java 原生http服务器测试JS前端ajax访问实现跨域传post数据

后端 java eclipse

字节流转字符

java 复制代码

package Httpv3;


import com.sun.net.httpserver.Headers;
import com.sun.net.httpserver.HttpExchange;
import com.sun.net.httpserver.HttpHandler;
import com.sun.net.httpserver.HttpServer;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetSocketAddress;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.Arrays;

//来源
//https://blog.csdn.net/xietansheng/article/details/78704783

//浏览器访问: http://localhost:8080/、http://localhost:8080/bb，输出: Hello World

//浏览器访问: http://localhost:8080/aa、http://localhost:8080/aa/bb，输出: Hello World AA
//                            版权声明：本文为博主原创文章，遵循 CC 4.0 BY-SA 版权协议，转载请附上原文出处链接和本声明。
//原文链接：https://blog.csdn.net/xietansheng/article/details/78704783

public class Mainv2 {
	public String mydata=new String();
    public static void main(String[] args) throws Exception {
    	
    	String mydatav2= new String();
        // 创建 http 服务器, 绑定本地 8080 端口
        HttpServer httpServer = HttpServer.create(new InetSocketAddress(8080), 0);
        // 创上下文监听, "/" 表示匹配所有 URI 请求
        
        httpServer.createContext("/", new HttpHandler() {
            @Override
            public void handle(HttpExchange httpExchange) throws IOException {
                System.out.println("addr: " + httpExchange.getRemoteAddress() +     // 客户端IP地址
                        "; protocol: " + httpExchange.getProtocol() +               // 请求协议: HTTP/1.1
                        "; method: " + httpExchange.getRequestMethod() +            // 请求方法: GET, POST 等
                        "; URI: " + httpExchange.getRequestURI());                  // 请求 URI

                // 获取请求头
                String userAgent = httpExchange.getRequestHeaders().getFirst("User-Agent");
                System.out.println("User-Agent: " + userAgent);
                
                // 响应内容
//                byte[] respContents = "Hello World".getBytes("UTF-8");
                byte[] respContents = ("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\r\n"
                		+ "<note>\r\n"
                		+ "  <to>Tove</to>\r\n"
                		+ "  <from>Jani</from>\r\n"
                		+ "  <heading>Reminder</heading>\r\n"
                		+ "  <body>Don't forget me this weekend!</body>\r\n"
                		+ "</note>").getBytes("UTF-8");
                // 设置响应头
                
//                httpExchange.getResponseHeaders().add("Content-Type", "text/html; charset=UTF-8");
//               参数解释-允许跨域的各个参数
//              https://developer.mozilla.org/zh-CN/docs/Web/HTTP/Headers/Access-Control-Request-Headers
              httpExchange.getResponseHeaders().add("Access-Control-Allow-Origin","*");
              httpExchange.getResponseHeaders().add("Access-Control-Allow-Headers","*");
              httpExchange.getResponseHeaders().add("Access-Control-Allow-Methods","*");
//              允许接收各种消息头 对应前端 xhr.setRequestHeader('Content-Type', 'application/json');
              httpExchange.getResponseHeaders().add("Access-Control-Request-Headers","*");
              httpExchange.getResponseHeaders().add("Access-Control-Expose-Headers","*" );
//              对应前端特定消息头 xhr.setRequestHeader('Content-Type', 'application/json');
              httpExchange.getResponseHeaders().add("Content-Type", "text/html; charset=UTF-8");
                
              
              // 设置响应code和内容长度
                httpExchange.sendResponseHeaders(200, respContents.length);

                // 设置响应内容
                httpExchange.getResponseBody().write(respContents);
                
//                测试数据
//                String receive = httpExchange.getResponseBody().toString();
//                System.out.println(receive);
//                
//                String receivev2 = httpExchange.getRequestBody().toString();
//                System.out.println(receivev2);
//                获取数组，把其他的body打印出来，发现是asc码
                byte[] receivev3 = httpExchange.getRequestBody().readAllBytes();
                System.out.println(Arrays.toString(receivev3));
                
