Class TryPathsHandler

java.lang.Object
org.eclipse.jetty.util.component.AbstractLifeCycle
org.eclipse.jetty.util.component.ContainerLifeCycle
org.eclipse.jetty.server.Handler.Abstract
org.eclipse.jetty.server.Handler.AbstractContainer
org.eclipse.jetty.server.Handler.Wrapper
org.eclipse.jetty.server.handler.TryPathsHandler
All Implemented Interfaces:
Handler, Handler.Container, Handler.Singleton, Request.Handler, Container, Destroyable, Dumpable, Dumpable.DumpableContainer, LifeCycle, Invocable
public class TryPathsHandler extends Handler.Wrapper

Inspired by nginx's try_files functionality.

This handler can be configured with a list of rewrite URI paths. The special token $path represents the current request pathInContext (the portion after the context path).

Typical example of how this handler can be configured is the following:

TryPathsHandler tryPathsHandler = new TryPathsHandler();
tryPathsHandler.setPaths("/maintenance.html", "$path", "/index.php?p=$path");

PathMappingsHandler pathMappingsHandler = new PathMappingsHandler();
tryPathsHandler.setHandler(pathMappingsHandler);

pathMappingsHandler.addMapping(new ServletPathSpec("*.php"), new PHPHandler());
pathMappingsHandler.addMapping(new ServletPathSpec("/"), new ResourceHandler());

For a request such as /context/path/to/resource.ext:

  • This handler rewrites the request pathInContext to /maintenance.html and forwards the request to the next handler, where it matches the / mapping, hitting the ResourceHandler that serves the file if it exists.
  • Otherwise, this handler rewrites the request pathInContext to /path/to/resource.ext and forwards the request to the next handler, where it matches the / mapping, hitting the ResourceHandler that serves the file if it exists.
  • Otherwise, this handler rewrites the request pathInContext to /index.php?p=/path/to/resource.ext and forwards the request to the next handler, where it matches the *.php mapping, hitting the PHPHandler.

The original path and query may be stored as request attributes, under the names specified by setOriginalPathAttribute(String) and setOriginalQueryAttribute(String).

  • Constructor Details

    • TryPathsHandler

      public TryPathsHandler()

    • TryPathsHandler

      public TryPathsHandler(Handler handler)

  • Method Details

    • getOriginalPathAttribute

      public String getOriginalPathAttribute()
      Get the attribute name of the original request path.
      Returns:
      the attribute name of the original request path

    • setOriginalPathAttribute

      public void setOriginalPathAttribute(String originalPathAttribute)

      Sets the request attribute name to use to retrieve the original request path.

      Parameters:
      originalPathAttribute - the attribute name of the original request path

    • getOriginalQueryAttribute

      public String getOriginalQueryAttribute()
      Get the attribute name of the original request query.
      Returns:
      the attribute name of the original request query

    • setOriginalQueryAttribute

      public void setOriginalQueryAttribute(String originalQueryAttribute)

      Sets the request attribute name to use to retrieve the original request query.

      Parameters:
      originalQueryAttribute - the attribute name of the original request query

    • getPaths

      public List<String> getPaths()
      Returns:
      the rewrite URI paths

    • setPaths

      public void setPaths(List<String> paths)

      Sets a list of rewrite URI paths.

      The special token $path represents the current request pathInContext (the portion after the context path).

      Parameters:
      paths - the rewrite URI paths

    • handle

      public boolean handle(Request request, Response response, Callback callback) throws Exception
      Description copied from interface: Request.Handler

      Invoked to handle the passed HTTP request and response.

      The request is accepted by returning true, then handling must be concluded by completing the passed callback. The handling may be asynchronous, i.e. this method may return true and complete the given callback later, possibly from a different thread. If this method returns false, then the callback must not be invoked and any mutation on the response reversed.

      Exceptions thrown by this method may be subsequently handled by an error Request.Handler, if present, otherwise a default HTTP 500 error is generated and the callback completed while writing the error response.

      The simplest implementation is:

      public boolean handle(Request request, Response response, Callback callback)
{
    callback.succeeded();
    return true;
}

      A HelloWorld implementation is:

      public boolean handle(Request request, Response response, Callback callback)
{
    response.write(true, ByteBuffer.wrap("Hello World\n".getBytes(StandardCharsets.UTF_8)), callback);
    return true;
}
      Specified by:
      handle in interface Request.Handler
      Overrides:
      handle in class Handler.Wrapper
      Parameters:
      request - the HTTP request to handle
      response - the HTTP response to handle
      callback - the callback to complete when the handling is complete
      Returns:
      True if and only if the request will be handled, a response generated and the callback eventually called. This may occur within the scope of the call to this method, or asynchronously some time later. If false is returned, then this method must not generate a response, nor complete the callback.
      Throws:
      Exception - if there is a failure during the handling. Catchers cannot assume that the callback will be called and thus should attempt to complete the request as if a false had been returned.
      See Also: