SpringBoot请求转发的方式

概论

想要使用SpringBoot进行请求的转发，我们一共是有两大类（四种方法），一种是controller控制器转发一种是使用HttpServletRequest进行转发，这里每个方式都有两种转发方式一种内部转发一种外部转发

controller控制器转发

package com.example.requestplay.demos.web.RequestPlay1;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @author：DUOLUONIANDAI
 * @DATA：2023/07/26 11:24
 * @Title：
 */

@RestController
public class GetPlay {
    @RequestMapping("/r1")
    public String r1(){
        return "收到请求rt1";
    }
    @RequestMapping("/r2")
    public String r2(){
        return "收到请求rt2";
    }
}

package com.example.requestplay.demos.web.RequestPlay1;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @author：DUOLUONIANDAI
 * @DATA：2023/07/26 11:24
 * @Title：
 */

@Controller
public class ToGetPlay {

    @RequestMapping("/tr1")
    public String r1(){
        return "forward:/r1";
    }

    @RequestMapping("/tr2")
    public String r2(){
        return "redirect:/r2";
    }
}

切记转发不能使用RestController要不然不会被view解析会直接返回对应的字符串到页面

HttpServleRequest转发

package com.example.requestplay.demos.web.RequestPlay2;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @author：DUOLUONIANDAI
 * @DATA：2023/07/26 11:40
 * @Title：
 */

@RestController
public class GetRequest {

    @RequestMapping("/ghr1")
    public String ghr1(){
        return "收到转发的请求";
    }

    @RequestMapping("/ghr2")
    public String ghr2(){
        return "ghr2收到转发完毕";
    }
}

package com.example.requestplay.demos.web.RequestPlay2;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * @author：DUOLUONIANDAI
 * @DATA：2023/07/26 11:39
 * @Title：
 */

@RestController
public class ToRequest {

    @RequestMapping("/thr1")
    public String r1(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws ServletException, IOException {

        RequestDispatcher requestDispatcher = httpServletRequest.getRequestDispatcher("/ghr1");
        requestDispatcher.forward(httpServletRequest,httpServletResponse);

        return "转发完毕";
    }

    @RequestMapping("/thr2")
    public String r2(HttpServletResponse httpServletResponse) throws IOException {
        httpServletResponse.sendRedirect("/ghr2");
        return "转发完毕！";
    }
}

注意到底是HttpServleRequest还是HttpServleResponse，并且注意外部转发和内部转发的优缺点。