//                字节流转字符流
                String utf_8 = new String(receivev3,StandardCharsets.UTF_8);
                System.out.println(utf_8);
                
                
                
                
//                String have = Arrays.toString(receivev3);
//                System.out.println(have.toString());
//                System.out.println(have);
//                System.out.println(have.length());
//                for(int i=0;i<have.length();i++) {
//                	System.out.println((char)receivev3[i]);
//                }
                
//                char[] message = new char[1000];
//                 String str = new String();
//                 String s=new String();
//                for(int i=0;i<have.length()-2;i++) {
//                	message[i]=(char)receivev3[i];
//                	System.out.println(message[i]);
//                	字符变字符串
//                	s=Character.toString(message[i]);
//                	System.out.println(s);
//                	字符串追加到 str
//                	str=str.concat(s);
//                	System.out.println(str);
//                	System.out.println(str.length());
                	
//                }
                
                
                
                
//                mydatav2.copyValueOf(message);
//                
//                System.out.println("revieve"+str);
//                System.out.println(str);
//                System.out.println(have.length());
//                
//                System.out.println("mydatav2"+mydatav2);
                
                
                
                
//                System.out.println(str.length());
//                System.out.println(Arrays.toString(receivev3));
                
                
//                InputStream have = httpExchange.getRequestBody();
//                byte[] posting = have.readAllBytes();
//                System.out.println(Arrays.toString(posting));
                
                // 关闭处理器
                httpExchange.close();
                
//              来源
//              https://vimsky.com/examples/detail/java-method-com.sun.net.httpserver.HttpExchange.getResponseHeaders.html

                
//                Headers responseHeaders = httpExchange.getResponseHeaders();
//        	    responseHeaders.add("Access-Control-Allow-Origin", "*");
//        	    responseHeaders.add("Access-Control-Allow-Headers", "*");
//        	    X-Custom-Header
//              httpExchange.getResponseHeaders().add("Content-Type", "text/html; charset=UTF-8");
//        	    httpExchange.getResponseHeaders().add("Access-Control-Allow-Methods","*");
//        	    httpExchange.sendResponseHeaders(200, respContents.length);
//        	    OutputStream outputStream = httpExchange.getResponseBody();
//        	    outputStream.write(httpExchange.getResponseCode());
//        	    outputStream.close();
                
//        	    byte[] respContentsv3 = "Hello World".getBytes("UTF-8");
//        	    httpExchange.sendResponseHeaders(200, respContentsv3.length);
//        	    httpExchange.getResponseBody().write(respContentsv3);
        	    
//        	    System.out.println("message"+httpExchange.getRequestBody().toString());
        	    
//        	    httpExchange.close();
                
            }
            
            
            
        });

        // 创建上下文监听, 处理 URI 以 "/aa" 开头的请求
        httpServer.createContext("/aa", new HttpHandler() {
            @Override
            public void handle(HttpExchange httpExchange) throws IOException {
                byte[] respContents = "Hello World AA".getBytes("UTF-8");
                
                httpExchange.getResponseHeaders().add("Content-Type", "text/html; charset=UTF-8");
                httpExchange.sendResponseHeaders(200, respContents.length);

                httpExchange.getResponseBody().write(respContents);
                httpExchange.close();
//                来源
//                https://vimsky.com/examples/detail/java-method-com.sun.net.httpserver.HttpExchange.getResponseHeaders.html
                // Add the header to avoid error:
        	    // "No 'Access-Control-Allow-Origin' header is present on the requested resource"
//                
//                Headers responseHeaders = httpExchange.getResponseHeaders();
//        	    responseHeaders.add("Access-Control-Allow-Origin", "*");
//        	    httpExchange.sendResponseHeaders(200, respContents.length);
//
//        	    OutputStream outputStream = httpExchange.getResponseBody();
//        	    outputStream.write(httpExchange.getResponseCode());
//        	    outputStream.close();
//        	    
        	    
        	    
            }
            
        });

