CAS 界面根据不同的域名显示不同的界面

概要

在实际需求中，客户想通过不同的域名显示不同的登录界面，比如输入 manage.aps.cn 显示运维管理登录，business.aps.cn 显示业务管理登录。

实现方法

1.准备两套登录UI

在cas目录 WEB-INF/view/jsp目录下整两份UI。

增加两个属性文件，这些属性文件和UI有关系。

查看一下 business.properties

cas 默认显示界面是在cas.properties 文件中配置，配置完成后，不能再变更了，因此需要能够实现切换UI。

2.代码实现

我的思路是通过根据域名动态改变 这个basename。在过滤器中获取域名，并动态改变basename。

实现方式在过滤器中，判断当前的访问域名，判定需要访问哪个UI并进行切换。

修改源码：

org.springframework.web.servlet.view.ResourceBundleViewResolver，

这个代码原本是不能实现UI切换的。

package org.springframework.web.servlet.view;

import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.beans.factory.support.PropertiesBeanDefinitionReader;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.core.Ordered;
import org.springframework.web.context.support.GenericWebApplicationContext;
import org.springframework.web.servlet.View;

public class ResourceBundleViewResolver extends AbstractCachingViewResolver
  implements Ordered, InitializingBean, DisposableBean
{
  public static final String DEFAULT_BASENAME = "views";
  private int order = 2147483647;

  private  ThreadLocal<String>  baseNameLocal= new ThreadLocal<>();

  private ClassLoader bundleClassLoader = Thread.currentThread().getContextClassLoader();
  private String defaultParentView;
  private Locale[] localesToInitialize;
  private final Map<Locale, BeanFactory> localeCache = new HashMap();

  private final Map<List<ResourceBundle>, ConfigurableApplicationContext> bundleCache = new HashMap();

  public void setOrder(int order)
  {
    this.order = order;

  }

  public int getOrder() {
    return this.order;
  }

  public void setBasename(String basename)
  {
    this.baseNameLocal.set(basename);
  }

  public void setBundleClassLoader(ClassLoader classLoader)
  {
    this.bundleClassLoader = classLoader;
  }

  protected ClassLoader getBundleClassLoader()
  {
    return this.bundleClassLoader;
  }

  public void setDefaultParentView(String defaultParentView)
  {
    this.defaultParentView = defaultParentView;
  }

  public void setLocalesToInitialize(Locale[] localesToInitialize)
  {
    this.localesToInitialize = localesToInitialize;
  }

  public void afterPropertiesSet()
    throws BeansException
  {
    if (this.localesToInitialize != null)
      for (Locale locale : this.localesToInitialize)
        initFactory(locale);
  }

  protected View loadView(String viewName, Locale locale)
    throws Exception
  {
    BeanFactory factory = initFactory(locale);
    try {
      return (View)factory.getBean(viewName, View.class);
    }
    catch (NoSuchBeanDefinitionException ex) {
    }
    return null;
  }

  protected synchronized BeanFactory initFactory(Locale locale)
    throws BeansException
  {

    List<ResourceBundle> bundles = new LinkedList();

    String baseName="manage";

    if(this.baseNameLocal.get()!=null){
        baseName=this.baseNameLocal.get();
    }

    ResourceBundle bundle = getBundle(baseName, locale);
    bundles.add(bundle);

    GenericWebApplicationContext factory = new GenericWebApplicationContext();
    factory.setParent(getApplicationContext());
    factory.setServletContext(getServletContext());

    PropertiesBeanDefinitionReader reader = new PropertiesBeanDefinitionReader(factory);
    reader.setDefaultParentBean(this.defaultParentView);
    reader.registerBeanDefinitions(bundle);

    factory.refresh();

    return factory;
  }

  protected ResourceBundle getBundle(String basename, Locale locale)
    throws MissingResourceException
  {
    return ResourceBundle.getBundle(basename, locale, getBundleClassLoader());
  }

  public void destroy()
    throws BeansException
  {
    for (ConfigurableApplicationContext factory : this.bundleCache.values()) {
      factory.close();
    }
    this.localeCache.clear();
    this.bundleCache.clear();
  }
}

增加一个过滤器，根据域名修改 页面视图目录。

package com.redxun.cas;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

import org.springframework.web.servlet.view.ResourceBundleViewResolver;

public class ViewSelectFilter implements Filter{

    @Override
    public void destroy() {

    }

    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
            throws IOException, ServletException {
        HttpServletRequest request=(HttpServletRequest)req;
        ResourceBundleViewResolver resolver=(ResourceBundleViewResolver) SpringContextHolder.getBean("viewResolver");
        String serverName=request.getServerName();
        String pre=serverName.substring(0,serverName.indexOf("."));
        resolver.setBasename(pre);

        chain.doFilter(req, res);
    }

    @Override
    public void init(FilterConfig arg0) throws ServletException {

    }

}

修改 cas-servlet.xml配置。

<bean id="viewResolver"  class="org.springframework.web.servlet.view.ResourceBundleViewResolver"
        p:order="0">
    <property name="basename" value="${cas.viewResolver.basename}" />
    <property name="cache" value="false"></property>
  </bean>

配置过滤器

<filter>
       <filter-name>ViewSelectFilter</filter-name>
       <filter-class>com.redxun.cas.ViewSelectFilter</filter-class>
   </filter>

  <filter-mapping>
        <filter-name>ViewSelectFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

测试效果

在host添加域名映射

192.168.1.77 manage.aps.cn
192.168.1.77 business.aps.cn

测试效果如下：

访问：manage.aps.cn

business.aps.cn

另外一个知识点，我们在过滤器中需要获取，spring mvc的上下文。

我们需要实现一个获取上下文的类。实现接口：ApplicationContextAware

package com.redxun.cas;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;

public class SpringContextHolder implements ApplicationContextAware {
    private static ApplicationContext _ctx;

    @Override
    public void setApplicationContext(ApplicationContext ctx) throws BeansException {
        _ctx=ctx;
    }
    public static Object getBean(String beanId){
        return _ctx.getBean(beanId);
    }
    public static Object getBean(Class cls){
        return _ctx.getBean(cls);
    }
}

这里配置也是有要求的需要配置 cas-servlet.xml配置文件中。

配置如下：

<bean id="springContextHolder" class="com.redxun.cas.SpringContextHolder"></bean>