程序包 cn.taketoday.web.servlet.filter

类 DelegatingFilterProxy

java.lang.Object

cn.taketoday.web.servlet.filter.GenericFilterBean

cn.taketoday.web.servlet.filter.DelegatingFilterProxy

所有已实现的接口:

cn.taketoday.beans.factory.Aware, cn.taketoday.beans.factory.BeanNameAware, cn.taketoday.beans.factory.DisposableBean, cn.taketoday.beans.factory.InitializingBean, cn.taketoday.context.EnvironmentAware, cn.taketoday.core.env.EnvironmentCapable, ServletContextAware, Filter

public class DelegatingFilterProxy
extends GenericFilterBean

Proxy for a standard Servlet Filter, delegating to a Frameworkmanaged bean that implements the Filter interface. Supports a "targetBeanName" filter init-param in web.xml, specifying the name of the target bean in the Framework application context.

web.xml will usually contain a DelegatingFilterProxy definition, with the specified filter-name corresponding to a bean name in Framework's root application context. All calls to the filter proxy will then be delegated to that bean in the Framework context, which is required to implement the standard Servlet Filter interface.

This approach is particularly useful for Filter implementation with complex setup needs, allowing to apply the full Framework bean definition machinery to Filter instances. Alternatively, consider standard Filter setup in combination with looking up service beans from the Framework root application context.

NOTE: The lifecycle methods defined by the Servlet Filter interface will by default not be delegated to the target bean, relying on the Framework application context to manage the lifecycle of that bean. Specifying the "targetFilterLifecycle" filter init-param as "true" will enforce invocation of the Filter.init and Filter.destroy lifecycle methods on the target bean, letting the servlet container manage the filter lifecycle.

DelegatingFilterProxy has been updated to optionally accept constructor parameters when using a Servlet container's instance-based filter registration methods These constructors allow for providing the delegate Filter bean directly, or providing the application context and bean name to fetch, avoiding the need to look up the application context from the ServletContext.

This class was originally inspired by Framework Security's FilterToBeanProxy class, written by Ben Alex.

从以下版本开始:

4.0 2022/2/20 23:17

作者:

Juergen Hoeller, Sam Brannen, Chris Beams, Harry Yang

另请参阅:

• setTargetBeanName(java.lang.String)
• setTargetFilterLifecycle(boolean)
• Filter.doFilter(jakarta.servlet.ServletRequest, jakarta.servlet.ServletResponse, jakarta.servlet.FilterChain)
• Filter.init(jakarta.servlet.FilterConfig)
• Filter.destroy()
• DelegatingFilterProxy(Filter)
• DelegatingFilterProxy(String)
• DelegatingFilterProxy(String, ApplicationContext)
• ServletContext.addFilter(String, Filter)

字段概要

字段

修饰符和类型	字段	说明
private cn.taketoday.context.ApplicationContext	applicationContext
private String	contextAttribute
private Filter	delegate
private final Object	delegateMonitor
private String	targetBeanName
private boolean	targetFilterLifecycle

从类继承的字段 cn.taketoday.web.servlet.filter.GenericFilterBean

logger

构造器概要

构造器

构造器	说明
DelegatingFilterProxy()	Create a new DelegatingFilterProxy.
DelegatingFilterProxy(Filter delegate)	Create a new DelegatingFilterProxy with the given Filter delegate.
DelegatingFilterProxy(String targetBeanName)	Create a new DelegatingFilterProxy that will retrieve the named target bean from the Framework WebApplicationContext found in the ServletContext (either the 'root' application context or the context named by setContextAttribute(java.lang.String)).
DelegatingFilterProxy(String targetBeanName, cn.taketoday.context.ApplicationContext wac)	Create a new DelegatingFilterProxy that will retrieve the named target bean from the given Framework WebApplicationContext.

