好久没更博了…
最近看了个真正全注解实现的 SpringMVC 博客,感觉很不错,终于可以彻底丢弃 web.xml 了。其实这玩意也是老东西了,丢弃 web.xml,是基于 5、6年前发布的 Servlet 3.0 规范,只不过少有人玩而已…现在4.0都快正式发布了…Spring对注解的支持也从09年底就开始支持了…
基础部分我就不仔细讲了,可以先看一下这篇 以及其中提到的另外两篇文章,这三篇文章讲的很不错。
下面开始旧东西新玩~~~

构建

项目是基于 gradle 3.1构建的,这是项目依赖:

dependencies {
  def springVersion = '4.3.2.RELEASE'

  compile "org.springframework:spring-web:$springVersion"
  compile "org.springframework:spring-webmvc:$springVersion"
  compile "redis.clients:jedis:2.9.0"
  compile "javax.servlet:javax.servlet-api:3.1.0"
  compile "org.json:json:20160810"
}

编写Java版的web.xml

想要让请求经过Java,少不了配置 web.xml,不过现在我们来写个Java版的~
这里和传统的 web.xml 一样,依次添加 filterservlet

package org.xueliang.loginsecuritybyredis.commons;

import javax.servlet.FilterRegistration;
import javax.servlet.Servlet;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRegistration;

import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.filter.CharacterEncodingFilter;
import org.springframework.web.servlet.DispatcherServlet;

/**
 * 基于注解的/WEB-INF/web.xml
 * 依赖 servlet 3.0
 * @author XueLiang
 * @date 2016年10月24日 下午5:58:45
 * @version 1.0
 */
public class CommonInitializer implements WebApplicationInitializer {

    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {

        // 基于注解配置的Web容器上下文
        AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
        context.register(WebAppConfig.class);

        // 添加编码过滤器并进行映射
        CharacterEncodingFilter characterEncodingFilter = new CharacterEncodingFilter("UTF-8", true);
        FilterRegistration.Dynamic dynamicFilter = servletContext.addFilter("characterEncodingFilter", characterEncodingFilter);
        dynamicFilter.addMappingForUrlPatterns(null, true, "/*");

        // 添加静态资源映射
        ServletRegistration defaultServletRegistration = servletContext.getServletRegistration("default");
        defaultServletRegistration.addMapping("*.html");

        Servlet dispatcherServlet = new DispatcherServlet(context);
        ServletRegistration.Dynamic dynamicServlet = servletContext.addServlet("dispatcher", dispatcherServlet);
        dynamicServlet.addMapping("/");
    }
}

这一步走完,Spring 基本上启动起来了。

编写Java版的Spring配置

现在Spring已经可以正常启动了,但我们还要给 Spring 做一些配置,以便让它按我们需要的方式工作~
这里因为后端只负责提供数据,而不负责页面渲染,所以只需要配置返回 json 视图即可,个人比较偏爱采用内容协商,所以这里我使用了 ContentNegotiationManagerFactoryBean,但只配置了一个 JSON 格式的视图。
为了避免中文乱码,这里设置了 StringHttpMessageConverter 默认编码格式为 UTF-8,然后将其设置为 RequestMappingHandlerAdapter 的消息转换器。
最后还需要再配置一个欢迎页,类似于 web.xmlwelcome-file-list - welcome-file,因为 Servlet 3.0 规范没有针对欢迎页的Java配置方案,所以目前只能在Java中这样配置,其效果类似于在XML版中配置 <mvc:redirect-view-controller path="/" redirect-url="/index.html"/>
最后注意这里的 @Bean 注解,默认的 name 是方法名。

package org.xueliang.loginsecuritybyredis.commons;

import java.nio.charset.Charset;
import java.util.Collections;
import java.util.Properties;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.http.MediaType;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.web.accept.ContentNegotiationManager;
import org.springframework.web.accept.ContentNegotiationManagerFactoryBean;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter;
import org.springframework.web.servlet.view.ContentNegotiatingViewResolver;

@Configuration
@EnableWebMvc
@ComponentScan(basePackages = "org.xueliang.loginsecuritybyredis")
@PropertySource({"classpath:loginsecuritybyredis.properties"})
public class WebAppConfig extends WebMvcConfigurerAdapter {

    /**
     * 内容协商
     * @return
     */
    @Bean
    public ContentNegotiationManager mvcContentNegotiationManager() {
        ContentNegotiationManagerFactoryBean contentNegotiationManagerFactoryBean = new ContentNegotiationManagerFactoryBean();
        contentNegotiationManagerFactoryBean.setFavorParameter(true);
        contentNegotiationManagerFactoryBean.setIgnoreAcceptHeader(true);
        contentNegotiationManagerFactoryBean.setDefaultContentType(MediaType.APPLICATION_JSON_UTF8);
        Properties mediaTypesProperties = new Properties();
        mediaTypesProperties.setProperty("json", MediaType.APPLICATION_JSON_UTF8_VALUE);
        contentNegotiationManagerFactoryBean.setMediaTypes(mediaTypesProperties);
        contentNegotiationManagerFactoryBean.afterPropertiesSet();
        return contentNegotiationManagerFactoryBean.getObject();
    }

