使用Ajax优化密码登录

导入阿里巴巴的fastjson

<!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.78</version>
</dependency>

设置session过期时间

<!--默认session过期时间-->
    <session-config>
        <session-timeout>30</session-timeout>
    </session-config>

后台代码修改

 //验证旧密码,session中有用户的密码
    public void pwdmodify(HttpServletRequest req, HttpServletResponse resp){
        //从session里面拿ID;
        Object o = req.getSession().getAttribute(Constants.USER_SESSION);
        String oldpassword = req.getParameter("oldpassword");
        //万能的map
        HashMap<String,String> resultMap = new HashMap<String,String>();
        if (o==null){//session失效了,session过期了
            resultMap.put("result","sessionerror");
        }else if(StringUtils.isNullOrEmpty(oldpassword)){//输入密码为空
            resultMap.put("result","error");
        }else {
            String userPassword = ((User) o).getUserPassword();//session中用户的密码
            if (oldpassword.equals(userPassword)){
                resultMap.put("result","true");
            }else{
                resultMap.put("result","false");
            }
        }
        resp.setContentType("application/json");
        try {
            PrintWriter writer = resp.getWriter();
            //JSONAray阿里巴巴的工具类,转换格式
            /*
            resultMap = ["result","sessionerror","result","error"]
            Json格式 = {key:value}
             */
            writer.write(JSONArray.toJSONString(resultMap));
            writer.flush();
            writer.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}