差異處
這裏顯示兩個版本的差異處。
|
java:web:resteasy:fetch_raw_message [2018/07/01 20:16] tony [ReadInterceptor & InputStreamSniffer] |
java:web:resteasy:fetch_raw_message [2023/06/25 09:48] |
||
|---|---|---|---|
| 行 1: | 行 1: | ||
| - | {{tag>resteasy}} | ||
| - | ====== How to fetch raw message after the request is failed? (working) ====== | ||
| - | ===== Problem ===== | ||
| - | RESTEasy jackson provider讓我們可以輕鬆的將第三方服務回應的json內容，轉成我們自己的物件，讓程式碼只專注於資源物件的操作；然而，第三方服務並非永遠都如你預期，它可能突然更新甚至吐出你不認得的訊息: | ||
| - | <code> | ||
| - | javax.ws.rs.ProcessingException: RESTEASY003145: Unable to find a MessageBodyReader of content-type text/html;charset=iso-8859-1 | ||
| - | </code> | ||
| - | 我有幸遇到這樣的問題，也讓我思考著該如何將原始資料記錄下來以回報第三方服務提供者。本篇文章分享可能的作法，可依照你的需求自行挑選。 | ||
| - | ===== How to resolve? ===== | ||
| - | ==== ReadInterceptor & InputStreamSniffer ==== | ||
| - | 一開始遇到這個問題時，我的想法是: 是否可以透過[[https://blog.wfyvv.com/blog/2018/03/jax-rs/|interceptor]]去處理? 我所提供的第一個方法，是註冊一個ReadInterceptor，並且wrap原始的InputStream，將讀取的內容給記錄下來。首先是ReaderInterceptor，它會從Context中取出InputStream，並將其wrap成InputStreamSniffer，代整個讀取流程執行後，可以透過getReadContent去拿到讀取的內容: | ||
| - | <code java> | ||
| - | @Provider | ||
| - | public class SnifferReadInterceptor implements ReaderInterceptor { | ||
| - | |||
| - | private InputStreamSniffer inputStreamSniffer = null; | ||
| - | |||
| - | @Override | ||
| - | public Object aroundReadFrom(ReaderInterceptorContext context) throws IOException, WebApplicationException { | ||
| - | InputStream inputStream = context.getInputStream(); | ||
| - | |||
| - | inputStreamSniffer = new InputStreamSniffer(inputStream); | ||
| - | context.setInputStream(inputStreamSniffer); | ||
| - | |||
| - | return context.proceed(); | ||
| - | } | ||
| - | |||
| - | public String getReadContent(){ | ||
| - | return inputStreamSniffer.getContent(); | ||
| - | } | ||
| - | } | ||
| - | </code> | ||
| - | InputStreamSniffer則是將讀取的動作delegate給原始的InputStream，並悄悄地記下讀取內容: | ||
| - | <code java> | ||
| - | public class InputStreamSniffer extends InputStream { | ||
| - | |||
| - | private InputStream srcInputStream; | ||
| - | private StringBuilder contentStringBuilder; | ||
| - | |||
| - | public InputStreamSniffer(InputStream inputStream){ | ||
| - | srcInputStream = inputStream; | ||
| - | contentStringBuilder = new StringBuilder(); | ||
| - | } | ||
| - | |||
| - | @Override | ||
| - | public int read() throws IOException { | ||
| - | int read_c = srcInputStream.read(); | ||
| - | contentStringBuilder.append((char)read_c); | ||
| - | return read_c; | ||
| - | } | ||
| - | // .. skip | ||
| - | </code> | ||
| - | |||
| - | |||
| - | ===== Reference ===== | ||
| - | - [[https://blog.wfyvv.com/blog/2018/03/jax-rs/|JAX-RS 2.0 简介及其过滤器与拦截器]] | ||
| - | |||
