Spring Cloud Zuul 使用 Groovy 便携 Filter

1. 首先在pom.xml中引入groovy所需的jar

   
       org.codehaus.groovy
       groovy-all
       2.5.0-beta-2
   

    

2. 在项目中编写GroovyFilter.groovy过滤器

   import com.netflix.zuul.ZuulFilter
   import com.netflix.zuul.context.RequestContext
   import com.netflix.zuul.exception.ZuulException
   import org.apache.catalina.servlet4preview.http.HttpServletRequest
   import org.springframework.cloud.netflix.zuul.filters.support.FilterConstants
   
   class GroovyFilter extends ZuulFilter{
       @Override
       String filterType() {
           return FilterConstants.PRE_TYPE
       }
   
       @Override
       int filterOrder() {
           return 5 // 过滤器优先级
       }
   
       @Override
       boolean shouldFilter() {
           return true
       }
   
       @Override
       Object run() throws ZuulException {
           HttpServletRequest request = RequestContext.currentContext.getRequest() as HttpServletRequest
           Iterator headerIt = request.getHeaderNames().iterator();
           while (headerIt.hasNext()) {
               String name = (String) headerIt.next()
               String value = request.getHeader(name)
               println("header: " + name + ":" + value)
           }
           println("This is Groovy Filter")
           return null
       }
   }

    

3. 在Application.java 启动主类中添加Groovy加载器

    @Component
       public static class GroovyRunner implements CommandLineRunner {
   
           @Override
           public void run(String... args) throws Exception {
               MonitoringHelper.initMocks();
               FilterLoader.getInstance().setCompiler(new GroovyCompiler());
               try {
                   FilterFileManager.setFilenameFilter(new GroovyFileFilter());
                   // 这里写书的是绝对路径F:\\MyWork\\IDEA\\mall-cloud\\groovy目录下
                   FilterFileManager.init(20, "F:\\MyWork\\IDEA\\mall-cloud\\groovy");
               } catch (Exception e) {
                   throw new RuntimeException();
               }
           }
       }

   编码结束，神奇的一幕即将来临。
   启动服务后：修改GroovyFilter.groovy中的输出语句，不需重启服务，精心等待一小会时间，重新发送请求，你会发现输出语句是当前修改的输出！