springboot+thymeleaf后端设置全局变量前端js接收

1. 目的：前端所有地方都可以拿到统一定义的变量，可以定义的java代码中，application.yam文件或者配置文件中

2. 第一步：在spring能够管理bean的地方添加如下代码，我这里在main启动入口下面直接添加了

   package com.ruoyi;
   
   import com.google.common.collect.Maps;
   import org.mybatis.spring.annotation.MapperScan;
   import org.springframework.boot.SpringApplication;
   import org.springframework.boot.autoconfigure.SpringBootApplication;
   import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
   import org.springframework.core.env.Environment;
   import org.springframework.web.servlet.config.annotation.EnableWebMvc;
   import org.thymeleaf.spring5.view.ThymeleafViewResolver;
   
   import javax.annotation.Resource;
   import java.util.HashMap;
   import java.util.Map;
   
   /**
    * 启动程序
    *
    * @author ruoyi
    */
   @SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})
   @MapperScan("com.ruoyi.*.mapper")
   public class RuoYiApplication {
       public static void main(String[] args) {
           // System.setProperty("spring.devtools.restart.enabled", "false");
           SpringApplication.run(RuoYiApplication.class, args);
           System.out.println("(♥◠‿◠)ﾉﾞ  DIX启动成功   ლ(´ڡ`ლ)ﾞ  \n" +
                   " .-------.       ____     __        \n" +
                   " |  _ _   \\      \\   \\   /  /    \n" +
                   " | ( ' )  |       \\  _. /  '       \n" +
                   " |(_ o _) /        _( )_ .'         \n" +
                   " | (_,_).' __  ___(_ o _)'          \n" +
                   " |  |\\ \\  |  ||   |(_,_)'         \n" +
                   " |  | \\ `'   /|   `-'  /           \n" +
                   " |  |  \\    /  \\      /           \n" +
                   " ''-'   `'-'    `-..-'              ");
       }
   
   
       @Resource
       private Environment env;
   
       @Resource
       private void configureThymeleafStaticVars(ThymeleafViewResolver viewResolver) {
           if(viewResolver != null) {
               Map<String, Object> vars = Maps.newHashMap();
               vars.put("ctx", env.getProperty("ctx"));
               viewResolver.setStaticVariables(vars);
           }
       }
   
   }
   
   
   

3. 然后到前端的代码,把这段代码放到header.html,统一加载就行了

   <script th:inline="javascript">
       const ctx = '[(${ctx})]';
       console.log(ctx)
   </script>
   

4. 我的 application.yml文件配置,添加一行变量就可以了

   #js ajax请求统一添加路径
   ctx: http://127.0.0.1:8085/