EOFException: \n not found: limit=0 content和java.net.ProtocolException: unexpected end of stream问题处理

问题说明：项目中有一个需求，需要在请求处理成功后，获取响应数据，修改业务错误时响应的信息。于是我在filter中包装了ServletResponse改写了body数据。服务端没有报错。结果客户端请求就出现了该错误。客户端使用的OKhttp发起的请求。用原始ServletResponse和包装后的ResponseWrapper报的错不一样。

报错信息如下：

com.xxx.acc.openapi.client.exception.AccValidException: unexpected end of stream at com.xxx.acc.openapi.client.util.CommonUtils.readAsBytes(CommonUtils.java:183) at com.xxx.acc.openapi.client.util.CommonUtils.readAsString(CommonUtils.java:203) at com.xxx.acc.openapi.client.util.CommonUtils.readAsJSON(CommonUtils.java:216) at com.xxx.acc.openapi.client.Client.doRequest(Client.java:622) at com.xxx.acc.openapi.client.Client.callApi(Client.java:661) at com.xxx.acc.openapi.api.AccClient.request(AccClient.java:64) at com.xxx.acc.open.apidoc.test.DemoAccClientUtils.request(DemoAccClientUtils.java:114) at com.xxx.acc.open.apidoc.test.DemoAccClientUtils.requestBody(DemoAccClientUtils.java:74) at com.xxx.acc.open.apidoc.test.Demo2.main(Demo2.java:49) Caused by: java.net.ProtocolException: unexpected end of stream at okhttp3.internal.http1.Http1ExchangeCodec$FixedLengthSource.read(Http1ExchangeCodec.java:430) at okhttp3.internal.connection.Exchange$ResponseBodySource.read(Exchange.java:286) at okio.RealBufferedSource$1.read(RealBufferedSource.java:447) at java.io.InputStream.read(InputStream.java:101) at com.xxx.acc.openapi.client.util.CommonUtils.readAsBytes(CommonUtils.java:175) ... 8 more

通过debug客户端OKhttp代码，发现如下代码会导致报错

try {
……..
bytesReceived = newBytesReceived;
if (newBytesReceived == contentLength) {
complete(null);
} return read;
} catch (IOException e) {
throw complete(e);
}

由此判定，当response的请求头contentLength参数值与客户端获取body数据的值不同时会报该错误。

解决方法：后端在响应数据时，根据响应数据长度，重新设置response.contentLength值即可

servletResponse.setContentLength(resData.getBytes(StandardCharsets.UTF_8).length);