我对cascading/hadoop不太熟悉，正在尝试以本地模式（即在内存中）运行一个简单的示例。该示例仅复制一个文件：

import java.util.Properties;
    import cascading.flow.Flow;
    import cascading.flow.FlowConnector;
    import cascading.flow.FlowDef;
    import cascading.flow.local.LocalFlowConnector;
    import cascading.pipe.Pipe;
    import cascading.property.AppProps;
    import cascading.scheme.hadoop.TextLine;
    import cascading.tap.Tap;
    import cascading.tap.hadoop.Hfs;
    public class CascadingTest {
            public static void main(String[] args) {
                Properties properties = new Properties();
                AppProps.setApplicationJarClass( properties, CascadingTest.class );
                FlowConnector flowConnector = new LocalFlowConnector();
                // create the source tap
                Tap inTap = new Hfs( new TextLine(), "D:\\git_workspace\\Impatient\\part1\\data\\rain.txt" );
            // create the sink tap
            Tap outTap = new Hfs( new TextLine(), "D:\\git_workspace\\Impatient\\part1\\data\\out.txt" );
            // specify a pipe to connect the taps
            Pipe copyPipe = new Pipe( "copy" );
            // connect the taps, pipes, etc., into a flow
            FlowDef flowDef = FlowDef.flowDef()
                .addSource( copyPipe, inTap )
                .addTailSink( copyPipe, outTap );
                // run the flow
            Flow flow = flowConnector.connect( flowDef );
            flow.complete();
        }
    }

下面是我得到的错误：

09-25-12 11:30:38,114 INFO  - AppProps                     - using app.id: 9C82C76AC667FDAA2F6969A0DF3949C6
Exception in thread "main" cascading.flow.planner.PlannerException: could not build flow from assembly: [java.util.Properties cannot be cast to org.apache.hadoop.mapred.JobConf]
    at cascading.flow.planner.FlowPlanner.handleExceptionDuringPlanning(FlowPlanner.java:515)
    at cascading.flow.local.planner.LocalPlanner.buildFlow(LocalPlanner.java:84)
    at cascading.flow.FlowConnector.connect(FlowConnector.java:454)
    at com.x.y.CascadingTest.main(CascadingTest.java:37)
Caused by: java.lang.ClassCastException: java.util.Properties cannot be cast to org.apache.hadoop.mapred.JobConf
    at cascading.tap.hadoop.Hfs.sourceConfInit(Hfs.java:78)
    at cascading.flow.local.LocalFlowStep.initTaps(LocalFlowStep.java:77)
    at cascading.flow.local.LocalFlowStep.getInitializedConfig(LocalFlowStep.java:56)
    at cascading.flow.local.LocalFlowStep.createFlowStepJob(LocalFlowStep.java:135)
    at cascading.flow.local.LocalFlowStep.createFlowStepJob(LocalFlowStep.java:38)
    at cascading.flow.planner.BaseFlowStep.getFlowStepJob(BaseFlowStep.java:588)
    at cascading.flow.BaseFlow.initializeNewJobsMap(BaseFlow.java:1162)
    at cascading.flow.BaseFlow.initialize(BaseFlow.java:184)
    at cascading.flow.local.planner.LocalPlanner.buildFlow(LocalPlanner.java:78)
    ... 2 more