你有一个无尽的循环。在你的代码里，你需要

tokenizer.nextToken()

将stringtokenizer从行中向前推进一个单词。否则，Map操作将永远不会取得进展。
所以你需要这样的东西：

public static class Map extends Mapper<LongWritable, Text, Text, IntWritable> {
        private final static IntWritable one = new IntWritable(1);
        private Text sumText = new Text("Sum: ");
    public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
        String line = value.toString();
        StringTokenizer tokenizer = new StringTokenizer(line);
        while (tokenizer.hasMoreTokens()) {
            tokenizer.nextToken(); //go to next word
            context.write(sumText, one);
        }
    }
}

但是，没有循环还有更好的解决方案。你可以用ẗ他 countTokens() stringtokenizer的方法：

public static class Map extends Mapper<LongWritable, Text, Text, IntWritable> {
    public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
        String line = value.toString();
        StringTokenizer tokenizer = new StringTokenizer(line);
        context.write(new Text("Sum: "), new IntWritable(tokenizer.countTokens()));
    }
}