simple

Class Grep

  • java.lang.Object
    • simple.Grep


  • public class Grep
    extends java.lang.Object
    Sample continuous (streaming) grep topology application. This Java application builds a simple topology that watches a directory for files, reads each file and output lines that contain the search term. Thus as each file is added to the directory, the application will read it and output matching lines.
    The application implements the typical pattern of code that declares a topology followed by submission of the topology to a Streams context com.ibm.streamsx.topology.context.StreamsContext.
    This demonstrates the a continuous application and use of utility classes that produce streams.


    This may be executed from the samples/java/functional directory as:

    • java -cp functionalsamples.jar:../../../com.ibm.streamsx.topology/lib/com.ibm.streamsx.topology.jar:$STREAMS_INSTALL/lib/com.ibm.streams.operator.samples.jar simple.Grep CONTEXT_TYPE $HOME/books Elizabeth - Run directly from the command line.
    • CONTEXT_TYPE is one of:
      • DISTRIBUTED - Run as an IBM Streams distributed application.
      • STANDALONE - Run as an IBM Streams standalone application.
      • EMBEDDED - Run embedded within this JVM.
      • BUNDLE - Create an IBM Streams application bundle.
      • TOOLKIT - Create an IBM Streams application toolkit.
    • An application execution within your IDE once you set the class path to include the correct jars.

    • Constructor Summary

      Constructors 
      Constructor and Description
      Grep() 
    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method and Description
      static void main(java.lang.String[] args)
      Sample continuous (streaming) grep topology application.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • Grep

        public Grep()
    • Method Detail

      • main

        public static void main(java.lang.String[] args)
                         throws java.lang.Exception
        Sample continuous (streaming) grep topology application. This Java application builds a simple topology that watches a directory for files, reads each file and output lines that contain the search term. Thus as each file is added to the directory, the application will read it and output matching lines.
        The application implements the typical pattern of code that declares a topology followed by submission of the topology to a Streams context com.ibm.streamsx.topology.context.StreamsContext.

        Three arguments are required:

        • contextType - The type of the context to execute the topology in, e.g. EMBEDDED or STANDALONE.
        • directory - Directory to watch for files.
        • term - Search term, if any line in a file contains term then it will be printed.
        For example (classpath omitted for brevity):
        java simple.Grep EMBEDDED $HOME/books Elizabeth
        Throws:
        java.lang.Exception
streamsx.topology @ IBMStreams GitHub