AJAX跨域使用代理Servlet避开浏览器的CORS机制绕过浏览器实现跨域------AJAX

た入场券 2024-02-18 12:24 11阅读 0赞

>     <!DOCTYPE html>
>     <html lang="en">
>     <head>
>         <meta charset="UTF-8">
>         <title>Title</title>
>     </head>
>     <body>
>         <script type="text/javascript" src="JS/jQuery-1.0.0.js"></script>
>         <script type="text/javascript">
>             $(function()
>             {
>                $("#btn").click(function(){
>                    var ajax = new XMLHttpRequest();
>                    ajax.onreadystatechange = function()
>                    {
>                        if (ajax.readyState === 4)
>                        {
>                            if (ajax.status === 200)
>                            {
>                                $("#myDiv").html(ajax.responseText);
>                            }
>                            else
>                            {
>                                alert(ajax.status);
>                            }
>                        }
>                    }
>                    ajax.open("GET","http://localhost:8080/ajax/Proxy",true);
>                    ajax.send();
>                });
>             });
>         </script>
>         <button id="btn">使用代理机制实现的ajax跨域请求</button>
>         <div id="myDiv"></div>
>     </body>
>     </html>
> 
>     <!DOCTYPE html>
>     <html lang="en">
>     <head>
>         <meta charset="UTF-8">
>         <title>Title</title>
>     </head>
>     <body>
>         <script type="text/javascript" src="JS/jQuery-1.0.0.js"></script>
>         <script type="text/javascript">
>             $(function()
>             {
>                $("#btn").click(function(){
>                    var ajax = new XMLHttpRequest();
>                    ajax.onreadystatechange = function()
>                    {
>                        if (ajax.readyState === 4)
>                        {
>                            if (ajax.status === 200)
>                            {
>                                $("#myDiv").html(ajax.responseText);
>                            }
>                            else
>                            {
>                                alert(ajax.status);
>                            }
>                        }
>                    }
>                    ajax.open("GET","http://localhost:8080/ajax/Proxy",true);
>                    ajax.send();
>                });
>             });
>         </script>
>         <button id="btn">使用代理机制实现的ajax跨域请求</button>
>         <div id="myDiv"></div>
>     </body>
>     </html>

