预备知识(备查):
1)element-ui使用手册
2)vue+servlet
3 ) axios
建表语句
CREATE TABLE `t_user` (
`user_id` int(11) NOT NULL AUTO_INCREMENT,
`user_name` varchar(255) DEFAULT NULL,
`user_pwd` varchar(255) DEFAULT NULL,
`user_email` varchar(255) DEFAULT NULL,
`user_idcard` varchar(255) DEFAULT NULL,
`user_power` int(255) DEFAULT NULL,
PRIMARY KEY (`user_id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8;
SET FOREIGN_KEY_CHECKS=1;
目标
本章制作前后端分离的项目,前后端实现跨域访问
- 注册功能开发
项目位置
前台vue:d:\vue\web-vue
后台servlet:D:\study\my12306_vue
框架选择
前端框架选择element-ui
跨域请求选择axios
第一步:新建工程web-vue,并导入常用的包
1.1 d:\vue进入命令行状态,输入以下命令
vue init webpack web-vue
注意:中间有一项eslint选n
1.2 进入d:\vue\web-vue目录,输入以入命令
cnpm install
cnpm install vue-router vue-resource --save
cnpm install element-ui -S
cnpm install axios --save
cnpm install --save vue-axios
cnpm install qs
cnpm install vuex --save
1.3 确认是否安装成功(axios同理)
查看配置文件package.json,是否有element-ui组件的版本号 如下图:
在node_modules中可以看到 element-ui的文件夹 ,所有安装的源文件可以在这里面找到
第二步 编码
参考官网:https://element.eleme.cn/#/zh-CN/component/quickstart
在main.js文件中引入 element 组件
以下步骤皆可查看element手册
step 1 引入
引入方式有两种 1)完整引入 2)按需引入 初学者可以选择完整引入,以后熟练了再按需引入
完整引入
在 main.js 中写入以下内容:
import Vue from 'vue';
import ElementUI from 'element-ui';
import 'element-ui/lib/theme-chalk/index.css';
import App from './App.vue';
Vue.use(ElementUI);
new Vue({
el: '#app',
render: h => h(App)
});
注意,如有与原有引入重复的,要出重复。比如vue,app就不需要重复引入
国际化(了解)
Element 组件内部默认使用中文,若希望使用其他语言,则需要进行多语言设置。以英文为例,在 main.js 中:
import lang from 'element-ui/lib/locale/lang/en'
import locale from 'element-ui/lib/locale'
// 设置语言
locale.use(lang)
经过上述两步,完成了element-ui的引入
引入qs备用
import qs from 'qs';
Vue.prototype.$qs = qs;
axios vuex 引入略,直接上main.js完整代码
1)main.js完整的代码如下
// The Vue build version to load with the `import` command
// (runtime-only or standalone) has been set in webpack.base.conf with an alias.
import Vue from 'vue'
import App from './App'
import router from './router'
import ElementUI from 'element-ui'
import 'element-ui/lib/theme-chalk/index.css'
import lang from 'element-ui/lib/locale/lang/en'
import locale from 'element-ui/lib/locale'
//以下4行引入axios
import axios from 'axios'
import VueAxios from 'vue-axios'
axios.defaults.withCredentials = true//这个默认即为false,如果改为true,可以传递session信息,后端要做相应修改来放行,
Vue.prototype.$axios = axios //在vue中使用axios
//vuex组件,用于state管理
import Vuex from 'vuex';
// 设置语言
locale.use(lang)
Vue.use(ElementUI);
Vue.use(Vuex);
import qs from 'qs';
Vue.prototype.$qs = qs;
/* eslint-disable no-new */
new Vue({
el: '#app',
router,
components: { App },
template: '<App/>'
})
测试
进入命令行状态运行
npm run dev
浏览器输入http://localhost:8080/#/,出现如下页面即为成功
image.png2)编写注册页面Register.vue
https://element.eleme.cn/#/zh-CN/component/form
页面里找到如下表单,
在src/components目录下新建user目录
后在目录下新建Register.vue文件
拷贝element-ui对应页面的内容到Register.vue里
如图:
image.png
3)路由文件router/index.js
import Vue from 'vue'
import Router from 'vue-router'
import HelloWorld from '@/components/HelloWorld'
import Register from '@/components/reg/Register.vue'
Vue.use(Router)
export default new Router({
routes: [
{
path: '/',
name: 'HelloWorld',
component: HelloWorld
},{
path: '/reg',
name: 'Register',
component: Register
}
]
})
启动并测试:
npm run dev
http://localhost:8080/#/reg
image.png
继续完成界面开发
<template>
