下面来通过一个实例讲解Session认证的方式

创建工程：

  Spring Security二:Session的认证方式_第1张图片

引入依赖：



    

        org.springframework

        spring-webmvc

        5.0.4.RELEASE

    

    

        javax.servlet

        javax.servlet-api

        3.1.0

    

    

        org.projectlombok

        lombok

        1.18.8

    





    security‐springmvc

    

        

            

                org.apache.tomcat.maven

                tomcat7‐maven‐plugin

                2.2

            

            

                org.apache.maven.plugins

                maven‐compiler‐plugin

                

                    1.8

                    1.8

                

            

            

                maven‐resources‐plugin

                

                    utf‐8

                    true

                    

                        

                            src/main/resources

                            true

                            

                                **/*

                            

                        

                        

                            src/main/java

                            

                                **/*.xml

                            

                        

                    

                

            

        

    



Spring容器配置

在config包下定义ApplicationConfig.java，这个配置类相当于spring的配置文件

@Configuration
@ComponentScan(basePackages = ,excludeFilters = {@ComponentScan.Filter(type = FilterType.ANNOTATION,value = Controller.)})ApplicationConfig {

    }

在config包下定义WebConfig.java,这个配置类相当于springmv的配置文件

@Configuration @EnableWebMvc

@ComponentScan(basePackages = "cn.xh"

        ,includeFilters = {@ComponentScan.Filter(type = FilterType.ANNOTATION,value = Controller.class)})public class WebConfig implements WebMvcConfigurer {



   

    //视频解析器

    @Bean

    public InternalResourceViewResolver viewResolver(){

        InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();

        viewResolver.setPrefix("/WEB-INF/view/");

        viewResolver.setSuffix(".jsp");

        return viewResolver;

    }

}

加载spring容器

在init包下定义spring容器的初始化类SpringApplicationInitializer,该类实现了WebApplicationInitializer接口相当于web.xml文件。Spring容器启动时会加载所有实现了WebApplicationInitializer接口的类。
public class SpringApplicationInitializer extends

        AbstractAnnotationConfigDispatcherServletInitializer {

    @Override

    protected Class[] getRootConfigClasses() {

        return new Class[] { ApplicationConfig.class };    } @

            Override

    protected Class[] getServletConfigClasses() {

        return new Class[] { WebConfig.class };     } @

            Override

    protected String[] getServletMappings() {

        return new String [] {"/"};

    }

}
该类对应的web.xml文件可以参考：

org.springframework.web.context.ContextLoaderListener
 
  
 
  
contextConfigLocation
 
  
/WEB‐INF/application‐context.xml
 
  
 
  
 
  
springmvc
 
  
org.springframework.web.servlet.DispatcherServlet
 
  
 
  
contextConfigLocation
 
  
/WEB‐INF/spring‐mvc.xml
 
  
 
  
1
 
  
 
  
 
  
springmvc
 
  
/
 
  
 
  
 
  

 
  
实现认证功能
 
  
在webapp/WEB-INF/views下定义认证页面login.jsp
 
  
<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<html>
<head>
    <title>用户登录title>
head>
<body>
<form action="login" method="post">
    用户名：<input type="text" name="username"><br>
    密   码:
    <input type="password" name="password"><br>
    <input type="submit" value="登录">
form>
body>
html>
 
  
在WebConfig中新增如下配置，将/直接导向login.jsp页面：
 
  
@Override
public void addViewControllers(ViewControllerRegistry registry) {
    registry.addViewController("/").setViewName("login");
}
 
  

 
  
启动项目，访问/路径地址，进行测试
 
  
创建认证接口;
 
  
认证接口用来对传入的用户名和密码进行验证，验证成功返回用户的详细信息，失败抛出错误异常。
 
  
public interface AuthenticationService {
    /**
     * 用户认证
     * @param authenticationRequest 用户认证请求
     * @return 认证成功的用户信息
     */
    UserDto authentication(AuthenticationRequest authenticationRequest);
}
 
