Shiro入门学习之自定义Realm实现授权（五）

一、自定义Realm授权

　　前提：认证通过，查看Realm接口的继承关系结构图如下，要想通过自定义的Realm实现授权，只需继承AuthorizingRealm并重写方法即可

二、实现过程

1、新建module，添加如下pom依赖

<properties>
        <shiro.version>1.4.1</shiro.version>
        <loggingg.version>1.2</loggingg.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.apache.shiro</groupId>
            <artifactId>shiro-core</artifactId>
            <version>${shiro.version}</version>
        </dependency>
        <dependency>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging</artifactId>
            <version>${loggingg.version}</version>
        </dependency>
    </dependencies>

2、新建UserRealm类继承AuthorizingRealm，重写方法

public class UserRealm extends AuthorizingRealm {
    private UserService userService = new UserServiceImpl();
    private RoleService roleService = new RoleServiceImpl();
    private PermissionService permissionService = new PermissionServiceImpl();

    /**
     * 做认证
     *
     * @param token
     * @return
     * @throws AuthenticationException
     */
    protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken token) throws AuthenticationException {
        String username = token.getPrincipal().toString();
        System.out.println("自定义Realm:" + username);
        User user = userService.queryUserByUserName(username);
        if (user != null) {
            List<String> roles = roleService.queryRoleByUserName(username);
            List<String> permissions = permissionService.queryPermissionByUserName(username);
            ActivityUser activityUser = new ActivityUser(user, roles, permissions);
            //参数1：可以传任意对象|参数2：数据库中的用户密码|参数3：当前类名
            SimpleAuthenticationInfo info = new SimpleAuthenticationInfo(activityUser, user.getPwd(), this.getName());
            return info;
        } else {
            return null;
        }
    }

    //授权方法
    protected AuthorizationInfo doGetAuthorizationInfo(PrincipalCollection principal) {
        SimpleAuthorizationInfo info = new SimpleAuthorizationInfo();
        System.out.println("doGetAuthorizationInfo被回调了");
        //
        Object primaryPrincipal = principal.getPrimaryPrincipal();
        System.out.println(primaryPrincipal);

        ActivityUser activityUser = (ActivityUser) principal.getPrimaryPrincipal();
        List<String> roles = activityUser.getRoles();
        if (roles != null && roles.size() > 0) {
            info.addRoles(roles);
        }
        List<String> permissins = activityUser.getPermissins();
        if (permissins!=null&&permissins.size()>0)
        {
            info.addStringPermissions(permissins);
        }
        //判断如果是超级管理员
        //info.addStringPermission("*:*");
        return info;
    }

3、test类测试方法

public class TestAuthorizationRealm
{
    public static void main(String[] args)
    {
        //1.模拟前台传递的用户名和密码
        String username = "zhangsan";
        String password = "123456";
        //2.创建安全管理器的工厂
        Factory<SecurityManager> factory = new IniSecurityManagerFactory("classpath:shiro.ini");
        //3.通过安全管理器工厂获取安全管理器
        DefaultSecurityManager securityManager = (DefaultSecurityManager)factory.getInstance();
        //4.创建自定义的Realm
        UserRealm userRealm = new UserRealm();
        //5.设置自定义的Realm
        securityManager.setRealm(userRealm);
        //6.将安全管理器绑定到当前运行环境
        SecurityUtils.setSecurityManager(securityManager);
        //7.从当前环境中获取Subject主体
        Subject subject1 = SecurityUtils.getSubject();
        //8.调用主体的登录方法
        try
        {
            subject1.login(new UsernamePasswordToken(username,password));
            System.out.println("登录成功~");

//            Object principal = subject1.getPrincipal();
//            System.out.println(principal);

        } catch (IncorrectCredentialsException e) {
            System.out.println("密码不正确");
        }catch (UnknownAccountException e) {
            System.out.println("用户名不存在");
        }

        boolean role1 = subject1.hasRole("role1");
        boolean role2 = subject1.hasRole("role1");
        System.out.println(role1);

        boolean permitted = subject1.isPermitted("user:add");
        System.out.println(permitted);
    }
}

三、分析

1、在进行授权的时候，每进行一次授权都会进行一次回调自定义Realm的doGetAuthorizationInfo方法，验证如下：

①在授权方法内部打印日志

②test类做3次授权，查看控制台如下：

2、认证时候进行查库，查角色、权限，并封装对象，避免多次调用授权方法导致频繁查库导致性能下降

四、总结

1、每次进行授权时，就会调用授权方法（通过打印日志可以验证）

2、避免在授权回调方法中查库而导致性能下降

3、授权方法参数可以获取到认证方法中放入的第一个任意参数（图中有说明，当然也可以通过subject.getPrincipal()方法获取该参数），所以我采用封装的方式，实现多次调用授权方法时也是同一个对象，避免频繁查库