spring boot自带spring security，spring security自然不用说是一个强大的安全框架，但是用惯了shiro，一时半会用不来spring security，所以要在spring boot中自己整合shiro。说到整合shiro，网上也是有不少教程的，但是网上的教程也不是一定是对的，可能有版本等各种问题，所以说还是要自己来动手做一遍。

　　在我动手整合的时候出现UnavailableSecurityManagerException的错误：

2016-12-24 10:58:56.787 ERROR 7916 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [org.apache.shiro.UnavailableSecurityManagerException: No SecurityManager accessible to the calling code, either bound to the org.apache.shiro.util.ThreadContext or as a vm static singleton.  This is an invalid application configuration.] with root cause

org.apache.shiro.UnavailableSecurityManagerException: No SecurityManager accessible to the calling code, either bound to the org.apache.shiro.util.ThreadContext or as a vm static singleton.  This is an invalid application configuration.

spring整合shiro出现UnavailableSecurityManagerException在网上查出的问题都是没有配置DelegatingFilterProxy或者DelegatingFilterProxy的配置顺序错了，对应的解决办法就是在web.xml上添加DelegatingFilterProxy。

<filter>
    <filter-name>shiroFilter</filter-name>
    <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
    <async-supported>true</async-supported>
    <init-param>
             <param-name>targetFilterLifecycle</param-name>
             <param-value>true</param-value>
     </init-param>
</filter>
<filter-mapping>
    <filter-name>shiroFilter</filter-name>
    <url-pattern>/*</url-pattern>
 </filter-mapping>

可是我们现在使用的spring boot啊，才不要再用回web.xml的配置文件呢。那到底怎么解决呢？

我第一想法就是，使用FilterRegistrationBean注册一个DelegatingFilterProxy：

@Bean
public FilterRegistrationBean delegatingFilterProxy(){
    FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
    DelegatingFilterProxy proxy = new DelegatingFilterProxy();
    proxy.setTargetFilterLifecycle(true);
    filterRegistrationBean.setFilter(proxy);
    return filterRegistrationBean;
}

跟上面一样，应该没问题吧？可这都是我的一厢情愿，出错了：

org.springframework.beans.factory.BeanNotOfRequiredTypeException: Bean named ‘delegatingFilterProxy‘ is expected to be of type [javax.servlet.Filter] but was actually of type [org.springframework.boot.web.servlet.FilterRegistrationBean]

at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:378) ~[spring-beans-4.3.3.RELEASE.jar:4.3.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-4.3.3.RELEASE.jar:4.3.3.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1082) ~[spring-context-4.3.3.RELEASE.jar:4.3.3.RELEASE]
    at org.springframework.web.filter.DelegatingFilterProxy.initDelegate(DelegatingFilterProxy.java:326) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]
    at org.springframework.web.filter.DelegatingFilterProxy.initFilterBean(DelegatingFilterProxy.java:235) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]
    at org.springframework.web.filter.GenericFilterBean.init(GenericFilterBean.java:199) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]
    at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:279) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
    at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:109) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
    at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4572) [tomcat-embed-core-8.5.5.jar:8.5.5]
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5215) [tomcat-embed-core-8.5.5.jar:8.5.5]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) [tomcat-embed-core-8.5.5.jar:8.5.5]
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1403) [tomcat-embed-core-8.5.5.jar:8.5.5]
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1393) [tomcat-embed-core-8.5.5.jar:8.5.5]
    at java.util.concurrent.FutureTask.run(FutureTask.java:266) [na:1.8.0_25]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_25]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_25]
    at java.lang.Thread.run(Thread.java:745) [na:1.8.0_25]

看到下面这个错误行：

at org.springframework.web.filter.DelegatingFilterProxy.initDelegate(DelegatingFilterProxy.java:326) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]

看到下面代码，我们大概可以知道，根据getTargetBeanName()来进行委派，而TargetBeanName是delegatingFilterProxy。

诶，不对啊，我shiroFilter的beanName不是这个啊，明明是shiroFilter。

protected Filter initDelegate(WebApplicationContext wac) throws ServletException {
     Filter delegate = wac.getBean(getTargetBeanName(), Filter.class);
     if (isTargetFilterLifecycle()) {
         delegate.init(getFilterConfig());
     }
     return delegate;
}

解决办法

经过上面一大串推论，解决办法就是：

@Bean
public FilterRegistrationBean delegatingFilterProxy(){
    FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
    DelegatingFilterProxy proxy = new DelegatingFilterProxy();
    proxy.setTargetFilterLifecycle(true);
    proxy.setTargetBeanName("shiroFilter");
    filterRegistrationBean.setFilter(proxy);
    return filterRegistrationBean;
}

@Bean("shiroFilter")
public ShiroFilterFactoryBean shiroFilterFactoryBean() {
    ShiroFilterFactoryBean filterFactoryBean = new ShiroFilterFactoryBean();
    .......
    return filterFactoryBean;
}

没有写太多shiro的整合代码，只写了解决UnavailableSecurityManagerException问题的关键代码，如需要可以自行网上查找。