@InterfaceAudience.Private public abstract class FileSystemReleaseFilter extends Object implements javax.servlet.Filter
FileSystemReleaseFilter releases back to the
 FileSystemAccess service a FileSystem instance.
 This filter is useful in situations where a servlet request is streaming out HDFS data and the corresponding filesystem instance have to be closed after the streaming completes.
| Constructor and Description | 
|---|
| FileSystemReleaseFilter() | 
| Modifier and Type | Method and Description | 
|---|---|
| void | destroy()Destroys the filter. | 
| void | doFilter(javax.servlet.ServletRequest servletRequest,
        javax.servlet.ServletResponse servletResponse,
        javax.servlet.FilterChain filterChain)It delegates the incoming request to the  FilterChain, and
 at its completion (in a finally block) releases the filesystem instance
 back to theFileSystemAccessservice. | 
| protected abstract FileSystemAccess | getFileSystemAccess()Abstract method to be implemetned by concrete implementations of the
 filter that return the  FileSystemAccessservice to which the filesystem
 will be returned to. | 
| void | init(javax.servlet.FilterConfig filterConfig)Initializes the filter. | 
| static void | setFileSystem(org.apache.hadoop.fs.FileSystem fs)Static method that sets the  FileSystemto release back to
 theFileSystemAccessservice on servlet request completion. | 
public void init(javax.servlet.FilterConfig filterConfig)
          throws javax.servlet.ServletException
This implementation is a NOP.
init in interface javax.servlet.FilterfilterConfig - filter configuration.javax.servlet.ServletException - thrown if the filter could not be initialized.public void doFilter(javax.servlet.ServletRequest servletRequest,
                     javax.servlet.ServletResponse servletResponse,
                     javax.servlet.FilterChain filterChain)
              throws IOException,
                     javax.servlet.ServletException
FilterChain, and
 at its completion (in a finally block) releases the filesystem instance
 back to the FileSystemAccess service.doFilter in interface javax.servlet.FilterservletRequest - servlet request.servletResponse - servlet response.filterChain - filter chain.IOException - thrown if an IO error occurs.javax.servlet.ServletException - thrown if a servlet error occurs.public void destroy()
This implementation is a NOP.
destroy in interface javax.servlet.Filterpublic static void setFileSystem(org.apache.hadoop.fs.FileSystem fs)
FileSystem to release back to
 the FileSystemAccess service on servlet request completion.fs - fileystem instance.protected abstract FileSystemAccess getFileSystemAccess()
FileSystemAccess service to which the filesystem
 will be returned to.Copyright © 2008–2023 Apache Software Foundation. All rights reserved.