org.springframework.web.multipart.support
Class MultipartFilter

java.lang.Object
  extended by org.springframework.web.filter.GenericFilterBean
      extended by org.springframework.web.filter.OncePerRequestFilter
          extended by org.springframework.web.multipart.support.MultipartFilter
All Implemented Interfaces:
javax.servlet.Filter, BeanNameAware, DisposableBean, InitializingBean, ServletContextAware

public class MultipartFilter
extends OncePerRequestFilter

Servlet 2.3 Filter that resolves multipart requests via a MultipartResolver. in the root web application context.

Looks up the MultipartResolver in Spring's root web application context. Supports a "multipartResolverBeanName" filter init-param in web.xml; the default bean name is "filterMultipartResolver". Looks up the MultipartResolver on each request, to avoid initialization order issues (when using ContextLoaderServlet, the root application context will get initialized after this filter).

MultipartResolver lookup is customizable: Override this filter's lookupMultipartResolver method to use a custom MultipartResolver instance, for example if not using a Spring web application context. Note that the lookup method should not create a new MultipartResolver instance for each call but rather return a reference to a pre-built instance.

Note: This filter is an alternative to using DispatcherServlet's MultipartResolver support, for example for web applications with custom web views that do not use Spring's web MVC. It should not be combined with servlet-specific multipart resolution.

Since:
08.10.2003
Author:
Juergen Hoeller
See Also:
setMultipartResolverBeanName(java.lang.String), lookupMultipartResolver(javax.servlet.http.HttpServletRequest), MultipartResolver, DispatcherServlet

Field Summary
static java.lang.String DEFAULT_MULTIPART_RESOLVER_BEAN_NAME
           
 
Fields inherited from class org.springframework.web.filter.OncePerRequestFilter
ALREADY_FILTERED_SUFFIX
 
Fields inherited from class org.springframework.web.filter.GenericFilterBean
logger
 
Constructor Summary
MultipartFilter()
           
 
Method Summary
protected  void doFilterInternal(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, javax.servlet.FilterChain filterChain)
          Check for a multipart request via this filter's MultipartResolver, and wrap the original request with a MultipartHttpServletRequest if appropriate.
protected  java.lang.String getMultipartResolverBeanName()
          Return the bean name of the MultipartResolver to fetch from Spring's root application context.
protected  MultipartResolver lookupMultipartResolver()
          Look for a MultipartResolver bean in the root web application context.
protected  MultipartResolver lookupMultipartResolver(javax.servlet.http.HttpServletRequest request)
          Look up the MultipartResolver that this filter should use, taking the current HTTP request as argument.
 void setMultipartResolverBeanName(java.lang.String multipartResolverBeanName)
          Set the bean name of the MultipartResolver to fetch from Spring's root application context.
 
Methods inherited from class org.springframework.web.filter.OncePerRequestFilter
doFilter, getAlreadyFilteredAttributeName, shouldNotFilter
 
Methods inherited from class org.springframework.web.filter.GenericFilterBean
addRequiredProperty, afterPropertiesSet, destroy, getFilterConfig, getFilterName, getServletContext, init, initBeanWrapper, initFilterBean, setBeanName, setServletContext
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

DEFAULT_MULTIPART_RESOLVER_BEAN_NAME

public static final java.lang.String DEFAULT_MULTIPART_RESOLVER_BEAN_NAME
See Also:
Constant Field Values
Constructor Detail

MultipartFilter

public MultipartFilter()
Method Detail

setMultipartResolverBeanName

public void setMultipartResolverBeanName(java.lang.String multipartResolverBeanName)
Set the bean name of the MultipartResolver to fetch from Spring's root application context. Default is "filterMultipartResolver".


getMultipartResolverBeanName

protected java.lang.String getMultipartResolverBeanName()
Return the bean name of the MultipartResolver to fetch from Spring's root application context.


doFilterInternal

protected void doFilterInternal(javax.servlet.http.HttpServletRequest request,
                                javax.servlet.http.HttpServletResponse response,
                                javax.servlet.FilterChain filterChain)
                         throws javax.servlet.ServletException,
                                java.io.IOException
Check for a multipart request via this filter's MultipartResolver, and wrap the original request with a MultipartHttpServletRequest if appropriate.

All later elements in the filter chain, most importantly servlets, benefit from proper parameter extraction in the multipart case, and are able to cast to MultipartHttpServletRequest if they need to.

Specified by:
doFilterInternal in class OncePerRequestFilter
Throws:
javax.servlet.ServletException
java.io.IOException

lookupMultipartResolver

protected MultipartResolver lookupMultipartResolver(javax.servlet.http.HttpServletRequest request)
Look up the MultipartResolver that this filter should use, taking the current HTTP request as argument.

Default implementation delegates to the lookupMultipartResolver without arguments.

Returns:
the MultipartResolver to use
See Also:
lookupMultipartResolver()

lookupMultipartResolver

protected MultipartResolver lookupMultipartResolver()
Look for a MultipartResolver bean in the root web application context. Supports a "multipartResolverBeanName" filter init param; the default bean name is "filterMultipartResolver".

This can be overridden to use a custom MultipartResolver instance, for example if not using a Spring web application context.

Returns:
the MultipartResolver instance, or null if none found