    @Bean
    public ContentNegotiatingViewResolver contentNegotiatingViewResolver(@Autowired ContentNegotiationManager mvcContentNegotiationManager) {
        ContentNegotiatingViewResolver contentNegotiatingViewResolver = new ContentNegotiatingViewResolver();
        contentNegotiatingViewResolver.setOrder(1);
        contentNegotiatingViewResolver.setContentNegotiationManager(mvcContentNegotiationManager);
        return contentNegotiatingViewResolver;
    }

    /**
     * 采用UTF-8编码,防止中文乱码
     * @return
     */
    @Bean
    public StringHttpMessageConverter stringHttpMessageConverter() {
        return new StringHttpMessageConverter(Charset.forName("UTF-8"));
    }

    @Bean
    public RequestMappingHandlerAdapter requestMappingHandlerAdapter(@Autowired StringHttpMessageConverter stringHttpMessageConverter) {
        RequestMappingHandlerAdapter requestMappingHandlerAdapter = new RequestMappingHandlerAdapter();
        requestMappingHandlerAdapter.setMessageConverters(Collections.singletonList(stringHttpMessageConverter));
        return requestMappingHandlerAdapter;
    }

    /**
     * 设置欢迎页
     * 相当于web.xml中的 welcome-file-list > welcome-file
     */
    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        registry.addRedirectViewController("/", "/index.html");
    }
}

编写登录认证Api

这里在 init 方法中初始化几个用户,放入 USER_DATA 集合,用于后续模拟登录。然后初始化 jedis 连接信息。init 方法被 @PostConstruct 注解,因此 Spring 创建该类的对象后,将自动执行其 init 方法,进行初始化操作。
然后看 login 方法,首先根据用户名获取最近 MAX_DISABLED_SECONDS 秒内失败的次数,是否超过最大限制 MAX_TRY_COUNT

若超过最大限制,不再对用户名和密码进行认证,直接返回认证失败提示信息,也即账户已被锁定的提示信息。

否则,进行用户认证。

若认证失败,将其添加到 Redis 缓存中,并设置过期默认为 MAX_DISABLED_SECONDS,表示从此刻起,MAX_DISABLED_SECONDS 秒内,该用户已登录失败 count 次。

若Redis缓存中已存在该用户认证失败的计数信息,则刷新 count 值,并将旧值的剩余存活时间设置到新值上,然后返回认证失败提示信息。

否则,返回认证成功提示信息。

package org.xueliang.loginsecuritybyredis.web.controller.api;

import java.util.HashMap;
import java.util.Map;

import javax.annotation.PostConstruct;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.xueliang.loginsecuritybyredis.web.model.JSONResponse;
import org.xueliang.loginsecuritybyredis.web.model.User;

import redis.clients.jedis.Jedis;

/**
 * 认证类
 * @author XueLiang
 * @date 2016年11月1日 下午4:11:59
 * @version 1.0
 */
@RestController
@RequestMapping("/api/auth/")
public class AuthApi {

    private static final Map<String, User> USER_DATA = new HashMap<String, User>();
    @Value("${auth.max_try_count}")
    private int MAX_TRY_COUNT = 0;
    @Value("${auth.max_disabled_seconds}")
    private int MAX_DISABLED_SECONDS = 0;

    @Value("${redis.host}")
    private String host;
    @Value("${redis.port}")
    private int port;
    private Jedis jedis;

    @PostConstruct
    public void init() {
        for (int i = 0; i < 3; i++) {
            String username = "username" + 0;
            String password = "password" + 0;
            USER_DATA.put(username + "_" + password, new User(username, "nickname" + i));
        }
        jedis = new Jedis(host, port);
    }

    @RequestMapping(value = {"login"}, method = RequestMethod.POST)
    public String login(@RequestParam("username") String username, @RequestParam("password") String password) {
        JSONResponse jsonResponse = new JSONResponse();
        String key = username;
        String countString = jedis.get(key);
        boolean exists = countString != null;
        int count = exists ? Integer.parseInt(countString) : 0;
        if (count >= MAX_TRY_COUNT) {
            checkoutMessage(key, count, jsonResponse);
            return jsonResponse.toString();
        }
        User user = USER_DATA.get(username + "_" + password);
        if (user == null) {
            count++;
            int secondsRemain = MAX_DISABLED_SECONDS;
            if (exists && count < 5) {
                secondsRemain = (int)(jedis.pttl(key) / 1000);
            }
            jedis.set(key, count + "");
            jedis.expire(key, secondsRemain);
            checkoutMessage(key, count, jsonResponse);
            return jsonResponse.toString();
        }
        count = 0;
        if (exists) {
            jedis.del(key);
        }
        checkoutMessage(key, count, jsonResponse);
        return jsonResponse.toString();
    }

