InterceptingClientHttpRequest中的循

先上源码

@Override

public ClientHttpResponse execute(HttpRequest request,byte[]body)throws IOException {

    if (this.iterator.hasNext()) {

        ClientHttpRequestInterceptor nextInterceptor =this.iterator.next();

        return nextInterceptor.intercept(request,body,this);

    }

    else {

        HttpMethod method =request.getMethod();

        Assert.state(method !=null,"No standard HTTP method");

        ClientHttpRequest delegate =requestFactory.createRequest(request.getURI(),method);

        request.getHeaders().forEach((key,value) ->delegate.getHeaders().addAll(key,value));

        if (body.length >0) {

            if (delegate instanceof StreamingHttpOutputMessage) {

                StreamingHttpOutputMessage streamingOutputMessage = (StreamingHttpOutputMessage)delegate;

                streamingOutputMessage.setBody(outputStream ->StreamUtils.copy(body,outputStream));

        }

            else {

                StreamUtils.copy(body,delegate.getBody());

        }

    }

    return delegate.execute();

}

}

当iterator.hasNext()为true时,execute()方法会遍历iterator来进行额外的设置 (也就是你所定义的拦截器中的操作),就像下面的例子一样:

@Bean

  public ClientHttpRequestInterceptor requestInterceptor(AppParams params) {

      return (request,body,execution) -> {

      HttpHeaders headers =request.getHeaders();

      headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);

      headers.add(HttpHeaders.COOKIE,"JSESSIONID=" +JSESSIONID);

      return execution.execute(request,body);

};

}

当上面的方法执行到 return execution.execute(request,body)时将会再次进入最开始的execute()方法,继续判断iterator.hasNext()是否为true,若不为true,则进入else中的代码