运行一个简单的本地模式级联程序

Question

我正在努力将这个简单的级联程序添加到运行。由于某种原因，它什么都不做。至少我希望它能打印记录。任何帮助将不胜感激。

package com.myLearning.cascading;

import cascading.flow.Flow;
import cascading.flow.FlowDef;
import cascading.flow.local.LocalFlowConnector;
import cascading.operation.Debug;
import cascading.operation.expression.ExpressionFilter;
import cascading.pipe.Each;
import cascading.pipe.Pipe;
import cascading.scheme.Scheme;
import cascading.scheme.local.TextDelimited;
import cascading.tap.SinkMode;
import cascading.tap.Tap;
import cascading.tap.local.FileTap;
import cascading.tuple.Fields;

public class operations_example 
{
    public static void main(String[] args) 
    {
    Scheme sourceScheme = new TextDelimited(new Fields("username", "age"), true, ",");
    String sourcePath = "C:/Users/Desktop/cascading/data/names.txt";
    Tap sourceTap = new FileTap(sourceScheme, sourcePath);

    Scheme targetScheme = new TextDelimited(new Fields("username", "age"), true, ",");
    String targetPath = "C:/Users/Desktop/cascading/data/output2.txt";
    Tap targetTap = new FileTap(targetScheme, targetPath, SinkMode.REPLACE);

    Pipe dataPipe = new Pipe("data");
    dataPipe = new Each(dataPipe, new Debug());
    ExpressionFilter filter = new ExpressionFilter("age >= 30", Integer.TYPE);

    dataPipe = new Each( dataPipe,new Fields("username","age"), filter);

    FlowDef flowdef = FlowDef.flowDef().
            addSource(dataPipe, sourceTap).
            addTailSink(dataPipe, targetTap);

    Flow flow = new LocalFlowConnector().connect(flowdef);
    flow.stop();    
    }
}

Answer 1

你没有执行流程。

流创建后，调用 complete()（阻塞）或 start() 来执行它。调用stop()是不去执行流程。

http://docs.cascading.org/impatient/impatient1.html http://docs.cascading.org/cascading/1.2/javadoc/cascading/flow/Flow.html#complete()

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