 MathML polyfill。
        showChanges: false, // boolean：启用文档更改的实验性渲染（插入/删除）
        debug: false, // boolean：启用额外的日志记录
      }
    };
  },
  methods: {
    getFile(){
      this.handlePreview()
    },
    handlePreview() {
      let file = document.getElementById("file").files[0];
      console.log(file);
      // 将file转为buffer
      let fr = new FileReader();
      fr.readAsArrayBuffer(file);
      fr.addEventListener("loadend",(e) => {
        console.log("loadend---->", e)
        let buffer = e.target.result;
        this.docxRender(buffer);
      },false);
    },
    // 渲染docx
    docxRender(buffer) {
      let bodyContainer = document.getElementById("bodyContainer");
      renderAsync(
        buffer, // Blob | ArrayBuffer | Uint8Array, 可以是 JSZip.loadAsync 支持的任何类型
        bodyContainer, // HTMLElement 渲染文档内容的元素,
        null, // HTMLElement, 用于呈现文档样式、数字、字体的元素。如果为 null，则将使用 bodyContainer。
        this.docxOptions // 配置
      ).then(res => {
        console.log("res---->", res)
      })
    }
  },
};
</script>

结束啦，每天进步一点点，早日成为大神。啦啦啦