起因：
用 element-ui 时，本人是没有安装其它环境，而是直接用链接引入，这个带来的问题是，每次打开网页都很慢，于是想本地化，但是发现只是下载两个引入的 js 和 css 是不够的，很多功能会无法使用，打开 DevTools 发现是还有别的资源本地没有。
再次前往官网，找到下载页面，结果发现并没有给直接的下载链接。。没办法了，自己写个脚本来下载。最后成功离线化。
下载后在 html 中引入：
<!--<link rel="stylesheet" href="https://unpkg.com/element-ui/lib/theme-chalk/index.css">-->
<link rel="stylesheet" href="element-ui/lib/theme-chalk/index.css" rel="external nofollow" >
<!--<script src="https://unpkg.com/element-ui/lib/index.js"></script>-->
<script src="element-ui/lib/index.js"></script>
下载脚本：
临时起意做的，代码里面可能会有些瑕疵，但是不影响使用，本人已经成功下载并使用。
路径可以自己更改，注意不要从 Windows 资源管理器复制，Linux 系统当我没说。
package com.ycr;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
public class Main {
static String fileP = "C:\\Users\\YCR\\Desktop\\element-ui\\"; // 不要从资源管理器复制，有的字符会有问题，导致无法创建文件
static String urlP = "https://unpkg.com/browse/element-ui@2.12.0/";
static String urlF = "https://unpkg.com/element-ui@2.12.0/";
public static void main(String[] args){
try {
GetPage("");
} catch (Exception e) {
e.printStackTrace();
}
}
static void GetPage(String after) throws Exception {
System.out.println(urlP + after);
new File(fileP + after).mkdir();
HttpURLConnection http = (HttpURLConnection) (new URL(urlP + after)).openConnection();
http.setRequestMethod("GET");
http.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3562.0 Safari/537.36");
http.connect();
if(http.getResponseCode() == 200) {
InputStream inputStream = http.getInputStream();
byte [] buffer = new byte[1024];
ArrayList<byte []> byteList = new ArrayList<>();
ArrayList<Integer> byteLength = new ArrayList<>();
int length;
int totalLength = 0;
while( (length = inputStream.read(buffer)) != -1 ) {
byteList.add(buffer);
byteLength.add(length);
totalLength += length;
buffer = new byte[1024];
}
http.disconnect();
byte [] all;
all = new byte[totalLength];
totalLength = 0;
while(byteList.size() != 0) {
System.arraycopy(byteList.get(0), 0, all, totalLength, byteLength.get(0));
totalLength += byteLength.get(0);
byteList.remove(0);
byteLength.remove(0);
}
String content = new String(all, StandardCharsets.UTF_8);
all = null;
content = content.split("tbody")[1];
String [] us = content.split("href=\"");
for(int i = 1; i < us.length; i ++) {
String href = us[i].split("\"", 2)[0];
if(href.equals("../")) {
continue;
}
if(href.charAt(href.length() - 1) == '/') {
GetPage(after + href);
} else {
GetFile(after + href);
}
}
} else {
GetPage(after);
}
}
static void GetFile(String url) throws Exception{
System.out.println(url);
HttpURLConnection http;
http = (HttpURLConnection) (new URL(urlF + url)).openConnection();
http.setRequestMethod("GET");
http.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3562.0 Safari/537.36");
http.connect();
if(http.getResponseCode() == 200) {
InputStream inputStream = http.getInputStream();
byte [] buffer = new byte[1024];
ArrayList<byte []> byteList = new ArrayList<>();
ArrayList<Integer> byteLength = new ArrayList<>();
int length;
int totalLength = 0;
while( (length = inputStream.read(buffer)) != -1 ) {
byteList.add(buffer);
byteLength.add(length);
totalLength += length;
buffer = new byte[1024];
}
http.disconnect();
byte [] all;
all = new byte[totalLength];
totalLength = 0;
while(byteList.size() != 0) {
System.arraycopy(byteList.get(0), 0, all, totalLength, byteLength.get(0));
totalLength += byteLength.get(0);
byteList.remove(0);
byteLength.remove(0);
}
File f = new File(fileP + url.replaceAll("/", "\\\\"));
f.createNewFile();
FileOutputStream fos = new FileOutputStream(f, false);
fos.write(all);
fos.flush();
fos.close();
} else {
GetFile(url);
}
}
}