我有一个mapreduce程序,该程序的reduce方法输出Text
作为键,并输出FloatArrayWritable
作为值。但是,这些值将输出数组地址,而不是toString()
方法的值。
我得到的输出是:IYE marketDataPackage.MarketData@69204998IYE marketDataPackage.MarketData@69204998
输出应为:IYE 38.89, 38.50, etc.
有人可以告知我代码中的错误吗?谢谢。
public static class Map extends Mapper<LongWritable, Text, Text, MarketData> {
private Text symbol = new Text();
public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
String line = value.toString();
StringTokenizer tokenizer = new StringTokenizer(line);
while (tokenizer.hasMoreTokens()) {
StringTokenizer tokenizer2 = new StringTokenizer(tokenizer.nextToken().toString(), ",");
symbol.set(tokenizer2.nextToken());
context.write(symbol, new MarketData(tokenizer2.nextToken(), Float.parseFloat(tokenizer2.nextToken())));
}
}
}
public static class Reduce extends Reducer<Text, FloatWritable, Text, FloatArrayWritable> {
public void reduce(Text key, Iterable<MarketData> values, Context context) throws IOException, InterruptedException, ParseException {
Calendar today = Calendar.getInstance();
today.add(Calendar.DAY_OF_MONTH, -45);
Calendar testDate = Calendar.getInstance();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy/m/d");
List<FloatWritable> prices = new ArrayList<FloatWritable>();
for (MarketData m : values) {
testDate.setTime(sdf.parse(m.getTradeDate()));
if (testDate.after(today)) {
prices.add(new FloatWritable(m.getPrice()));
}
}
context.write(key, new FloatArrayWritable(prices.toArray(new FloatWritable[prices.size()])));
}
}
public static void main(String[] args) {
Configuration conf = new Configuration();
Job job = new Job(conf, "Security_Closing_Prices");
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(MarketData.class);
job.setMapperClass(Map.class);
job.setReducerClass(Reduce.class);
job.setInputFormatClass(TextInputFormat.class);
job.setOutputFormatClass(TextOutputFormat.class);
FileInputFormat.addInputPath(job, new Path(args[0]));
FileOutputFormat.setOutputPath(job, new Path(args[1]));
job.waitForCompletion(true);
}
FloatArrayWritable类:
public class FloatArrayWritable extends ArrayWritable {
public FloatArrayWritable() {
super(FloatWritable.class);
}
public FloatArrayWritable(FloatWritable[] values) {
super(FloatWritable.class, values);
}
@Override
public FloatWritable[] get() {
return (FloatWritable[]) super.get();
}
@Override
public String toString() {
FloatWritable[] values = get();
String prices = "";
for (FloatWritable f : values) {
prices = prices + f.toString() + ", ";
}
if (prices != null && !prices.isEmpty()) {
prices = prices.substring(0, prices.length() - 2);
}
return prices;
}
}
最佳答案
MarketData
类应覆盖toString()
。您没有为该类提供代码,但是我怀疑没有。