如何在 Hadoop-.20 api 中指定 KeyValueTextInputFormat 分隔符?

2022-01-13 00:00:00 hadoop mapreduce java

在新 API (apache.hadoop.mapreduce.KeyValueTextInputFormat) 中，如何指定制表符(默认)以外的分隔符(分隔符)来分隔键和值.

In new API (apache.hadoop.mapreduce.KeyValueTextInputFormat) , how to specify separator (delimiter) other than tab(which is default) to separate key and Value.

示例输入:

one,first line
two,second line

需要输出:

Key : one
Value : first line
Key : two
Value : second line

我将 KeyValueTextInputFormat 指定为:

I am specifying KeyValueTextInputFormat as :

    Job job = new Job(conf, "Sample");

    job.setInputFormatClass(KeyValueTextInputFormat.class);
    KeyValueTextInputFormat.addInputPath(job, new Path("/home/input.txt"));

这对于作为分隔符的制表符来说效果很好.

This is working fine for tab as a separator.

推荐答案

在较新的 API 中，您应该使用 mapreduce.input.keyvaluelinerecordreader.key.value.separator 配置属性.

In the newer API you should use mapreduce.input.keyvaluelinerecordreader.key.value.separator configuration property.

这是一个例子:

Configuration conf = new Configuration();
conf.set("mapreduce.input.keyvaluelinerecordreader.key.value.separator", ",");

Job job = new Job(conf);
job.setInputFormatClass(KeyValueTextInputFormat.class);
// next job set-up

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