rs的服务中的java限制输出有效负载响应

ozxc1zmp  于 2021-07-09  发布在  Java
关注(0)|答案(1)|浏览(380)

我使用cxf/spring构建了多个jax-rs服务。我想控制所有服务的输出有效负载响应大小。为了简单起见,假设任何服务中的api都不应该返回超过500个字符的json响应负载,我想在一个地方控制它,而不是依赖单个服务来满足这个要求(我们已经在所有服务所依赖的自定义框架/基本组件中内置了其他特性。
我尝试过用jax-rs实现这个 WriterInterceptor , ContainerResponseFilter 和cxf的 Phase Interceptor ,但这些方法似乎都不能完全满足我的要求。关于我目前所做工作的更多细节:
选项1:(writerneceptor)在重写的方法中,我获取输出流并将缓存的最大大小设置为500。当我调用在响应负载中返回超过500个字符的api时,我得到一个 HTTP 400 错误的请求状态,但响应正文包含整个json负载。

@Provider
public class ResponsePayloadInterceptor implements WriterInterceptor {
    private static final Logger LOGGER = LoggerFactory.getLogger(ResponsePayloadInterceptor.class);

    @Override
    public void aroundWriteTo(WriterInterceptorContext context) throws IOException, WebApplicationException {
        final OutputStream outputStream = context.getOutputStream();

        CacheAndWriteOutputStream cacheAndWriteOutputStream = new CacheAndWriteOutputStream(outputStream);
        cacheAndWriteOutputStream.setMaxSize(500);
        context.setOutputStream(cacheAndWriteOutputStream);

        context.proceed();
    }
}

选项2a:(cxf phase inteceptor)在重写的方法中,我从输出流中获取字符串形式的响应,并检查其大小。如果大于500,我将创建一个新的响应对象,只包含过多的数据,并在消息中设置它。即使响应大于500个字符,我也会得到一个 HTTP 200 整个json的ok状态。只有当我用相位作为 POST_MARSHAL 或者在稍后的阶段,我可以获得json响应并检查它的长度,但此时响应已经流式传输到客户端。

@Provider
public class ResponsePayloadInterceptor extends AbstractPhaseInterceptor<Message> {
    private static final Logger LOGGER = LoggerFactory.getLogger(ResponsePayloadInterceptor.class);

    public ResponsePayloadInterceptor() {
        super(Phase.POST_MARSHAL);
    }

    @Override
    public void handleMessage(Message message) throws Fault {
        LOGGER.info("handleMessage() - Response intercepted");
        try {
            OutputStream outputStream = message.getContent(OutputStream.class);
...
            CachedOutputStream cachedOutputStream = (CachedOutputStream) outputStream;
            String responseBody = IOUtils.toString(cachedOutputStream.getInputStream(), "UTF-8");
...
            LOGGER.info("handleMessage() - Response: {}", responseBody);
            LOGGER.info("handleMessage() - Response Length: {}", responseBody.length());
            if (responseBody.length() > 500) {
                Response response = Response.status(Response.Status.BAD_REQUEST)
                                            .entity("Too much data").build();
                message.getExchange().put(Response.class, response);
            }
        } catch (IOException e) {
            LOGGER.error("handleMessage() - Error");
            e.printStackTrace();
        }
    }
}

选项2b:(cxf phase interceptor)同上,但只更改if块的内容。如果响应长度大于500,我将创建一个新的输出流,其中字符串的数据太多,并在消息中设置它。但是如果响应负载大于500个字符,我仍然会得到一个 HTTP 200 具有无效json响应(整个json+附加文本)的ok状态,即响应如下所示: [{"data":"", ...}, {...}]Too much data (文本“too much data”附加到json中)

if (responseBody.length() > 500) {
            InputStream inputStream = new ByteArrayInputStream("Too much data".getBytes("UTF-8"));
            outputStream.flush();
            IOUtils.copy(inputStream, outputStream);

            OutputStream out = new CachedOutputStream();
            out.write("Too much data".getBytes("UTF-8"));
            message.setContent(OutputStream.class, out);
        }

