java如何在微文件rest客户端中动态添加HTTP头？

Question

我正在开发应用程序，它使用rest客户端。rest客户端应该发送带有各种http头的rest请求。某些标题名称会动态更改。我的rest客户端应该是通用的，但我没有找到如何实现这种行为。 根据文档，您需要通过注释指定实现中的所有头名称，这不是通用的。有没有办法“破解”它并以编程方式添加HTTP头

提前谢谢

 GenericRestClient genericRestClient = null;
 Map<String, Object> appConfig = context.appConfigs();
 String baseUrl = (String) appConfig.get("restClient.baseUrl");
 path = (String) appConfig.get("restClient.path");
 try {
     genericRestClient = RestClientBuilder.newBuilder()
                .baseUri(new URI(baseUrl)).build(GenericRestClient.class);
 }catch(URISyntaxException e){
      logger.error("",e);
      throw e;
 }

Response response = genericRestClient.sendMessage(path, value);
logger.info("Status: "+response.getStatus());
logger.info("Response body: "+response.getEntity().toString());

通用rest客户端代码：

@RegisterRestClient
public interface GenericRestClient {
    @POST
    @Path("{path}")
    @Produces("application/json")
    @Consumes("application/json")
    public Response sendMessage(<here should go any map of custom headers>, @PathParam("path") String pathParam, String jsonBody);
}

Answer 1

根据spec，可以使用ClientHeadersFactory。大概是这样的：

public class CustomClientHeadersFactory implements ClientHeadersFactory {
    @Override public MultivaluedMap<String, String> update(
        MultivaluedMap<String, String> incomingHeaders,
        MultivaluedMap<String, String> clientOutgoingHeaders
    ) {
        MultivaluedMap<String, String> returnVal = new MultivaluedHashMap<>();
        returnVal.putAll(clientOutgoingHeaders);
        returnVal.putSingle("MyHeader", "generated");
        return returnVal;
    }
}

@RegisterRestClient
@RegisterClientHeaders(CustomClientHeadersFactory.class)
public interface GenericRestClient {
    ...
}

不能将值直接传递给ClientHeadersFactory；但是，如果通过JAX-RS调用您自己的服务，您可以直接访问传入请求的头。您还可以@Inject任何需要的内容。如果这仍然不够，并且您确实需要从服务调用传递内容，那么您可以使用定制的@RequestScopebean，例如：

@RequestScope
class CustomHeader {
    private String name;
    private String value;

    // getters/setters
}

public class CustomClientHeadersFactory implements ClientHeadersFactory {
    @Inject CustomHeader customHeader;

    @Override public MultivaluedMap<String, String> update(
        MultivaluedMap<String, String> incomingHeaders,
        MultivaluedMap<String, String> clientOutgoingHeaders
    ) {
        MultivaluedMap<String, String> returnVal = new MultivaluedHashMap<>();
        returnVal.putAll(clientOutgoingHeaders);
        returnVal.putSingle(customHeader.getName(), customHeader.getValue());
        return returnVal;
    }
}

class Client {
    @Inject CustomHeader customHeader;

    void call() {
        customHeader.setName("MyHeader");
        customHeader.setValue("generated");

        ...

        Response response = genericRestClient.sendMessage(path, value);
    }
}