上两篇Shiro的认证要么写死在ini里，要么写死在realm里，这样很不灵活，开发过程中，角色和权限都是写在数据库里的，这时就需要用到JdbcRealm

JdbcRealm的用法十分简单，只要表名，表结构符合要求即可

先执行sql语句创建数据库，数据表和填充数据

drop database if exists shiro;
create database shiro;
use shiro;

create table users (
  id bigint auto_increment,
  username varchar(100),
  password varchar(100),
  password_salt varchar(100),
  constraint pk_users primary key(id)
) charset=utf8 ENGINE=InnoDB;
create unique index idx_users_username on users(username);

create table user_roles(
  id bigint auto_increment,
  username varchar(100),
  role_name varchar(100),
  constraint pk_user_roles primary key(id)
) charset=utf8 ENGINE=InnoDB;
create unique index idx_user_roles on user_roles(username, role_name);

create table roles_permissions(
  id bigint auto_increment,
  role_name varchar(100),
  permission varchar(100),
  constraint pk_roles_permissions primary key(id)
) charset=utf8 ENGINE=InnoDB;
create unique index idx_roles_permissions on roles_permissions(role_name, permission);

insert into users(username, password, password_salt) values('jack', '123456', null);
insert into user_roles(username, role_name) values('jack', 'role1');
insert into user_roles(username, role_name) values('jack', 'role2');
insert into roles_permissions(role_name, permission) values('role1', 'user1:*');
insert into roles_permissions(role_name, permission) values('role1', 'user2:*');
insert into roles_permissions(role_name, permission) values('role2', 'user3:*');

POM

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.jk.shiroLearning</groupId>
    <artifactId>chapter3</artifactId>
    <version>1.0-SNAPSHOT</version>
    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.9</version>
        </dependency>
        <dependency>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging</artifactId>
            <version>1.1.3</version>
        </dependency>
        <dependency>
            <groupId>org.apache.shiro</groupId>
            <artifactId>shiro-core</artifactId>
            <version>1.2.2</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.25</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>0.2.23</version>
        </dependency>


    </dependencies>

</project>

因为要用到数据库，所以要引入mysql-connector-java，还要引入druid作为连接池

Shiro.ini

[main]
authorizer=org.apache.shiro.authz.ModularRealmAuthorizer
securityManager.authorizer=$authorizer

#自定义realm 一定要放在securityManager.authorizer赋值之后（因为调用setRealms会将realms设置给authorizer，并给各个Realm设置permissionResolver和rolePermissionResolver）
jdbcRealm=org.apache.shiro.realm.jdbc.JdbcRealm
dataSource=com.alibaba.druid.pool.DruidDataSource
dataSource.driverClassName=com.mysql.jdbc.Driver
dataSource.url=jdbc:mysql://localhost:3306/shiro
dataSource.username=root
dataSource.password=root
jdbcRealm.dataSource=$dataSource
jdbcRealm.permissionsLookupEnabled=true
securityManager.realms=$jdbcRealm

验证登录和身份信息

public class TestJdbcRealm {
    public static void main(String[]args){
        //1、获取SecurityManager工厂，此处使用Ini配置文件初始化SecurityManager
        Factory<SecurityManager> factory =
                new IniSecurityManagerFactory("classpath:shiro.ini");

        //2、得到SecurityManager实例 并绑定给SecurityUtils
        org.apache.shiro.mgt.SecurityManager securityManager = factory.getInstance();
        SecurityUtils.setSecurityManager(securityManager);

        //3、得到Subject及创建用户名/密码身份验证Token（即用户身份/凭证）
        Subject subject = SecurityUtils.getSubject();
        UsernamePasswordToken token = new UsernamePasswordToken("jack", "123456");

        try {
            //4、登录，即身份验证
            subject.login(token);
            //验证是否有user1的create权限
            System.out.println(subject.isPermitted("user1:create:*"));
            //验证是否有role1角色
            System.out.println(subject.hasRole("role1"));
        } catch (AuthenticationException e) {
            //5、身份验证失败
            e.printStackTrace();
        }
        //6、退出
        subject.logout();
    }
}

JdbcRealm使用起来十分方便，只需传入帐号密码，认证和授权的方法都帮你实现好了

源码地址https://github.com/jkgeekJack/shiro-learning/tree/master/chapter3