方法概要

修饰符和类型	方法	说明
void	destroy()	Subclasses may override this to perform custom filter shutdown.
protected void	destroyDelegate(Filter delegate)	Destroy the Filter delegate.
void	doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain)
protected cn.taketoday.context.ApplicationContext	findApplicationContext()	Return the WebApplicationContext passed in at construction time, if available.
String	getContextAttribute()	Return the name of the ServletContext attribute which should be used to retrieve the WebApplicationContext from which to load the delegate Filter bean.
protected String	getTargetBeanName()	Return the name of the target bean in the Framework application context.
protected Filter	initDelegate(cn.taketoday.context.ApplicationContext wac)	Initialize the Filter delegate, defined as bean the given Framework application context.
protected void	initFilterBean()	Subclasses may override this to perform custom initialization.
protected void	invokeDelegate(Filter delegate, ServletRequest request, ServletResponse response, FilterChain filterChain)	Actually invoke the delegate Filter with the given request and response.
protected boolean	isTargetFilterLifecycle()	Return whether to invoke the Filter.init and Filter.destroy lifecycle methods on the target bean.
void	setContextAttribute(String contextAttribute)	Set the name of the ServletContext attribute which should be used to retrieve the WebApplicationContext from which to load the delegate Filter bean.
void	setTargetBeanName(String targetBeanName)	Set the name of the target bean in the Framework application context.
void	setTargetFilterLifecycle(boolean targetFilterLifecycle)	Set whether to invoke the Filter.init and Filter.destroy lifecycle methods on the target bean.

从类继承的方法 cn.taketoday.web.servlet.filter.GenericFilterBean

addRequiredProperty, afterPropertiesSet, createEnvironment, getEnvironment, getFilterConfig, getFilterName, getServletContext, init, initBeanWrapper, setBeanName, setEnvironment, setServletContext

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

字段详细资料

contextAttribute

@Nullable
private String contextAttribute

applicationContext

@Nullable
private cn.taketoday.context.ApplicationContext applicationContext

targetBeanName

@Nullable
private String targetBeanName

targetFilterLifecycle

private boolean targetFilterLifecycle

delegate

@Nullable
private volatile Filter delegate

delegateMonitor

private final Object delegateMonitor

构造器详细资料

DelegatingFilterProxy

public DelegatingFilterProxy()

Create a new DelegatingFilterProxy. For traditional use in web.xml.

另请参阅:

• setTargetBeanName(String)

DelegatingFilterProxy

public DelegatingFilterProxy(Filter delegate)

Create a new DelegatingFilterProxy with the given Filter delegate. Bypasses entirely the need for interacting with a Framework application context, specifying the target bean name, etc.

For use with instance-based registration of filters.

参数:

delegate - the Filter instance that this proxy will delegate to and manage the lifecycle for (must not be null).

另请参阅:

• doFilter(ServletRequest, ServletResponse, FilterChain)
• invokeDelegate(Filter, ServletRequest, ServletResponse, FilterChain)
• destroy()
• GenericFilterBean.setEnvironment(cn.taketoday.core.env.Environment)

DelegatingFilterProxy

public DelegatingFilterProxy(String targetBeanName)

Create a new DelegatingFilterProxy that will retrieve the named target bean from the Framework WebApplicationContext found in the ServletContext (either the 'root' application context or the context named by setContextAttribute(java.lang.String)).

For use with instance-based registration of filters.

The target bean must implement the standard Servlet Filter interface.

参数:

targetBeanName - name of the target filter bean to look up in the Framework application context (must not be null).

另请参阅:

• findApplicationContext()
• GenericFilterBean.setEnvironment(cn.taketoday.core.env.Environment)

DelegatingFilterProxy

public DelegatingFilterProxy(String targetBeanName,
 @Nullable
 cn.taketoday.context.ApplicationContext wac)

Create a new DelegatingFilterProxy that will retrieve the named target bean from the given Framework WebApplicationContext.

For use with instance-based registration of filters.

The target bean must implement the standard Servlet Filter interface.

The given WebApplicationContext may or may not be refreshed when passed in. If it has not, and if the context implements ConfigurableApplicationContext, a refresh() will be attempted before retrieving the named target bean.

This proxy's Environment will be inherited from the given WebApplicationContext.

参数:

targetBeanName - name of the target filter bean in the Framework application context (must not be null).

wac - the application context from which the target filter will be retrieved; if null, an application context will be looked up from ServletContext as a fallback.

另请参阅:

• findApplicationContext()
• GenericFilterBean.setEnvironment(cn.taketoday.core.env.Environment)

方法详细资料

setContextAttribute

public void setContextAttribute(@Nullable
 String contextAttribute)

Set the name of the ServletContext attribute which should be used to retrieve the WebApplicationContext from which to load the delegate Filter bean.

getContextAttribute

@Nullable
public String getContextAttribute()

Return the name of the ServletContext attribute which should be used to retrieve the WebApplicationContext from which to load the delegate Filter bean.

setTargetBeanName

public void setTargetBeanName(@Nullable
 String targetBeanName)

Set the name of the target bean in the Framework application context. The target bean must implement the standard Servlet Filter interface.

By default, the filter-name as specified for the DelegatingFilterProxy in web.xml will be used.

getTargetBeanName

@Nullable
protected String getTargetBeanName()

Return the name of the target bean in the Framework application context.

setTargetFilterLifecycle

public void setTargetFilterLifecycle(boolean targetFilterLifecycle)

Set whether to invoke the Filter.init and Filter.destroy lifecycle methods on the target bean.

Default is "false"; target beans usually rely on the Framework application context for managing their lifecycle. Setting this flag to "true" means that the servlet container will control the lifecycle of the target Filter, with this proxy delegating the corresponding calls.

isTargetFilterLifecycle

protected boolean isTargetFilterLifecycle()

Return whether to invoke the Filter.init and Filter.destroy lifecycle methods on the target bean.

initFilterBean

protected void initFilterBean()
                       throws ServletException

从类复制的说明: GenericFilterBean

Subclasses may override this to perform custom initialization. All bean properties of this filter will have been set before this method is invoked.

Note: This method will be called from standard filter initialization as well as filter bean initialization in a Framework application context. Filter name and ServletContext will be available in both cases.

This default implementation is empty.

覆盖:

initFilterBean 在类中 GenericFilterBean

抛出:

ServletException - if subclass initialization fails

另请参阅:

• GenericFilterBean.getFilterName()
• GenericFilterBean.getServletContext()

doFilter

public void doFilter(ServletRequest request,
 ServletResponse response,
 FilterChain filterChain)
              throws ServletException,
IOException

抛出:

ServletException

IOException

destroy

public void destroy()

从类复制的说明: GenericFilterBean

Subclasses may override this to perform custom filter shutdown.

Note: This method will be called from standard filter destruction as well as filter bean destruction in a Framework application context.

This default implementation is empty.

指定者:

destroy 在接口中 cn.taketoday.beans.factory.DisposableBean

指定者:

destroy 在接口中 Filter

覆盖:

destroy 在类中 GenericFilterBean

findApplicationContext

@Nullable
protected cn.taketoday.context.ApplicationContext findApplicationContext()

Return the WebApplicationContext passed in at construction time, if available. Otherwise, attempt to retrieve a WebApplicationContext from the ServletContext attribute with the configured name if set. Otherwise look up a WebApplicationContext under the well-known "root" application context attribute. The WebApplicationContext must have already been loaded and stored in the ServletContext before this filter gets initialized (or invoked).

Subclasses may override this method to provide a different WebApplicationContext retrieval strategy.

返回:

the WebApplicationContext for this proxy, or null if not found

另请参阅:

• DelegatingFilterProxy(String, ApplicationContext)
• getContextAttribute()
• WebApplicationContextUtils.getWebApplicationContext(jakarta.servlet.ServletContext)
• WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE

initDelegate

protected Filter initDelegate(cn.taketoday.context.ApplicationContext wac)
                       throws ServletException

Initialize the Filter delegate, defined as bean the given Framework application context.

The default implementation fetches the bean from the application context and calls the standard Filter.init method on it, passing in the FilterConfig of this Filter proxy.

参数:

wac - the root application context

返回:

the initialized delegate Filter

抛出:

ServletException - if thrown by the Filter

另请参阅:

• getTargetBeanName()
• isTargetFilterLifecycle()
• GenericFilterBean.getFilterConfig()
• Filter.init(jakarta.servlet.FilterConfig)

invokeDelegate

protected void invokeDelegate(Filter delegate,
 ServletRequest request,
 ServletResponse response,
 FilterChain filterChain)
                       throws ServletException,
IOException

Actually invoke the delegate Filter with the given request and response.

参数:

delegate - the delegate Filter

request - the current HTTP request

response - the current HTTP response

filterChain - the current FilterChain

抛出:

ServletException - if thrown by the Filter

IOException - if thrown by the Filter

destroyDelegate

protected void destroyDelegate(Filter delegate)

Destroy the Filter delegate. Default implementation simply calls Filter.destroy on it.

参数:

delegate - the Filter delegate (never null)

另请参阅:

• isTargetFilterLifecycle()
• Filter.destroy()