The document contains Java code using the Cascading framework, designed to process data related to M&M candy attributes such as color, width, and weight. It defines multiple classes to handle data parsing, aggregation (by color and total), and flow setup for reading from and writing to files. The code includes the main classes for executing data flows, custom aggregators, and data handling structures for computing averages.

1. package org.ajug;
import cascading.cascade.Cascade;
import cascading.cascade.CascadeConnector;
import cascading.flow.Flow;
import cascading.flow.FlowConnector;
import cascading.pipe.Each;
import cascading.pipe.Every;
import cascading.pipe.GroupBy;
import cascading.pipe.Pipe;
import cascading.scheme.TextDelimited;
import cascading.scheme.TextLine;
import cascading.tap.Hfs;
import cascading.tap.SinkMode;
import cascading.tap.Tap;
import cascading.tuple.Fields;
import java.util.Properties;
public class Main {
public static void main(String[] args) {
Properties properties = new Properties();
FlowConnector.setApplicationJarClass(properties, Main.class);
properties.put("mapred.reduce.tasks", 5);
Pipe mainPipe = new Each("M&M", new Fields("line"), new Parser());
mainPipe = new GroupBy(mainPipe, new Fields("COLOR"));
mainPipe = new Every(mainPipe, Fields.ALL, new ColorAggregator(new
ColorData()));
Tap sourceTap = new Hfs(new TextLine(), args[0]);
TextDelimited scheme = new TextDelimited(new Fields("COLOR",
"AVG_WIDTH", "AVG_WEIGHT"), ",", """);
scheme.setNumSinkParts(1); // make sure we only get one file
Tap sinkTap = new Hfs(scheme, args[1], SinkMode.REPLACE);
FlowConnector flowConnector = new FlowConnector(properties);
CascadeConnector cascadeConnector = new CascadeConnector();
Flow flow = flowConnector.connect(sourceTap, sinkTap, mainPipe);
Cascade cascade = cascadeConnector.connect(flow);
cascade.complete(); // Finally run everything
}
}
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package org.ajug;
import cascading.cascade.Cascade;
import cascading.cascade.CascadeConnector;
import cascading.flow.Flow;
import cascading.flow.FlowConnector;
import cascading.pipe.*;
import cascading.scheme.TextDelimited;

2. import cascading.scheme.TextLine;
import cascading.tap.Hfs;
import cascading.tap.SinkMode;
import cascading.tap.Tap;
import cascading.tuple.Fields;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
public class MultiOutputMain {
public static void main(String[] args) {
Properties properties = new Properties();
FlowConnector.setApplicationJarClass(properties, Main.class);
properties.put("mapred.reduce.tasks", 5);
Pipe sourcePipe = new Each("M&M", new Fields("line"), new Parser());
Pipe totalPipe = new GroupBy("Total", sourcePipe, new Fields("ONE"));
totalPipe = new Every(totalPipe, Fields.ALL, new TotalAggregator(new
TotalData()));
Pipe mainPipe = new GroupBy("Color", sourcePipe, new Fields("COLOR"));
mainPipe = new Every(mainPipe, Fields.ALL, new ColorAggregator(new
ColorData()));
Tap sourceTap = new Hfs(new TextLine(), args[0]);
TextDelimited scheme = new TextDelimited(new Fields("COLOR",
"AVG_WIDTH", "AVG_WEIGHT"), ",", """);
scheme.setNumSinkParts(1); // make sure we only get one file
Tap colorTap = new Hfs(scheme, args[1] + "/color", SinkMode.REPLACE);
TextDelimited totalScheme = new TextDelimited(new
Fields("FINAL_WIDTH", "FINAL_WEIGHT"), ",", """);
totalScheme.setNumSinkParts(1); // make sure we only get one file
Tap totalTap = new Hfs(totalScheme, args[1] + "/total",
SinkMode.REPLACE);
FlowConnector flowConnector = new FlowConnector(properties);
CascadeConnector cascadeConnector = new CascadeConnector();
Map<String, Tap> outputs = new HashMap<String, Tap>();
outputs.put(totalPipe.getName(), totalTap);
outputs.put(mainPipe.getName(), colorTap);
Flow flow = flowConnector.connect(sourceTap, outputs, totalPipe,
mainPipe);
Cascade cascade = cascadeConnector.connect(flow);
cascade.complete(); // Finally run everything
}
}
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package org.ajug;