    /**
     * 
     * @param key
     * @param count 尝试次数,也可以改为从redis里直接读
     * @param jsonResponse
     * @return
     */
    private void checkoutMessage(String key, int count, JSONResponse jsonResponse) {
        if (count == 0) {
            jsonResponse.setCode(0);
            jsonResponse.addMsg("success", "恭喜,登录成功!");
            return;
        }
        jsonResponse.setCode(1);
        if (count >= MAX_TRY_COUNT) {
            long pttlSeconds = jedis.pttl(key) / 1000;
            long hours = pttlSeconds / 3600;
            long sencondsRemain = pttlSeconds - hours * 3600;
            long minutes = sencondsRemain / 60;
            long seconds = sencondsRemain - minutes * 60;
            jsonResponse.addError("login_disabled", "登录超过" + MAX_TRY_COUNT + "次,请" + hours + "小时" + minutes + "分" + seconds + "秒后再试!");
            return;
        }
        jsonResponse.addError("username_or_password_is_wrong", "密码错误,您还有 " + (MAX_TRY_COUNT - count) + " 次机会!");
    }
}

编写前端页面

页面很简单,监听表单提交事件,用 ajax 提交表单数据,然后将认证结果显示到 div 中。

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>登录</title>
<style>
  span.error {
    color: red;
  }
  span.msg {
    color: green;
  }
</style>
</head>
<body>
<form action="" method="post">
  <label>用户名</label><input type="text" name="username">
  <label>密码</label><input type="text" name="password">
  <button type="submit">登录</button>
  <div></div>
</form>

<script>
  (function($) {
    var $ = (selector) => document.querySelector(selector);
    var xhr = new XMLHttpRequest();
    xhr.onreadystatechange = function() {
      if (this.readyState == 4 && this.status == 200) {
        var response = JSON.parse(this.responseText);
        var html = '';
        var msgNode = '';
        if (response.code != 0) {
          msgNode = 'error';
        } else {
          msgNode = 'msg';
        }
        for (var key in response[msgNode]) {
          html += '<span class="' + msgNode + '">' + response[msgNode][key] + '</span>';
        }
        $('div').innerHTML = html;
      }
    }

    var ajax = function(formData) {
      xhr.open('POST', '/api/auth/login.json', true);
      xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset=UTF-8'); // 将请求头设置为表单方式提交
      xhr.send(formData);
    }
    $('form').addEventListener('submit', function(event) {
      event.preventDefault();
      var formData = '';
      for (var elem of ['username', 'password']) {
        var value = $('input[name="' + elem + '"]').value;
        formData += (elem + '=' + value + '&');
      }
      ajax(formData);
    });
  })();
</script>
</body>
</html>

源码

最后上下源码地址:https://github.com/liangzai-cool/loginsecuritybyredis

更新

2016年11月29日 更新,代码优化,增加原子操作,org.xueliang.loginsecuritybyredis.web.controller.api.AuthApi#login 函数作如下优化:

    @RequestMapping(value = {"login"}, method = RequestMethod.POST)
    public String login(@RequestParam("username") String username, @RequestParam("password") String password) {
        JSONResponse jsonResponse = new JSONResponse();
        String key = username;
        String countString = jedis.get(key);
        boolean exists = countString != null;
        int count = exists ? Integer.parseInt(countString) : 0;
        if (count >= MAX_TRY_COUNT) {
            checkoutMessage(key, count, jsonResponse);
            return jsonResponse.toString();
        }
        User user = USER_DATA.get(username + "_" + password);
        if (user == null) {
            count++;
//            int secondsRemain = MAX_DISABLED_SECONDS;
//            if (exists && count < 5) {
//                secondsRemain = (int)(jedis.pttl(key) / 1000);
//            }
//            jedis.set(key, count + "");
//            jedis.expire(key, secondsRemain);
            if (exists) {
                jedis.incr(key);
                if (count >= MAX_TRY_COUNT) {
                    jedis.expire(key, MAX_DISABLED_SECONDS);
                }
            } else {
                jedis.set(key, count + "");
                jedis.expire(key, MAX_DISABLED_SECONDS);
            }
            checkoutMessage(key, count, jsonResponse);
            return jsonResponse.toString();
        }
        count = 0;
        if (exists) {
            jedis.del(key);
        }
        checkoutMessage(key, count, jsonResponse);
        return jsonResponse.toString();
    }

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