>     package com.bjpowernode.AJAX;
>     
>     import jakarta.servlet.ServletException;
>     import jakarta.servlet.annotation.WebServlet;
>     import jakarta.servlet.http.HttpServlet;
>     import jakarta.servlet.http.HttpServletRequest;
>     import jakarta.servlet.http.HttpServletResponse;
>     import org.apache.http.HttpEntity;
>     import org.apache.http.HttpResponse;
>     import org.apache.http.client.methods.HttpGet;
>     import org.apache.http.impl.client.CloseableHttpClient;
>     import org.apache.http.impl.client.HttpClients;
>     
>     import java.io.BufferedReader;
>     import java.io.IOException;
>     import java.io.InputStreamReader;
>     
>     @WebServlet("/Proxy")
>     public class ProxyServlet extends HttpServlet
>     {
>         @Override
>         protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             //通过HttpClient发送get或者post请求,访问我们另一个服务器
>             String url = "http://localhost:8081/Test/hello";
>             HttpGet httpGet = new HttpGet(url);
>             // 设置类型 "application/x-www-form-urlencoded" "application/json"
>             httpGet.setHeader("Content-Type", "application/x-www-form-urlencoded");
>             System.out.println("调用URL: " + httpGet.getURI());//        httpClient实例化
>             CloseableHttpClient httpClient = HttpClients.createDefault();
>             // 执行请求并获取返回
>             HttpResponse resp = httpClient.execute(httpGet);//
>             System.out.println("Response toString()" + resp.toString());
>             HttpEntity entity = resp.getEntity();
>             System.out.println("返回状态码：" + resp.getStatusLine());
>             //得到返回数据的长度；没有该参数返回-1//
>             if (entity != null)
>             {
>                 System.out.println("返回消息内容长度: " + entity.getContentLength());
>             }
>             // 显示结果
>             BufferedReader reader = new BufferedReader(new InputStreamReader(entity.getContent(), "UTF-8"));
>             String line = null;
>             StringBuffer responseSB = new StringBuffer();
>             while ((line = reader.readLine()) != null) {
>                 responseSB.append(line);
>             }
>             System.out.println("返回消息：" + responseSB);
>             response.getWriter().println(responseSB);
>             reader.close();
>             httpClient.close();
>         }
>     }
> 
>     package com.bjpowernode.AJAX;
>     
>     import jakarta.servlet.ServletException;
>     import jakarta.servlet.annotation.WebServlet;
>     import jakarta.servlet.http.HttpServlet;
>     import jakarta.servlet.http.HttpServletRequest;
>     import jakarta.servlet.http.HttpServletResponse;
>     import org.apache.http.HttpEntity;
>     import org.apache.http.HttpResponse;
>     import org.apache.http.client.methods.HttpGet;
>     import org.apache.http.impl.client.CloseableHttpClient;
>     import org.apache.http.impl.client.HttpClients;
>     
>     import java.io.BufferedReader;
>     import java.io.IOException;
>     import java.io.InputStreamReader;
>     
>     @WebServlet("/Proxy")
>     public class ProxyServlet extends HttpServlet
>     {
>         @Override
>         protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             //通过HttpClient发送get或者post请求,访问我们另一个服务器
>             String url = "http://localhost:8081/Test/hello";
>             HttpGet httpGet = new HttpGet(url);
>             // 设置类型 "application/x-www-form-urlencoded" "application/json"
>             httpGet.setHeader("Content-Type", "application/x-www-form-urlencoded");
>             System.out.println("调用URL: " + httpGet.getURI());//        httpClient实例化
>             CloseableHttpClient httpClient = HttpClients.createDefault();
>             // 执行请求并获取返回
>             HttpResponse resp = httpClient.execute(httpGet);//
>             System.out.println("Response toString()" + resp.toString());
>             HttpEntity entity = resp.getEntity();
>             System.out.println("返回状态码：" + resp.getStatusLine());
>             //得到返回数据的长度；没有该参数返回-1//
>             if (entity != null)
>             {
>                 System.out.println("返回消息内容长度: " + entity.getContentLength());
>             }
>             // 显示结果
>             BufferedReader reader = new BufferedReader(new InputStreamReader(entity.getContent(), "UTF-8"));
>             String line = null;
>             StringBuffer responseSB = new StringBuffer();
>             while ((line = reader.readLine()) != null) {
>                 responseSB.append(line);
>             }
>             System.out.println("返回消息：" + responseSB);
>             response.getWriter().println(responseSB);
>             reader.close();
>             httpClient.close();
>         }
>     }

>     import jakarta.servlet.ServletException;
>     import jakarta.servlet.annotation.WebServlet;
>     import jakarta.servlet.http.HttpServlet;
>     import jakarta.servlet.http.HttpServletRequest;
>     import jakarta.servlet.http.HttpServletResponse;
>     
>     import java.io.IOException;
>     
>     @WebServlet("/hello")
>     public class Hello extends HttpServlet
>     {
>         @Override
>         protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
>             request.setCharacterEncoding("UTF-8");
>             response.setCharacterEncoding("UTF-8");
>             response.setContentType("text/html;charset=UTF-8");
>             //设置响应头
>     //        response.setHeader("Access-Control-Allow-Origin","http://localhost:8080");
>             //跨域访问的资源允许访问,设置响应头的方式原理是
>     
>             response.getWriter().println("{\"username\" : \"zhangSan\"};");
>         }
>     }
> 
>     import jakarta.servlet.ServletException;
>     import jakarta.servlet.annotation.WebServlet;
>     import jakarta.servlet.http.HttpServlet;
>     import jakarta.servlet.http.HttpServletRequest;
>     import jakarta.servlet.http.HttpServletResponse;
>     
>     import java.io.IOException;
>     
>     @WebServlet("/hello")
>     public class Hello extends HttpServlet
>     {
>         @Override
>         protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
>             request.setCharacterEncoding("UTF-8");
>             response.setCharacterEncoding("UTF-8");
>             response.setContentType("text/html;charset=UTF-8");
>             //设置响应头
>     //        response.setHeader("Access-Control-Allow-Origin","http://localhost:8080");
>             //跨域访问的资源允许访问,设置响应头的方式原理是
>     
>             response.getWriter().println("{\"username\" : \"zhangSan\"};");
>         }
>     }