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Java中如何使用Response重定向

更新時(shí)間：2020年07月12日 11:55:51 作者：持續(xù)更新，2天一篇

這篇文章主要介紹了Java中如何使用Response重定向，文中通過示例代碼介紹的非常詳細(xì)，對大家的學(xué)習(xí)或者工作具有一定的參考學(xué)習(xí)價(jià)值，需要的朋友們下面隨著小編來一起學(xué)習(xí)學(xué)習(xí)吧

直接來，ResponseDemo1代碼，get請求到post請求，重定向到ResponseDemo2

我的虛擬目錄為

ResponseDemo1代碼，302是重定向狀態(tài)碼，Http狀態(tài)碼大全

package com.lingaolu.response;
 
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import java.io.IOException;
 
/**
 * @author 林高祿
 * @create 2020-07-10-15:24
 */
@WebServlet("/responseDemo1")
public class ResponseDemo1 extends HttpServlet {
 @Override
 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  System.out.println("responseDemo1進(jìn)來了......");
  // 設(shè)置狀態(tài)碼為302
  response.setStatus(302);
  // 動態(tài)獲取虛擬目錄，以后修改虛擬目錄的時(shí)候就不用了修改代碼
  String contextPath = request.getContextPath();
  // 設(shè)置響應(yīng)頭location
  response.setHeader("location",contextPath+"/responseDemo2");
 }
 
 @Override
 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  this.doPost(request,response);
 }
}

ResponseDemo2代碼

package com.lingaolu.response;
 
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import java.io.IOException;
 
/**
 * @author 林高祿
 * @create 2020-07-10-15:24
 */
@WebServlet("/responseDemo2")
public class ResponseDemo2 extends HttpServlet {
 @Override
 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  System.out.println("responseDemo2進(jìn)來了......");
 }
 
 @Override
 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  this.doPost(request,response);
 }
}

瀏覽器訪問，訪問前

瀏覽器訪問，訪問后

控制臺輸出

從以上結(jié)果可以看出：

瀏覽器上的請求地址變了
重定向是2次請求，一次是responseDemo1請求，一次是responseDemo2請求

由于狀態(tài)碼固定是302，響應(yīng)頭固定是location，所以請求轉(zhuǎn)發(fā)提供了更方便的方式

void sendRedirect(String var1)

ResponseDemo3代碼

package com.lingaolu.response;
 
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import java.io.IOException;
 
/**
 * @author 林高祿
 * @create 2020-07-10-15:24
 */
@WebServlet("/responseDemo3")
public class ResponseDemo3 extends HttpServlet {
 @Override
 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  System.out.println("responseDemo3進(jìn)來了......");;
  // 動態(tài)獲取虛擬目錄，以后修改虛擬目錄的時(shí)候就不用了修改代碼
  String contextPath = request.getContextPath();
  response.sendRedirect(contextPath+"/responseDemo2");
 
 }
 
 @Override
 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  this.doPost(request,response);
 }
}

啟動，瀏覽器訪問

控制臺輸出

我們把ResponseDemo3代碼改一下，重定向到百度

package com.lingaolu.response;
 
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import java.io.IOException;
 
/**
 * @author 林高祿
 * @create 2020-07-10-15:24
 */
@WebServlet("/responseDemo3")
public class ResponseDemo3 extends HttpServlet {
 @Override
 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  System.out.println("responseDemo3進(jìn)來了......");;
  response.sendRedirect("http://www.baidu.com");
 
 }
 
 @Override
 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  this.doPost(request,response);
 }
}

重啟訪問，就重定向到百度了

從上面結(jié)果我們可以看出，重定向可以訪問其他服務(wù)器的資源

我們寫一個(gè)ResponseDemo4，探索一下共享數(shù)據(jù)情況，ResponseDemo4里請求寫進(jìn)了一個(gè)數(shù)據(jù)name

package com.lingaolu.response;
 
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import java.io.IOException;
 
/**
 * @author 林高祿
 * @create 2020-07-10-15:24
 */
@WebServlet("/responseDemo4")
public class ResponseDemo4 extends HttpServlet {
 @Override
 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  System.out.println("responseDemo4進(jìn)來了......");
  request.setAttribute("name","林大帥");
  String contextPath = request.getContextPath();
  response.sendRedirect(contextPath+"/responseDemo2");
 
 }
 
 @Override
 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  this.doPost(request,response);
 }
}

同時(shí)ResponseDemo2改一下，獲取數(shù)據(jù)name

重啟，瀏覽器訪問