關於shiro我就不說了，公司的用到shiro這兩天看了下，又重新認知了一遍使用者角色許可權之間的關係，在看shiro和web整合的時候，關於驗證流程這一塊記錄一下。
這裡直接寫驗證流程了：關於配置就不說了，這是與資料庫互動的shiro要依賴service層,嗯 先看是怎麼驗證的
瞭解shiro之後呢，我們都是自己去實現一個realm重寫認證和許可權函式（這裡只說登入）。程式碼如下：

public class ShiroDbRealm extends AuthorizingRealm {

    protected AccountService accountService;

    /**
     * 認證回撥函式,登入時呼叫.
     */
 

    @Override
    protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken authcToken) throws AuthenticationException {
        UsernamePasswordToken token = (UsernamePasswordToken) authcToken;
        User user = accountService.findUserByLoginName(token.getUsername());
        if (user != null
 
) {
            byte[] salt = Encodes.decodeHex(user.getSalt());
                  return new SimpleAuthenticationInfo(new ShiroUser(user.getId(), user.getLoginName(), user.getName()),
                    user.getPassword(), ByteSource.Util.bytes(salt), getName());
        } else {
                  return
 
 null;
        }
    }

    /**
     * 授權查詢回撥函式, 進行鑑權但快取中無使用者的授權資訊時呼叫.
     */
    @Override
    protected AuthorizationInfo doGetAuthorizationInfo(PrincipalCollection principals) {
        ShiroUser shiroUser = (ShiroUser) principals.getPrimaryPrincipal();
        User user = accountService.findUserByLoginName(shiroUser.loginName);
        SimpleAuthorizationInfo info = new SimpleAuthorizationInfo();
        info.addRoles(user.getRoleList());
        return info;
    }

    /**
     * 設定Password校驗的Hash演算法與迭代次數.
     */
    @PostConstruct
    public void initCredentialsMatcher() {
        HashedCredentialsMatcher matcher = new HashedCredentialsMatcher(AccountService.HASH_ALGORITHM);
        matcher.setHashIterations(AccountService.HASH_INTERATIONS);

        setCredentialsMatcher(matcher);//這裡把匹配器傳過去
    }

    public void setAccountService(AccountService accountService) {
        this.accountService = accountService;
    }

    /**
     * 自定義Authentication物件，使得Subject除了攜帶使用者的登入名外還可以攜帶更多資訊.
     */
    public static class ShiroUser implements Serializable {
        private static final long serialVersionUID = -1373760761780840081L;
        public Long id;
        public String loginName;
        public String name;

        public ShiroUser(Long id, String loginName, String name) {
            this.id = id;
            this.loginName = loginName;
            this.name = name;
        }

        public String getName() {
            return name;
        }

        /**
         * 本函式輸出將作為預設的<shiro:principal/>輸出.
         */
        @Override
        public String toString() {
            return loginName;
        }

        /**
         * 過載hashCode,只計算loginName;
         */
        @Override
        public int hashCode() {
            return Objects.hashCode(loginName);
        }

        /**
         * 過載equals,只計算loginName;
         */
        @Override
        public boolean equals(Object obj) {
            if (this == obj) {
                return true;
            }
            if (obj == null) {
                return false;
            }
            if (getClass() != obj.getClass()) {
                return false;
            }
            ShiroUser other = (ShiroUser) obj;
            if (loginName == null) {
                if (other.loginName != null) {
                    return false;
                }
            } else if (!loginName.equals(other.loginName)) {
                return false;
            }
            return true;
        }
    }
}

但看這裡可能會很迷茫，密碼驗證呢？

setCredentialsMatcher(matcher);//這裡把匹配器傳過去
在這裡看到傳了一個matcher於是我們繼續開啟這個方法的原始碼如下：

public abstract class AuthenticatingRealm extends CachingRealm implements Initializable {
................
 public void setCredentialsMatcher(CredentialsMatcher credentialsMatcher) {
        this.credentialsMatcher = credentialsMatcher;
    }
    ...........
protected void assertCredentialsMatch(AuthenticationToken token, AuthenticationInfo info) throws AuthenticationException {
        CredentialsMatcher cm = getCredentialsMatcher();
        if (cm != null) {
            if (!cm.doCredentialsMatch(token, info)) {
                //not successful - throw an exception to indicate this:
                String msg = "Submitted credentials for token [" + token + "] did not match the expected credentials.";
                throw new IncorrectCredentialsException(msg);
            }
        } else {
            throw new AuthenticationException("A CredentialsMatcher must be configured in order to verify " +
                    "credentials during authentication.  If you do not wish for credentials to be examined, you " +
                    "can configure an " + AllowAllCredentialsMatcher.class.getName() + " instance.");
        }

是這個抽象類AuthenticatingRealm的方法,再往下看getCredentialsMatcher();就看到了Info和token那麼就是資料的比較了
cm.doCredentialsMatch(token, info)
再往下看無非就是一些解密比較返回了

內部流程：
1.AuthenticatingRealm繼承CachingRealm執行getAuthenticationInfo

2.呼叫SimpleCredentialsMatcher的doCredentialsMatch()