选项3:(containerresponsefilter)使用containerresponsefilter,我添加了一个 Content-Length 值为500的响应标头。如果响应长度大于500,则得到 HTTP 200 ok状态,json响应无效(截断为500个字符)。如果响应长度<500,仍然得到 HTTP 200 正常状态,但客户机等待服务器返回更多数据(如预期的那样)并超时,这不是理想的解决方案。

@Provider
public class ResponsePayloadFilter implements ContainerResponseFilter {
    private static final Logger LOGGER = LoggerFactory.getLogger(ResponsePayloadFilter.class);

    @Override
    public void filter(ContainerRequestContext requestContext, ContainerResponseContext responseContext) throws IOException {
        LOGGER.info("filter() - Response intercepted");
        CachedOutputStream cos = (CachedOutputStream) responseContext.getEntityStream();
        StringBuilder responsePayload = new StringBuilder();
        ByteArrayOutputStream out = new ByteArrayOutputStream();

        if (cos.getInputStream().available() > 0) {
            IOUtils.copy(cos.getInputStream(), out);
            byte[] responseEntity = out.toByteArray();
            responsePayload.append(new String(responseEntity));
        }

        LOGGER.info("filter() - Content: {}", responsePayload.toString());
        responseContext.getHeaders().add("Content-Length", "500");
    }
}

关于如何调整上述方法以获得所需内容或任何其他不同指针,有什么建议吗?

5tmbdcev

5tmbdcev1#

我通过这个答案的帮助部分地解决了这个问题。我之所以这么说,部分是因为我成功地控制了有效负载,但不是响应状态码。理想情况下,如果响应长度大于500并且我修改了消息内容,我希望发送一个不同的响应状态代码(除了200ok)。但这是一个足够好的解决方案,我可以在这一点上继续。如果我也知道如何更新状态码,我会回来更新这个答案。

import org.apache.commons.io.IOUtils;
import org.apache.cxf.interceptor.Fault;
import org.apache.cxf.io.CachedOutputStream;
import org.apache.cxf.message.Message;
import org.apache.cxf.phase.AbstractPhaseInterceptor;
import org.apache.cxf.phase.Phase;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class ResponsePayloadInterceptor extends AbstractPhaseInterceptor<Message> {
    private static final Logger LOGGER = LoggerFactory.getLogger(ResponsePayloadInterceptor.class);

    public ResponsePayloadInterceptor() {
        super(Phase.PRE_STREAM);
    }

    @Override
    public void handleMessage(Message message) throws Fault {
        LOGGER.info("handleMessage() - Response intercepted");
        try {
            OutputStream outputStream = message.getContent(OutputStream.class);
            CachedOutputStream cachedOutputStream = new CachedOutputStream();
            message.setContent(OutputStream.class, cachedOutputStream);

            message.getInterceptorChain().doIntercept(message);

            cachedOutputStream.flush();
            cachedOutputStream.close();

            CachedOutputStream newCachedOutputStream = (CachedOutputStream) message.getContent(OutputStream.class);
            String currentResponse = IOUtils.toString(newCachedOutputStream.getInputStream(), "UTF-8");
            newCachedOutputStream.flush();
            newCachedOutputStream.close();

            if (currentResponse != null) {
                LOGGER.info("handleMessage() - Response: {}", currentResponse);
                LOGGER.info("handleMessage() - Response Length: {}", currentResponse.length());

                if (currentResponse.length() > 500) {
                    InputStream replaceInputStream = IOUtils.toInputStream("{\"message\":\"Too much data\"}", "UTF-8");

                    IOUtils.copy(replaceInputStream, outputStream);
                    replaceInputStream.close();

                    message.setContent(OutputStream.class, outputStream);
                    outputStream.flush();
                    outputStream.close();
                } else {
                    InputStream replaceInputStream = IOUtils.toInputStream(currentResponse, "UTF-8");

                    IOUtils.copy(replaceInputStream, outputStream);
                    replaceInputStream.close();

                    message.setContent(OutputStream.class, outputStream);
                    outputStream.flush();
                    outputStream.close();
                }
            }
        } catch (IOException e) {
            LOGGER.error("handleMessage() - Error", e);
            throw new RuntimeException(e);
        }
    }

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