<el-form :model="ruleForm" :rules="rules" ref="ruleForm" label-width="100px" class="demo-ruleForm">
<el-form-item label="用户名" prop="username">
<el-input v-model="ruleForm.username"></el-input>
</el-form-item>
<el-form-item label="密码" prop="pass">
<el-input type="password" v-model="ruleForm.pass" autocomplete="off"></el-input>
</el-form-item>
<el-form-item label="确认密码" prop="checkPass">
<el-input type="password" v-model="ruleForm.checkPass" autocomplete="off"></el-input>
</el-form-item>
<el-form-item label="邮箱" prop="email">
<el-input v-model="ruleForm.email"></el-input>
</el-form-item>
<el-form-item label="身份证号" prop="idcard">
<el-input v-model="ruleForm.idcard"></el-input>
</el-form-item>
<el-form-item>
<el-button type="primary" @click="submitForm('ruleForm')">立即创建</el-button>
<el-button @click="resetForm('ruleForm')">重置</el-button>
</el-form-item>
</el-form>
</template>
<script>
export default {
data() {
var validatePass = (rule, value, callback) => {
if (value === '') {
callback(new Error('请输入密码'));
} else {
if (this.ruleForm.checkPass !== '') {
this.$refs.ruleForm.validateField('checkPass');
}
callback();
}
};
var validatePass2 = (rule, value, callback) => {
if (value === '') {
callback(new Error('请再次输入密码'));
} else if (value !== this.ruleForm.pass) {
callback(new Error('两次输入密码不一致!'));
} else {
callback();
}
};
return {
ruleForm: {
username: '',
pass: '',
checkPass: '',
email: '',
idcard: ''
},
rules: {
username: [{
required: true,
message: '请输入活动名称',
trigger: 'blur'
},
{
min: 6,
max: 20,
message: '长度在 6 到 20 个字符',
trigger: 'blur'
}
],
pass: [{
required: true,
validator: validatePass,
trigger: 'blur'
}],
checkPass: [{
required: true,
validator: validatePass2,
trigger: 'blur'
}]
}
};
},
methods: {
submitForm(formName) {
this.$refs[formName].validate((valid) => {
if (valid) {
alert('submit!');
} else {
console.log('error submit!!');
return false;
}
});
},
resetForm(formName) {
this.$refs[formName].resetFields();
}
}
}
</script>
<style>
</style>
第四步:后台D:\study\my12306_vue
引入必要的包:
image.png1)src的com.neuedu.utils包下新建一个过滤器,增加跨域权限配置CorsFilter.java内容如下
package com.neuedu.utils;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet Filter implementation class CorsFilter
*/
@WebFilter(filterName="/CodeFilter",urlPatterns="/*")
public class CorsFilter implements Filter {
private final int time = 20 * 24 * 60 * 60;
/**
* Default constructor.
*/
public CorsFilter() {
// TODO Auto-generated constructor stub
}
/**
* @see Filter#destroy()
*/
public void destroy() {
// TODO Auto-generated method stub
}
/**
* @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)
*/
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
HttpServletResponse resp = (HttpServletResponse) response;
// 允许跨域的主机地址,允许任意domain访问
//坑:前台axios设置withCredentials: true后,Access-Control-Allow-Origin的值不可以为*
resp.setHeader("Access-Control-Allow-Origin", "http://localhost:8080");
/* 允许跨域的请求头 */
resp.setHeader("Access-Control-Allow-Headers", "*");
/* 允许跨域的请求方法GET, POST, HEAD 等 */
resp.setHeader("Access-Control-Allow-Methods", "PUT,POST,GET,DELETE,OPTIONS");
/* 重新预检验跨域的缓存时间 (s) */
resp.setHeader("Access-Control-Max-Age", time + "");
/* 是否携带cookie,session支持 */
resp.setHeader("Access-Control-Allow-Credentials", "true");
chain.doFilter(request, resp);
}
......