3. import cascading.flow.FlowProcess;
import cascading.operation.Function;
import cascading.operation.FunctionCall;
import cascading.tuple.Fields;
import cascading.tuple.Tuple;
import java.io.Serializable;
public class Parser extends cascading.operation.BaseOperation implements
Serializable, Function {
public Parser() {
super(new Fields("ONE","COLOR", "WIDTH", "WEIGHT")); // should be
constants file ;)
}
public void operate(FlowProcess a_flow, FunctionCall a_call) {
String sourceData = a_call.getArguments().getString(0);
sourceData = sourceData.trim();
if (sourceData == null || sourceData.length() == 0) {
return; // blank line read from the source file, so ignore
it
}
String values[] = sourceData.split(",");
Tuple output = new Tuple();
output.add("1");
output.add(values[0]);
output.add(values[1]);
output.add(values[2]);
a_call.getOutputCollector().add(output);
}
}
==============================================
package org.ajug;
import cascading.tuple.Tuple;
import java.io.Serializable;
public class ColorData implements Serializable {
private long m_num = 0;
private double m_width = 0;
private double m_weight = 0;
public void reset(){
m_num = 0;
m_width = 0;
m_weight = 0;
}

4. public void addData(double a_weight, double a_width){
m_weight += a_weight;
m_width+=a_width;
m_num++;
}
public Tuple getTuple() {
if (m_num == 0) return null;
Tuple rtnValue = new Tuple();
rtnValue.add(m_width/m_num);
rtnValue.add(m_weight/m_num);
return rtnValue;
}
}
===============================================
package org.ajug;
import cascading.tuple.Tuple;
import java.io.Serializable;
public class TotalData implements Serializable {
private long m_num = 0;
private double m_width = 0;
private double m_weight = 0;
public void reset(){
m_num = 0;
m_width = 0;
m_weight = 0;
}
public void addData(double a_weight, double a_width){
m_weight += a_weight;
m_width+=a_width;
m_num++;
}
public Tuple getTuple() {
if (m_num == 0) return null;
Tuple rtnValue = new Tuple();
rtnValue.add(m_width/m_num);
rtnValue.add(m_weight/m_num);
return rtnValue;
}
}
==================================================
package org.ajug;

5. import cascading.flow.FlowProcess;
import cascading.operation.Aggregator;
import cascading.operation.AggregatorCall;
import cascading.operation.BaseOperation;
import cascading.tuple.Fields;
import cascading.tuple.Tuple;
import cascading.tuple.TupleEntry;
import org.apache.log4j.Logger;
public class TotalAggregator extends BaseOperation<TotalData>
implements Aggregator<TotalData> {
static Logger m_logger =
Logger.getLogger(TotalAggregator.class.getName());
private TotalData m_row;
public TotalAggregator(TotalData a_row) {
super(new Fields("FINAL_WIDTH", "FINAL_WEIGHT"));
m_row = a_row;
}
public void start(FlowProcess flowProcess,
AggregatorCall<TotalData> aggregatorCall) {
// set the context object
m_row.reset();
aggregatorCall.setContext(m_row);
}
public void complete(FlowProcess flowProcess,
AggregatorCall<TotalData> aggregatorCall) {
TotalData context = aggregatorCall.getContext();
Tuple results = context.getTuple();
if (results == null) return; // Nothing there to report
aggregatorCall.getOutputCollector().add(results);
}
public void aggregate(FlowProcess flowProcess,
AggregatorCall<TotalData> aggregatorCall) {
TupleEntry arguments = aggregatorCall.getArguments();
TotalData context = aggregatorCall.getContext();
double weight = arguments.getDouble("WEIGHT");
double width = arguments.getDouble("WIDTH");
context.addData(weight, width);
}
}
=========================================
package org.ajug;
import cascading.flow.FlowProcess;
import cascading.operation.Aggregator;
import cascading.operation.AggregatorCall;

6. import cascading.operation.BaseOperation;
import cascading.tuple.Fields;
import cascading.tuple.Tuple;
import cascading.tuple.TupleEntry;
import org.apache.log4j.Logger;
public class ColorAggregator extends BaseOperation<ColorData>
implements Aggregator<ColorData> {
static Logger m_logger =
Logger.getLogger(ColorAggregator.class.getName());
private ColorData m_row;
public ColorAggregator(ColorData a_row) {
super(new Fields("AVG_WIDTH", "AVG_WEIGHT"));
m_row = a_row;
}
public void start(FlowProcess flowProcess,
AggregatorCall<ColorData> aggregatorCall) {
// set the context object
m_row.reset();
aggregatorCall.setContext(m_row);
}
public void complete(FlowProcess flowProcess,
AggregatorCall<ColorData> aggregatorCall) {
ColorData context = aggregatorCall.getContext();
Tuple results = context.getTuple();
if (results == null) return; // Nothing there to report
aggregatorCall.getOutputCollector().add(results);
}
public void aggregate(FlowProcess flowProcess,
AggregatorCall<ColorData> aggregatorCall) {
TupleEntry arguments = aggregatorCall.getArguments();
ColorData context = aggregatorCall.getContext();
double weight = arguments.getDouble("WEIGHT");
double width = arguments.getDouble("WIDTH");
context.addData(weight, width);
}
}