首先需要导入三个必需的jar包：
1.mail.jar
2.activation-1.1.1.jar
3.javax.mail-1.6.0.jar

第二。将三个jar包构建路径： 点击 Add to Aspectpath,三个jar包都需要。
Controller代码：`

import org.springframework.mail.SimpleMailMessage;
import org.springframework.mail.javamail.JavaMailSender;//这两个确保导入成功，未报异常

@Controller
public class SendEmailController {
	@Autowired
    private JavaMailSender javaMailSender;
    @RequestMapping("send")
    public @ResponseBody  void  senMsg(HttpSession httpSession, @RequestParam String email){
        //生成六位数验证码
        String Captcha = String.valueOf(new Random().nextInt(899999) + 100000);
        httpSession.setAttribute("Captcha",Captcha);
        SimpleMailMessage message = new SimpleMailMessage();
        //发件人的邮箱地址
        message.setFrom("XXXXXX@qq.com");
        //收件人的邮箱地址
        message.setTo(email);
        //邮件主题
        message.setSubject("邮件的主题");
        //邮件内容
        message.setText("欢迎您注册地软平台："+Captcha+"若想要了解相关消息，请访问官网：xxxxxxxxx");
        //发送邮件
        javaMailSender.send(message);        
    }

注册-Controller：

@RequestMapping("Register-QAZXFSDFGER")
	@ResponseBody
	public String Register(String username,String nickname,String password,String phone,String email,String emailcode,
			HttpSession session,HttpServletRequest req) {		 
		String sessionemailcode =(String) session.getAttribute("Captcha");
		if(emailcode.equals(sessionemailcode)&&emailcode!=null&&sessionemailcode!=null)
		{
			int userid = (int)(Math.random()*100000);
`userservice.Register(userid,username,nickname,password,phone,email);
//注册成功返回登录
			return "OK";
		}
		//注册失败返回注册页
		return "No"; 
	}``

注册jsp页面-ajax：

<script>
  function Register(){
        var username = $("#username").val();
        var nickname = $("#nickname").val();
        var password = $("#password").val();
        var phone = $("#phone").val();
        var emailer = $("#emailer").val();   
        var emailcode=$("#emailboxcode").val();      
        $.ajax({
            url:"Register-QAZXFSDFGER", //要处理的页面
            data:{username:username,nickname:nickname,password:password,phone:phone,email:emailer,emailcode:emailcode},  //要传过去的数据
            type:"POST",           
            dataType:"TEXT", //返回的数据类型，TEXT字符串 JSON返回JSON XML返回XML；dataType中T要大写！！
            success: function(data){
            	if(data=="OK")
            	{
            		window.location.href ='Login-Success';
            	}else{
            		
            	}
           },
           error:function(){
        	   alert("注册失败");
           }
            
        });
  }
    </script>`
    //注册表单代码：
<div class="middle-box text-center loginscreen   animated fadeInDown">
        <div>
            <div>        </div>
            <h3>欢迎注册 地质大数据平台</h3>
            <p>创建一个PFAS新账户</p> 
                <div class="form-group">
                    <input type="text" class="form-control" id="username" placeholder="请输入真实姓名" required="">
                </div>
                <div class="form-group">
                    <input type="text" class="form-control" id="nickname" placeholder="请输入昵称" required="">
                </div>
                <div class="form-group">
                    <input type="password" class="form-control" id="password" placeholder="请输入用户密码" required="">
                </div>
                <div class="form-group">
                    <input type="password" class="form-control"  placeholder="请再次输入用户密码" required="">
                </div>
                <div class="form-group">
                    <input type="text" class="form-control" id="phone" placeholder="请输入手机号" required="">
                </div>                
                <form action="send" method="post">
                    <button type="submit" style=" width:100px;height:30px;" >发送验证码</button>                 
                    <input type="text" class="form-control" placeholder="请输入邮箱" style=" margin-bottom:10px;margin-top:10px;"  name="email" id="emailer" >
                    <input type="text" class="form-control" placeholder="请输入邮箱验证码" style=" margin-bottom:50px;" name="emailboxcode" id="emailboxcode" >
          		</form>               
                
                <button  class="btn btn-primary block full-width m-b" onclick="Register()">注 册</button>
                <p class="text-muted text-center"><small>注册代表同意该协议-</small><a href="login.html">网站协议</a>
                </p>       
        </div>
    </div>
`