Question

让我们看看我们有什么。第一个文件[接口类]：

list arrayList
list linkedList

第二档[Class1金额]：

arrayList 120
linkedList 4

我想按键[Class]加入这两个文件，并按每个接口计算：

list arraylist 120
list linkedlist 4

代码：

public class Main
{
public static void main( String[] args )
{
String docPath = args[ 0 ];
String wcPath = args[ 1 ];
String doc2Path = args[ 2 ];

Properties properties = new Properties();
AppProps.setApplicationJarClass( properties, Main.class );
AppProps.setApplicationName( properties, "Part 1" );
AppProps.addApplicationTag( properties, "lets:do:it" );
AppProps.addApplicationTag( properties, "technology:Cascading" );
FlowConnector flowConnector = new Hadoop2MR1FlowConnector( properties );

// create source and sink taps
Tap wcTap = new Hfs(new TextDelimited(true, ","), wcPath);


    Fields classInterfaceFiles = new Fields("interface", "class");
    Tap classInterfaceTap = new Hfs(new TextDelimited(classInterfaceFiles, true, ","), docPath);

    Fields classAmountFields = new Fields("class1", "amount");
    Tap classAmountFileTap = new Hfs(new TextDelimited(classAmountFields, true, ","), doc2Path);

    Tap outTap = new MultiSinkTap(); // just saying, create your own tap
    Pipe classInterfaceFilePipe = new Pipe("classInterfaceFilePipe");

    Pipe classIAmountFilePipe = new Pipe("classIAmountFilePipe");

    Fields groupFields = new Fields("class");
    Fields groupFields1 = new Fields("class1"); // fields used as joining keys
    Pipe outPipe = new CoGroup(classInterfaceFilePipe, groupFields, classIAmountFilePipe, groupFields1, new InnerJoin());


 // build flow definition
    FlowDef flowDef = FlowDef.flowDef().setName("myFlow")
            .addSource(classInterfaceFilePipe, classInterfaceTap)
            .addSource(classIAmountFilePipe, classAmountFileTap)
            .addTailSink(outPipe, wcTap);
         //   .addTailSink( outPipe, wcTap );


// write a DOT file and run the flow
Flow wcFlow = flowConnector.connect( flowDef );
wcFlow.writeDOT( "dot/wc.dot" );
wcFlow.complete();
}

}

[这是更大任务的一步]

Answer 1

这种情况正在发生，因为你在两个连接在一起的管道中有相同的字段，即“类”。可能你可以将它们重命名为“class_interface”和“class_amount”。您还必须在CoGroup管道中使用的groupField中进行更改。

无法通过Cascading将一个密钥加入两个文件

1 个答案: