Spring boot +Spring Security + Thymeleaf 認證失敗返回錯誤信息

 

[Please make sure to select the branch corresponding to the version of Thymeleaf you are using]

Status

This is a thymeleaf extras module, not a part of the Thymeleaf core (and as such following its own versioning schema), but fully supported by the Thymeleaf team.

This repository contains two projects:

• thymeleaf-extras-springsecurity3 for integration with Spring Security 3.x
• thymeleaf-extras-springsecurity4 for integration with Spring Security 4.x

Current versions:

• Version 3.0.2.RELEASE - for Thymeleaf 3.0 (requires Thymeleaf 3.0.3+)
• Version 2.1.3.RELEASE - for Thymeleaf 2.1 (requires Thymeleaf 2.1.2+)

License

This software is licensed under the [Apache License 2.0] (http://www.apache.org/licenses/LICENSE-2.0.html).

Requirements (3.0.x)

• Thymeleaf 3.0.0+
• Spring Framework version 3.0.x to 4.3.x
• Spring Security version 3.0.x to 4.2.x
• Web environment (Spring Security integration cannot work offline)

Maven info

• groupId: org.thymeleaf.extras
• artifactId:
• Spring Security 3 integration package: thymeleaf-extras-springsecurity3
• Spring Security 4 integration package: thymeleaf-extras-springsecurity4

Distribution packages

Distribution packages (binaries + sources + javadoc) can be downloaded from SourceForge.

Features

This module provides a new dialect called org.thymeleaf.extras.springsecurity3.dialect.SpringSecurityDialect or org.thymeleaf.extras.springsecurity4.dialect.SpringSecurityDialect (depending on the Spring Security version), with default prefix sec. It includes:

• New expression utility objects:
• #authentication representing the Spring Security authentication object (an object implementing the org.springframework.security.core.Authentication interface).
• #authorization: a expression utility object with methods for checking authorization based on expressions, URLs and Access Control Lists.
• New attributes:
• sec:authentication="prop" outputs a prop property of the authentication object, similar to the Spring Security <sec:authentication/> JSP tag.
• sec:authorize="expr" or sec:authorize-expr="expr" renders the element children (tag content) if the authenticated user is authorized to see it according to the specified Spring Security expression.
• sec:authorize-url="url" renders the element children (tag content) if the authenticated user is authorized to see the specified URL.
• sec:authorize-acl="object :: permissions" renders the element children (tag content) if the authenticated user has the specified permissions on the specified domain object, according to Spring Source's Access Control List system.

---

Configuration

In order to use the thymeleaf-extras-springsecurity3 or thymeleaf-extras-springsecurity4 modules in our Spring MVC application, we will first need to configure our application in the usual way for Spring + Thymeleaf applications (TemplateEngine bean, template resolvers, etc.), and add the SpringSecurity dialect to our Template Engine so that we can use the sec:* attributes and special expression utility objects:

    <bean id="templateEngine" class="org.thymeleaf.spring4.SpringTemplateEngine"> ... <property name="additionalDialects"> <set> <!-- Note the package would change to 'springsecurity3' if you are using that version --> <bean class="org.thymeleaf.extras.springsecurity4.dialect.SpringSecurityDialect"/> </set> </property> ... </bean>

And that's all!

Using the expression utility objects

The #authentication object can be easily used, like this:

    <div th:text="${#authentication.name}"> The value of the "name" property of the authentication object should appear here. </div>

The #authorization object can be used in a similar way, normally in th:if or th:unlesstags:

    <div th:if="${#authorization.expression('hasRole(''ROLE_ADMIN'')')}"> This will only be displayed if authenticated user has role ROLE_ADMIN. </div>

The #authorization object is an instance of org.thymeleaf.extras.springsecurity[3|4].auth.Authorization, see this class and its documentation to understand all the methods offered.

Using the attributes

Using the sec:authentication attribute is equivalent to using the #authentication object, but using its own attribute:

    <div sec:authentication="name"> The value of the "name" property of the authentication object should appear here. </div>

The sec:authorize and sec:authorize-expr attributes are exactly the same. They work equivalently to a th:if that evaluated an #authorization.expression(...) expression, by evaluating a Spring Security Expression:

    <div sec:authorize="hasRole('ROLE_ADMIN')"> This will only be displayed if authenticated user has role ROLE_ADMIN. </div>

These Spring Security Expressions in sec:authorize attributes are in fact Spring EL expressions evaluated on a SpringSecurity-specific root object containing methods such as hasRole(...), getPrincipal(), etc.

As with normal Spring EL expressions, Thymeleaf allows you to access a series of objects from them including the context variables map (the #vars object). In fact, you are allowed to surround your access expression with ${...} if it makes you feel more comfortable:

    <div sec:authorize="${hasRole(#vars.expectedRole)}"> This will only be displayed if authenticated user has a role computed by the controller. </div>

Remember that Spring Security sets a special security-oriented object as expression root, which is why you would not be able to access the expectedRole variable directly in the above expression.

Another way of checking authorization is sec:authorize-url, which allows you to check whether a user is authorized to visit a specific URL or not:

    <div sec:authorize-url="/admin"> This will only be displayed if authenticated user can call the "/admin" URL. </div>

For specifying a specific HTTP method, do:

    <div sec:authorize-url="POST /admin"> This will only be displayed if authenticated user can call the "/admin" URL using the POST HTTP method. </div>

Finally, there is an attribute for checking authorization using Spring Security's Access Control Lists, which needs the specification of a domain object and the permissions defined on it that we are asking for.

    <div sec:authorize-acl="${obj} :: '1,3'"> This will only be displayed if authenticated user has permissions "1" and "3" on domain object referenced by context variable "obj". </div>

In this attribute, both domain object and permission specifications are considered to be thymeleaf Standard Expressions.

Namespace

The namespace for both Spring 3 and 4 versions of this dialect is http://www.thymeleaf.org/extras/spring-security.

 <html xmlns:sec="http://www.thymeleaf.org/extras/spring-security">

Getting the namespace incorrect won't impact processing of your template. It might however impact your IDE when it comes to things like suggestions/auto-completion in your templates.

https://github.com/thymeleaf/thymeleaf-extras-springsecurity

 

 

spring boot以其眾多友誼的特性，如零配置、微服務等，吸引了很多的粉絲。而其與Spring Security安全框架的無縫結合，使其具備的安全的特性。在此基礎上使用Thymeleaf模板引擎進行渲染，靜動態結合，讓頁面開發更加簡單、直觀。

通過表單提交登錄的用戶名和密碼是登錄接口比較常見的一種設計。在初學的過程中，我也不例外的采用個這種方式。表單設計見下圖。

 

登錄成功，完成正常的主頁面跳轉，這個不存在問題。存在問題的是，登錄失敗了該咋辦呢？我就在考慮，由於thymeleaf的局部刷新操作，登錄失敗了將登錄失敗的異常信息顯示在登錄頁面，也就是表單上。於是，我的登錄設計又變成了如下圖所示的表單。

        

         通過這種方法，當登錄表單驗證失敗時，會該用戶顯示”用戶名或密碼錯誤，請重試”，這當然是比較好的，但是驗證失敗的情況不僅僅是用戶名或密碼錯誤吧，應該還有其它的情形，比較常見的就有，該用戶已被鎖定，該用戶不存在，請先注冊等。

那么該如何區分這么情形呢，怎么把登錄表單驗證失敗的比較詳細的狀況顯示給用戶呢。經過一段時間的調研，發現Spring boot提供了比較完美的解決方案，而其秘密就在Spring Security的配置中。我項目中的Spring Security配置如下圖所示。

 

而我在閱讀Spring Security源碼時，當認證失敗時，找尋到以下處理的代碼

 

而重點就在saveException函數，而此函數的具體代碼如下：

 

從這段代碼中，我們可以清晰的看到，認證失敗的異常信息被保存在Session中，如果我們可以讀取Session中的信息那么，之前所遇到的問題就迎刃而解了吧。

事實上，事物的發展從來不是一帆風順的，解決問題也是類似。我了解到Thymeleaf提供了讀取緩存Session的方案，就迫不及待的進行嘗試，於是乎，我的登錄表單又變成了如下模樣，紅線指出的是Thymleaf緩存的讀取方式。

 

這樣就可以顯示驗證失敗的具體信息了嗎？經過我的測試，我發現，此信息是未定義。也就是說，模樣讀取到緩存中的信息。

通過在網上查找資料，我在浩瀚的百度的犄角旮旯里，查找到以下的代碼片段。

 

         我如獲至寶，仿佛見到了光明。在配置文件配置的時代，可以設置登錄失敗的跳轉頁面為”/login.html?error=true”,而我設置的是“/login?error”，那么是否可以設置為類似的true呢？我迫不及待的進行嘗試。於是乎，我Spring Security的Java Config又變成了如下的樣子。

 

經過驗證，通過這樣設置，完美的解決了我遇到的問題，到現在，我仍沒有明白設置true的含義，望知道的讀者可以告訴小編。

小編來總結哈，在Spring boot +Spring Security + Thymeleaf框架下，通過用戶名/密碼表單提交，在登錄界面獲取異常信息的步驟，主要有以下兩點：

其一：將登錄失敗的url設置為”/login?error=true”(即后綴帶?error=true),使前端的thymleaf可以讀取Session；

其二：Thymeleaf提供的讀取緩存中信息的方法${session.SPRING_SECURITY_LAST_EXCEPTION.message}，兩者缺一不可。

 

http://blog.csdn.net/sun1021873926/article/details/60332059