}
db.properties 下增加如下设置
driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/java16?characterEncoding=UTF-8&useUnicode=true
userName=root
passWord=root
数据库工具类DBUtil.java主要代码
// 用于数据库连接的方法
public static Connection getConnection() {
Connection conn = null;
try {
//载入资源文件
Properties prop=new Properties();
prop.load(DBUtil.class.getResourceAsStream("/db.properties"));
//读取资源文件各属性
String driver=prop.getProperty("driver");
String url = prop.getProperty("url");
String UserName = prop.getProperty("userName");
String password = prop.getProperty("passWord");
Class.forName(driver);
conn = DriverManager.getConnection(url, UserName, password);
} catch (Exception e) {
e.printStackTrace();
System.out.println("数据库连接异常" + e.getMessage());
}
return conn;
}
User 实体类
package com.neuedu.pojo;
public class User {
// 主键id,自增
private int id;
private String userName;
private String userPwd;
private String email;
private String idCard;
private String userPwd1;
private int power=0;
.......省略get/set
}
2)RegServlet
@WebServlet("/regServlet")
public class RegServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request,response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//request.setCharacterEncoding("utf-8");
//response.setCharacterEncoding("utf-8");
//接收用户输入
String name=request.getParameter("username");
System.out.println(name);
String password=request.getParameter("passwrod");
String repassword=request.getParameter("checkPass");
String email=request.getParameter("email");
String idCard=request.getParameter("idcard");
//String[] cookieFlag=request.getParameterValues("CookieYN");
//System.out.println(cookieFlag);
//打包user
User user=new User();
user.setUserName(name);
user.setUserPwd(password);
user.setUserPwd1(repassword);
user.setEmail(email);
user.setIdCard(idCard);
//调用service进行处理
IUserService userService=new UserServiceImpl();
int i=userService.addUser(user);
//返回处理结果
response.setContentType("text/html;charset=utf-8");
PrintWriter out=response.getWriter();
if(i>0){
out.println("success");
}else{
out.println("failure");
}
}
}
UserServiceImpl
public class UserServiceImpl implements IUserService {
IUserDao userDao=new UserDaoImpl();
@Override
public int addUser(User user) {
int i=0;
//验证合法性
//比如用户名是否重复
//两次密码是否一致。。。。。。
//如果验证通过,就存库
User dbuser=userDao.getUser(user);
//调用dao存库
if(dbuser!=null){//已经被注册过了
return 0;
}else{
i=userDao.add(user);
}
return i;
}
@Override
public User getUser(User user) {
return userDao.getUser(user);
}
}
UserDaoImpl
public class UserDaoImpl implements IUserDao {
PreparedStatement ps=null;
Connection conn=null;
ResultSet rs=null;
@Override
public int add(User user) {
int i=0;
try {
conn=DBUtil.getConnection();
ps=conn.prepareStatement("INSERT INTO t_user VALUES(NULL,?,?,?,?,?)");
ps.setString(1,user.getUserName());
ps.setString(2,user.getUserPwd());
ps.setString(3,user.getEmail());
ps.setString(4,user.getIdCard());
ps.setInt(5, user.getPower());
i=ps.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
}
return i;
}
@Override
public User getUser(User user) {
User dbuser=null;
conn=DBUtil.getConnection();
try {
ps=conn.prepareStatement("select * from t_user where user_name=? and user_pwd=?");
ps.setString(1, user.getUserName());
ps.setString(2, user.getUserPwd());
rs=ps.executeQuery();
if(rs.next()){//如果有该用户
dbuser=new User();
dbuser.setId(rs.getInt("user_id"));
dbuser.setUserName(rs.getString("user_name"));
dbuser.setUserPwd(rs.getString("user_pwd"));
dbuser.setEmail(rs.getString("user_email"));
dbuser.setIdCard(rs.getString("user_idcard"));
dbuser.setPower(rs.getInt("user_power"));
}
} catch (SQLException e) {
e.printStackTrace();
}
DBUtil.closeConnection(rs, ps, conn);
return dbuser;
}
}
页面添加axios请求
改造methods部分
methods: {
submitForm(formName) {
this.$refs[formName].validate((valid) => {
if (valid) {
//alert('submit!');
//此处为新增加代码,用于请求后台进行注册
let obj = this.$qs.stringify(this.ruleForm)
//此处为新增加代码,用于请求后台进行注册
this.$axios.post('http://localhost:8082/my12306_vue/regServlet', obj)
.then(response => {
alert(response.data);
})
} else {
console.log('error submit!!');
return false;
}
});
},
resetForm(formName) {
this.$refs[formName].resetFields();
}
}
测试
npm run dev
启动服务,浏览器输入
http://localhost:8080/#/reg
点击save按钮,显示成功
image.png
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