SpringBoot中获取当前请求的request和response

在Spring Boot中，你可以以多种方式获取当前请求的HttpServletRequest和HttpServletResponse对象。以下是几种常见的写法示例：

1. 在方法参数中声明

最常见和推荐的方式是在控制器方法的参数中直接声明HttpServletRequest和HttpServletResponse对象。Spring Boot会自动将它们注入到方法中。

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@RestController
public class MyController {

    @GetMapping("/hello1")
    public String hello1(HttpServletRequest request, HttpServletResponse response) {
        // 使用 request 对象
        String method = request.getMethod();
        String uri = request.getRequestURI();

        // 使用 response 对象
        response.setContentType("text/plain");
        response.setStatus(HttpServletResponse.SC_OK);

        return "Hello 1, Spring Boot!";
    }
}

2. 使用 @RequestMappingHandlerAdapter

你可以通过注入RequestMappingHandlerAdapter来手动获取HttpServletRequest和HttpServletResponse对象。这种方式比较灵活，但相对较少使用。

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@RestController
public class MyController {

    @Autowired
    private RequestMappingHandlerAdapter handlerAdapter;

    @GetMapping("/hello2")
    public String hello2(HttpServletRequest request, HttpServletResponse response) throws Exception {
        // 通过 handlerAdapter 获取 request 和 response 对象
        HttpServletRequest req = (HttpServletRequest) handlerAdapter.getWebBindingInitializer().getBindingContext().getModel().get("org.springframework.web.servlet.HandlerMapping.uriTemplateVariables");

        // 使用 request 对象
        String method = req.getMethod();
        String uri = req.getRequestURI();

        // 使用 response 对象
        response.setContentType("text/plain");
        response.setStatus(HttpServletResponse.SC_OK);

        return "Hello 2, Spring Boot!";
    }
}

3. 使用 ThreadLocal

另一种方式是使用ThreadLocal来存储当前的HttpServletRequest和HttpServletResponse对象，然后在需要时从ThreadLocal中获取。

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@RestController
public class MyController {

    @GetMapping("/hello3")
    public String hello3() {
        // 从 RequestContextHolder 中获取 ServletRequestAttributes
        ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();

        // 获取 HttpServletRequest 对象
        HttpServletRequest request = attributes.getRequest();
        // 获取 HttpServletResponse 对象
        HttpServletResponse response = attributes.getResponse();

        // 使用 request 对象
        String method = request.getMethod();
        String uri = request.getRequestURI();

        // 使用 response 对象
        response.setContentType("text/plain");
        response.setStatus(HttpServletResponse.SC_OK);

        return "Hello 3, Spring Boot!";
    }
}

总结

以上是在Spring Boot中常见的几种方式获取当前请求的HttpServletRequest和HttpServletResponse对象。推荐使用第一种方式，即在方法参数中声明，因为它简单直观且符合Spring Boot的最佳实践。