  

 
  
认证请求结构：
 
  
@Data
public class AuthenticationRequest {
    /**
     * 用户名
     */
    private String username;
    /**
     * 密码
     */
    private String password;
}
 
  

 
  
用户详细信息：
 
  
@Data
@AllArgsConstructor
public class UserDto {
    private String id;
    private String username;
    private String password;
    private String fullname;
    private String mobile;
}
 
  

 
  
认证实现类：
 
  
@Service
public class AuthenticationServiceImpl implements AuthenticationService {
    @Override
    public UserDto authentication(AuthenticationRequest authenticationRequest) {
        if(authenticationRequest == null
                || StringUtils.isEmpty(authenticationRequest.getUsername())
                || StringUtils.isEmpty(authenticationRequest.getPassword())){
            throw new RuntimeException("账号或密码为空");
        }
        UserDto userDto = getUserDto(authenticationRequest.getUsername());
        if(userDto == null){
            throw new RuntimeException("查询不到该用户");
        }
        if(!authenticationRequest.getPassword().equals(userDto.getPassword())){
            throw new RuntimeException("账号或密码错误");
        }
        return userDto;
    }
    //模拟用户查询
    public UserDto getUserDto(String username){
        return userMap.get(username);
    }
    //用户信息
    private Map userMap = new HashMap<>();
    {
        userMap.put("zhangsan",new UserDto("1010","zhangsan","123","张三","133443"));
        userMap.put("lisi",new UserDto("1011","lisi","456","李四","144553"));
    }
}
 
  

 
  
登录controller:
 
  
@RestController
public class LoginController {
    @Autowired
    private AuthenticationService authenticationService;
    /**
     * 用户登录
     * @param authenticationRequest 登录请求
     * @return
     */
    @PostMapping(value = "/login",produces = "text/plain;charset=utf‐8")   
 
  
public String login(AuthenticationRequest authenticationRequest){
        UserDto userDto = authenticationService.authentication(authenticationRequest);
        return userDto.getFullname() + " 登录成功";
    }
}
 
  
测试
 
  

 
  

 
  
实现会话功能：
 
  
当用户登录系统后，系统需要记住用户的信息，一般会把用户的信息放在session中，在需要的时候从session中获取用户的信息，这就是会话机制。
 
  
     
   
  1. 首先在UserDto中定义一个Session_USER_KEY,作为session的key
    2.  
  
 
  
public static final String SESSION_USER_KEY = "_user";
 
  
     
   
  1. 修改LoginController,认证成功后，将用户的信息放入session,并增加用户注销的方法，用户注销时清空session
    2.  
  
 
  
@PostMapping(value = "/login",produces = "text/plain;charset=utf‐8")
    public String login(AuthenticationRequest authenticationRequest, HttpSession session){
        UserDto userDto = authenticationService.authentication(authenticationRequest);
//用户信息存入session
        session.setAttribute(UserDto.SESSION_USER_KEY,userDto);
        return userDto.getUsername() + "登录成功";
    }

    @GetMapping(value = "logout",produces = "text/plain;charset=utf‐8")
    public String logout(HttpSession session){
        session.invalidate();
        return "退出成功";
    }
 
  
     
   
  1. 增加测试资源，在LoginController中增加测试资源：
    2.  
  
 
  

 
  
@GetMapping(value = "/r/r1",produces = {"text/plain;charset=utf-8"})
public String r1(HttpSession session){
    String fullname = null;
    Object userObj = session.getAttribute(UserDto.SESSION_USER_KEY);
    if(userObj != null){
        fullname = ((UserDto)userObj).getFullname();
    }else{
        fullname = "匿名";
    }
    return fullname + " 访问资源1";
}
 
  
     
   
  1. 测试：
    2.  
  
