Feign httpclient文件上传问题记录

问题说明

原先项目http请求通过feign + ribbon + urlconnection 完成，考虑urlconnection频繁连接释放带来网络及cpu开销问题采用http client作为连接池，升级完后发现发现出现调用下游服务乱码、传文件 文件内容被篡改问题

处理

乱码问题

原先系统feign-core、feign-httpclient使用9.5.0 ，按GitHub issue看，这个版本并不是使用utf-8作为编码，导致中文乱码情况，鉴于项目用的版本相对较老，这边只升级到9.6.0解决了乱码问题，之前也有通过feign拦截器处理，但是这样需要判断特定的content-type进行处理，避免麻烦，open-feign强调他们的编码是utf-8，部分版本不是，可以定义为bug，既然是bug，能通过升级解决问题就直接升级了

传文件内容被篡改

有问题找GitHub，还是由于版本问题，老版本的一个bug，通过httpclient导致文件上传内容篡改，3.0.3版本修复了，早期项目使用的版本是2.0.1，有点年头，参考了下官方建议要求

Requirements

The feign-form extension depend on OpenFeign and its concrete versions:

• all feign-form releases before 3.5.0 works with OpenFeign 9.* versions;
• starting from feign-form's version 3.5.0, the module works with OpenFeign 10.1.0 versions and greater.

IMPORTANT: there is no backward compatibility and no any gurantee that the feign-form's versions after 3.5.0work with OpenFeign before 10.*. OpenFeign was refactored in 10th release, so the best approach - use the freshest OpenFeign and feign-form versions.

Notes:

• spring-cloud-openfeign uses OpenFeign 9.* till v2.0.3.RELEASE and uses 10.* after. Anyway, the dependency already has suitable feign-form version, see dependency pom, so you don't need to specify it separately;
• spring-cloud-starter-feign is a deprecated dependency and it always uses the OpenFeign's 9.* versions.

使用了如下版本pom，接口httpclient下文件上传内容被篡改问题

feign-version = 9.6.0
<dependency>
<groupId>io.github.openfeign.form</groupId>
<artifactId>feign-form</artifactId>
<version>3.4.1</version>
</dependency>
<dependency>
<groupId>io.github.openfeign.form</groupId>
<artifactId>feign-form-spring</artifactId>
<version>3.4.1</version>
</dependency>
<dependency>
<groupId>io.github.openfeign</groupId>
<artifactId>feign-httpclient</artifactId>
<version>${feign.version}</version>
</dependency>
<dependency>
<groupId>io.github.openfeign</groupId>
<artifactId>feign-core</artifactId>
<version>${feign.version}</version>
</dependency>
<dependency>
<groupId>io.github.openfeign</groupId>
<artifactId>feign-hystrix</artifactId>
<version>${feign.version}</version>
</dependency>
<dependency>
<groupId>io.github.openfeign</groupId>
<artifactId>feign-slf4j</artifactId>
<version>${feign.version}</version>
</dependency>

多附件文件上传问题

默认SpringFormEncoder只处理单文件，一个强转就完事了

@Override
public void encode (Object object, Type bodyType, RequestTemplate template) throws EncodeException {
if (!bodyType.equals(MultipartFile.class)) {
super.encode(object, bodyType, template);
return;
}
val file = (MultipartFile) object;
val data = singletonMap(file.getName(), object);
super.encode(data, MAP_STRING_WILDCARD, template);
}

我们系统文件上传支持多附件，这个需要重写下

/**
* @author yugj
* @date 2019/8/28 下午4:27.
*/
public class FeignSpringFormEncoder extends FormEncoder {
/**
* Constructor with the default Feign's encoder as a delegate.
*/
public FeignSpringFormEncoder() {
this(new Default());
}
/**
* Constructor with specified delegate encoder.
*
* @param delegate delegate encoder, if this encoder couldn't encode object.
*/
public FeignSpringFormEncoder(Encoder delegate) {
super(delegate);
MultipartFormContentProcessor processor = (MultipartFormContentProcessor) getContentProcessor(ContentType.MULTIPART);
processor.addWriter(new SpringSingleMultipartFileWriter());
processor.addWriter(new SpringManyMultipartFilesWriter());
}
@Override
public void encode(Object object, Type bodyType, RequestTemplate template) throws EncodeException {
if (bodyType.equals(MultipartFile.class)) {
MultipartFile file = (MultipartFile) object;
Map data = Collections.singletonMap(file.getName(), object);
super.encode(data, MAP_STRING_WILDCARD, template);
return;
} else if (bodyType.equals(MultipartFile[].class)) {
MultipartFile[] file = (MultipartFile[]) object;
if(file != null) {
Map data = Collections.singletonMap(file.length == 0 ? "" : "file", object);
super.encode(data, MAP_STRING_WILDCARD, template);
return;
}
}
super.encode(object, bodyType, template);
}
}

对应feignclient使用这个配置即可

@Service
@FeignClient(name = "xx-file-sv",
fallbackFactory = FileGeneralHystrixFallbackAdapter.class,
configuration = FeignSpringFormEncoder.class)
public interface IFileClient extends IFile {
}