        // 启动服务
        httpServer.start();
    }

}

前端

html 复制代码

<!DOCTYPE html>

<!-- 来源 -->
<!-- https://cloud.tencent.com/developer/article/1705089 -->
<!-- https://geek-docs.com/ajax/ajax-questions/19_ajax_javascript_send_json_object_with_ajax.html -->
<!-- 配合java后端可以监听 -->
<!-- //原文链接：https://blog.csdn.net/xietansheng/article/details/78704783 -->


<html lang="en">
	<head>
		<meta charset="UTF-8">
		<title>Title</title>
		<script>
			function fun() {
				//发送异步请求
				//1、创建核心对象
				// var xmlhttp;
				// if (window.XMLHttpRequest) { //code for IE7+,Firefox,chrome,opera,safari
				// 	xmlhttp = new XMLHttpRequest();
				// } else { //code for IE6,IE5
				// 	xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
				// }
				// //2、建立连接
				// /*
				//  * 参数：请求方式、请求的url路径、同步或异步请求（true为异步）
				//  * get方式：请求参数在url后面拼接，send方法为空；
				//  * post方式：请求参数在send方法中定义。
				//  * */
				// xmlhttp.open("GET", "ajaxServlet?username=Tim", true);
				
				// //3、发送请求
				// xmlhttp.send();
				// //4、接收及处理响应结果,当服务器响应成功了再获取
				// xmlhttp.onreadystatechange = function() { //当xmlhttp对象就绪状态改变时会触发事件
				// 	if (xmlhttp.readyState == 4 && xmlhttp.status == 200) { //请求已完成且响应就绪,响应状态码为200
				// 		alert(xmlhttp.responseText);
				// 	}
				// };
				
				// https://geek-docs.com/ajax/ajax-questions/19_ajax_javascript_send_json_object_with_ajax.html
				
				
				// 创建XMLHttpRequest对象
				var xhr = new XMLHttpRequest();
				
				// 设置请求类型和URL
				// xhr.open('POST', 'http://example.com/api', true);
				// xhr.open('POST', 'http://localhost:8080/aa', true);
				// xhr.open('POST', '/aa', true);
				// xhr.open('POST', 'http://localhost:8080/aa', true);
				xhr.open('POST', 'http://localhost:8080', true);
				// 设置请求头
				xhr.setRequestHeader('Content-Type', 'application/json');
				
				// xhr.setRequestHeader('X-Custom-Header', 'value');
				// xhr.setRequestHeader('Access-Control-Allow-Origin','*');
				console.log("请求头已设置\n");
				// 监听服务器响应
				// xhr.onreadystatechange = function() {
				//   if (xhr.readyState === 4 && xhr.status === 200) {
				//     // 从服务器获取响应
				//     var response = JSON.parse(xhr.responseText);
				//     console.log(response);
				// 	console.log(getAllResponseHeaders());
				//   }
				// };
				
				// 构建JSON对象
				var data = {
				  name: 'John',
				  age: 25,
				  email: '[email protected]'
				};
				
				// 将JSON对象转换为字符串
				var jsonData = JSON.stringify(data);
				
				// 发送数据
				xhr.send(jsonData);
				// 注释掉就会爆 POST 错误提示

				//4、接收及处理响应结果,当服务器响应成功了再获取
				xhr.onreadystatechange = function() { //当xmlhttp对象就绪状态改变时会触发事件
					if (xhr.readyState == 4 && xhr.status == 200) { //请求已完成且响应就绪,响应状态码为200
						alert(xhr.responseText);
						console.log("检测的正确的返回\n");
					}else{
						console.log("检测到错误的返回\n");
					}
					console.log("检测到返回函数\n");
				};
				
			}
		</script>
	</head>
	<body>
		<input type="button" value="发送异步请求" onclick="fun();">
		<input type="text">
	</body>
</html>

java 原生http服务器 测试JS前端ajax访问实现跨域传post数据

java 原生http服务器测试JS前端ajax访问实现跨域传post数据