 
  
未登录访问 /r/r1显示：
 
  
Spring Security二:Session的认证方式_第2张图片
 
  
已登录访问 /r/r1显示：
 
  
Spring Security二:Session的认证方式_第3张图片
 
  
 实现授权功能
 
  
用户访问系统需要经过授权，需要完成如下功能：
 
  
     
   
  1. 禁止未登录用户访问某些资源
    2.  
   
  2. 登录用户根据用户的权限决定是否能访问某些资源
    3.  
  
 
  

 
  
第一步：在UserDto里增加权限属性表示该登录用户拥有的权限：
 
  
@Data
@AllArgsConstructor
public class UserDto {
    public static final String SESSION_USER_KEY = "_user";
    private String id;
    private String username;
    private String password;
    private String fullname;
    private String mobile;
    /**
     * 用户权限
     */
    private Set authorities;
}
 
  
第二步：在AuthenticationServiceImpl中为用户初始化权限，张三给了p1权限，李四给了p2权限：
 
  
//用户信息
private Map userMap = new HashMap<>();
{
    Set authorities1 = new HashSet<>();
    authorities1.add("p1");
    Set authorities2 = new HashSet<>();
    authorities2.add("p2");
    userMap.put("zhangsan",new UserDto("1010","zhangsan","123","张三","133443",authorities1));
            userMap.put("lisi",new UserDto("1011","lisi","456","李四","144553",authorities2));

}
 
  
第三步：在LoginController中增加测试资源：
 
  
/**
 * 测试资源2
 * @param session
 * @return
 */
@GetMapping(value = "/r/r2",produces = {"text/plain;charset=utf-8"})
public String r2(HttpSession session){
    String fullname = null;
    Object userObj = session.getAttribute(UserDto.SESSION_USER_KEY);
    if(userObj != null){
        fullname = ((UserDto)userObj).getFullname();
    }else{
        fullname = "匿名";
    }
    return fullname + " 访问资源2";
}
 
  
第四步：在interceptor包下实现授权拦截器SimpleAuthenticationInterceptor：
 
  
     
   
  1. 校验用户是否登录
    2.  
   
  2. 校验用户是否有操作权限
    3.  
  
 
  
@Component
 
  
public class SimpleAuthenticationInterceptor implements HandlerInterceptor {
    //请求拦截方法
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object
            handler) throws Exception {
//读取会话信息
        Object object = request.getSession().getAttribute(UserDto.SESSION_USER_KEY);
        if (object == null) {
            writeContent(response, "请登录");
        }
        UserDto user = (UserDto) object;
//请求的url
        String requestURI = request.getRequestURI();
        if (user.getAuthorities().contains("p1") && requestURI.contains("/r1")) {
            return true;
        }
        if (user.getAuthorities().contains("p2") && requestURI.contains("/r2")) {
            return true;
        }
        writeContent(response, "权限不足，拒绝访问");
        return false;
    }

    //响应输出
    private void writeContent(HttpServletResponse response, String msg) throws IOException {
        response.setContentType("text/html;charset=utf-8");
        PrintWriter writer = response.getWriter();
        writer.print(msg);
        writer.close();
        response.resetBuffer();
    }
}
 
  

 
  

 
  
在WebConfig中配置拦截器，配置/r/**的资源被拦截器处理：
 
  
@Autowired
private SimpleAuthenticationInterceptor simpleAuthenticationInterceptor;
@Override
public void addInterceptors(InterceptorRegistry registry) {
    registry.addInterceptor(simpleAuthenticationInterceptor).addPathPatterns("/r/**");
}
 
  

 
  
测试：
 
  
未登录：
 
  
Spring Security二:Session的认证方式_第4张图片
 
  

 
  
张三访问/r/r1：
 
  
Spring Security二:Session的认证方式_第5张图片
 
  
张三访问 /r/r2:
 
  
Spring Security二:Session的认证方式_第6张图片
 
  
我们通过session会话的方式实现了简单的认证和授权，但是在企业中我们往往会使用第三方的框架如：shiro和spring security来帮我们提高开发效率。