filter - 将新字段添加到来自 Netflix Zuul 预过滤器的请求正文

Question

我正在尝试在 Zuul 预过滤器中向请求的主体添加一个新字段。

我正在使用来自 here 的 Neflix 的 Zuul 示例项目之一，并且我的过滤器的实现与此示例中的 UppercaseRequestEntityFilter 非常相似。

我可以应用大写等转换，甚至可以完全修改请求，唯一不方便的是我无法修改长度超过原始长度的body请求的内容 body 的要求。

这是我的过滤器的实现:

@Component
public class MyRequestEntityFilter extends ZuulFilter {
    public String filterType() {
        return "pre";
    }

    public int filterOrder() {
        return 10;
    }

    public boolean shouldFilter() {
        RequestContext context = getCurrentContext();
        return true;
    }

    public Object run() {
        try {
            RequestContext context = getCurrentContext();
            InputStream in = (InputStream) context.get("requestEntity");
            if (in == null) {
                in = context.getRequest().getInputStream();
            }

            String body = StreamUtils.copyToString(in, Charset.forName("UTF-8"));

            body = body.replaceFirst("qqq", "qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq");

            // body = body.toUpperCase();

            context.set("requestEntity", new ServletInputStreamWrapper(body.getBytes("UTF-8")));
        }
        catch (IOException e) {
            rethrowRuntimeException(e);
        }
        return null;
    }
} 

这是我正在做的请求:

这是我收到的回复:

Answer 1

使用 PrefixRequestEntityFilter 的实现，我能够从 sample-zuul-examples 获得我想要的东西:

@Component
public class MyRequestEntityFilter extends ZuulFilter {
    public String filterType() {
        return "pre";
    }

    public int filterOrder() {
        return 10;
    }

    public boolean shouldFilter() {
        RequestContext context = getCurrentContext();
        return true;
    }

    public Object run() {
        try {
            RequestContext context = getCurrentContext();
            InputStream in = (InputStream) context.get("requestEntity");
            if (in == null) {
                in = context.getRequest().getInputStream();
            }

            String body = StreamUtils.copyToString(in, Charset.forName("UTF-8"));

            body = body.replaceFirst("qqq", "qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq");

            byte[] bytes = body.getBytes("UTF-8");

            context.setRequest(new HttpServletRequestWrapper(getCurrentContext().getRequest()) {
                @Override
                public ServletInputStream getInputStream() throws IOException {
                    return new ServletInputStreamWrapper(bytes);
                }

                @Override
                public int getContentLength() {
                    return bytes.length;
                }

                @Override
                public long getContentLengthLong() {
                    return bytes.length;
                }
            });

        }
        catch (IOException e) {
            rethrowRuntimeException(e);
        }
        return null;
    }
}