如何配置Spring Boot使其支持在endpoint中直接注入自定义请求头解析对象

完全可以实现，以下是两种适配不同场景的落地方案：

方案1：Spring MVC 场景（推荐，适配绝大多数Spring Web项目） #

通过自定义HandlerMethodArgumentResolver参数解析器完成自动注入，步骤如下：

1. 实现参数解析器

import org.springframework.core.MethodParameter;
import org.springframework.web.bind.support.WebDataBinderFactory;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.method.support.ModelAndViewContainer;
import java.util.Collections;
import java.util.Map;
import java.util.stream.Collectors;

public class CommonHeaderArgumentResolver implements HandlerMethodArgumentResolver {
    // 匹配需要解析的CommonHeader类型参数
    @Override
    public boolean supportsParameter(MethodParameter parameter) {
        return parameter.getParameterType().equals(CommonHeader.class);
    }

    @Override
    public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer, NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {
        // 提取所有请求头转为Map
        Map<String, String> headerMap = Collections.list(webRequest.getHeaderNames())
                .stream()
                .collect(Collectors.toMap(h -> h, webRequest::getHeader));
        // 调用已有的解析逻辑
        CommonHeader commonHeader = CommonHeader.parseCommonHeader(headerMap);
        // 在此处添加必填字段校验逻辑，校验不通过直接抛出异常即可
        if (commonHeader.getCallerId() == null || commonHeader.getCallerId().isBlank()) {
            throw new IllegalArgumentException("请求头x-caller-id不能为空");
        }
        // 其他字段校验逻辑同理
        return commonHeader;
    }
}

2. 注册解析器到Spring MVC配置

import org.springframework.context.annotation.Configuration;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import java.util.List;

@Configuration
public class WebConfig implements WebMvcConfigurer {
    @Override
    public void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) {
        resolvers.add(new CommonHeaderArgumentResolver());
    }
}

配置完成后即可直接使用你期望的接口写法，Spring会自动完成请求头解析、校验、对象注入。

方案2：Jersey（JAX-RS）场景 #

如果项目使用Jersey作为REST框架（原生支持@Path注解），可通过自定义Factory实现：

1. 实现CommonHeader生成工厂

import org.glassfish.hk2.api.Factory;
import javax.servlet.http.HttpServletRequest;
import javax.inject.Inject;
import java.util.Collections;
import java.util.Map;
import java.util.stream.Collectors;

public class CommonHeaderFactory implements Factory<CommonHeader> {
    private final HttpServletRequest request;

    @Inject
    public CommonHeaderFactory(HttpServletRequest request) {
        this.request = request;
    }

    @Override
    public CommonHeader provide() {
        Map<String, String> headerMap = Collections.list(request.getHeaderNames())
                .stream()
                .collect(Collectors.toMap(h -> h, request::getHeader));
        CommonHeader commonHeader = CommonHeader.parseCommonHeader(headerMap);
        // 在此处添加必填字段校验逻辑
        return commonHeader;
    }

    @Override
    public void dispose(CommonHeader instance) {
        // 无清理需求可留空
    }
}

2. 注册到Jersey配置

import org.glassfish.hk2.utilities.binding.AbstractBinder;
import org.glassfish.jersey.process.internal.RequestScoped;
import org.glassfish.jersey.server.ResourceConfig;
import org.springframework.context.annotation.Configuration;

@Configuration
public class JerseyConfig extends ResourceConfig {
    public JerseyConfig() {
        packages("你的接口类所在包路径");
        register(new AbstractBinder() {
            @Override
            protected void configure() {
                bindFactory(CommonHeaderFactory.class)
                        .to(CommonHeader.class)
                        .in(RequestScoped.class);
            }
        });
    }
}

使用时在参数前加@Context注解即可：

@Path("/columnConfigs")
Response getColumnConfig(@Context CommonHeader commonHeader) {
    // 直接使用解析好的对象即可
}

内容的提问来源于stack exchange，提问作者yurii.pitomets