实现词库热更新两种方式
1、远程词库，2、修改源码整合数据库

要求：（前提安装ik词库。下载复制到plugin，重启即可）
1、改http请求需要返回两个头部header（Last-Modified、ETag），这两个词都是字符串类型，只要一个发生变化，改插件就会去抓取新词

2、换行符\n

一分钟执行一次API

​
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
​
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
​
@RestController
@RequestMapping(value = "/extendApi")
public class ExtendController {
​
    @RequestMapping("/getThesaurus")
    public void getThesaurus(HttpServletResponse response) throws IOException {
        File file = new File("D:\\EdgeDownLoad\\elasticsearch-7.8.0-windows-x86_64\\elasticsearch-7.8.0\\plugins\\analysis-ik\\config\\ext.dic");
        FileInputStream inputStream = new FileInputStream(file);
        //缓冲
        int offset = 0;
        byte[] buffer = new byte[(int) file.length()];
        response.setHeader("Last-Modified",String.valueOf(buffer.length));
        response.setHeader("ETag",String.valueOf(buffer.length));
        while(inputStream.read(buffer, offset,(int)file.length()-1)!=-1){
​
        }
        OutputStream outputStream = response.getOutputStream();
        outputStream.write(buffer);
        outputStream.close();
        inputStream.close();
    }
}

​
配置远程词库（“D:\EdgeDownLoad\elasticsearch-7.8.0-windows-x86_64\elasticsearch-7.8.0\plugins\analysis-ik\config\IKAnalyzer.cfg.xml”）

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
<properties>
    <comment>IK Analyzer 扩展配置</comment>
    <!--用户可以在这里配置自己的扩展字典 -->
    <entry key="ext_dict">ext.dic</entry>
     <!--用户可以在这里配置自己的扩展停止词字典-->
    <entry key="ext_stopwords"></entry>
    <!--用户可以在这里配置远程扩展字典 -->
    <entry key="remote_ext_dict">http://localhost:9091/extendApi/getThesaurus</entry> 
    <!--用户可以在这里配置远程扩展停止词字典-->
    <!-- <entry key="remote_ext_stopwords">words_location</entry> -->
</properties>
​