微信小程序实现前后端简单通信(Java服务器)

wxml:写一个<button>组件.代码如下:

<button bindtap='sent'>发送请求</button>

js:向服务器发起请求.代码如下:

sent: function () {
    wx.login({
        success(res) {
            if (res.code) {
                //发起网络请求
                wx.request({
                   url:'http://YourIP/项目名/servlet/servlet',
                   data: {
                        code: res.code
                    },
                    success: function (res) {
                        console.log(res.data)
                    }
                })
            } else {
                console.log('登录失败！' + res.errMsg)
            }
        }
    })
}

服务端:新建一个servlet.内容如下:

package servlet;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.swing.text.html.HTML;
import java.io.IOException;
import java.io.PrintWriter;

/**
 * @Author 盛文增
 * @Date 2019/7/6 19:56
 * @Version 1.0
 */
@WebServlet(name = "Servlet")
public class Servlet extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("成功!");
        String code = request.getParameter("code");
        PrintWriter out = response.getWriter();
        out.write(code);
        out.flush();
        out.close();
    }
}

在xml中注册:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
		  http://java.sun.com/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">
    <servlet>
        <servlet-name>Servlet</servlet-name>
        <servlet-class>servlet.Servlet</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>Servlet</servlet-name>
        <url-pattern>/servlet/servlet</url-pattern>
    </servlet-mapping>
</web-app>

此时按下小程序的按钮,触发js事件,向服务器发送带code的get请求,服务器收到请求后,将code返回小程序,小程序再将返回的code输出到控制台.这样就完成了从小程序前端向服务器通讯的过程.

内网穿透工具:花生壳

private static final String APP_ID = "wxed13841872660831";
private static final String APP_SECRET = "7cee96eb3933389359ba81d9fa253752";
private static String url = "https://api.weixin.qq.com/sns/jscode2session?appid=APPID&secret=SECRET&js_code=JSCODE&grant_type=authorization_code";