Package io.grpc.servlet.jakarta

Class ServletAdapter

java.lang.Object
io.grpc.servlet.jakarta.ServletAdapter
@ExperimentalApi("https://github.com/grpc/grpc-java/issues/5066") public final class ServletAdapter extends Object
An adapter that transforms HttpServletRequest into gRPC request and lets a gRPC server process it, and transforms the gRPC response into HttpServletResponse. An adapter can be instantiated by ServletServerBuilder.buildServletAdapter().

In a servlet, calling doPost(HttpServletRequest, HttpServletResponse) inside HttpServlet.doPost(HttpServletRequest, HttpServletResponse) makes the servlet backed by the gRPC server associated with the adapter. The servlet must support Asynchronous Processing and must be deployed to a container that supports servlet 4.0 and enables HTTP/2.

The API is experimental. The authors would like to know more about the real usecases. Users are welcome to provide feedback by commenting on the tracking issue.

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static interface 
    ServletAdapter.AdapterConstructor<T>
     

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    destroy()
    Call this method when the adapter is no longer needed.
    void
    doGet(jakarta.servlet.http.HttpServletRequest req, jakarta.servlet.http.HttpServletResponse resp)
    Call this method inside HttpServlet.doGet(HttpServletRequest, HttpServletResponse) to serve gRPC GET request.
    void
    doPost(jakarta.servlet.http.HttpServletRequest req, jakarta.servlet.http.HttpServletResponse resp)
    Call this method inside HttpServlet.doPost(HttpServletRequest, HttpServletResponse) to serve gRPC POST request.
    static boolean
    isGrpc(jakarta.servlet.http.HttpServletRequest request)
    Checks whether an incoming HttpServletRequest may come from a gRPC client.
    <T> T
    otherAdapter(ServletAdapter.AdapterConstructor<T> constructor)
     

    Methods inherited from class java.lang.Object

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

  • Method Details

    • otherAdapter

      @ExperimentalApi("deephaven only, not submitted upstream") public <T> T otherAdapter(ServletAdapter.AdapterConstructor<T> constructor)

    • doGet

      public void doGet(jakarta.servlet.http.HttpServletRequest req, jakarta.servlet.http.HttpServletResponse resp) throws IOException
      Call this method inside HttpServlet.doGet(HttpServletRequest, HttpServletResponse) to serve gRPC GET request.

      This method is currently not implemented.

      Note that in rare case gRPC client sends GET requests.

      Do not modify req and resp before or after calling this method. However, calling resp.setBufferSize() before invocation is allowed.

      Throws:
      IOException

    • doPost

      public void doPost(jakarta.servlet.http.HttpServletRequest req, jakarta.servlet.http.HttpServletResponse resp) throws IOException
      Call this method inside HttpServlet.doPost(HttpServletRequest, HttpServletResponse) to serve gRPC POST request.

      Do not modify req and resp before or after calling this method. However, calling resp.setBufferSize() before invocation is allowed.

      Throws:
      IOException

    • destroy

      public void destroy()
      Call this method when the adapter is no longer needed. The gRPC server will be terminated.

    • isGrpc

      public static boolean isGrpc(jakarta.servlet.http.HttpServletRequest request)
      Checks whether an incoming HttpServletRequest may come from a gRPC client.
      Returns:
      true if the request comes from a gRPC client