Hadoop 统计专利被引用次数（二）
一、在（一）中，我们计算出专利被那些专利所引用，在此基础上计算被引用的次数，不难实现。我们用两种方法来完成。代码（1）如下：
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import java.io.IOException;import org.apache.hadoop.conf.Configured;import org.apache.hadoop.fs.Path;import org.apache.hadoop.io.IntWritable;import org.apache.hadoop.io.Text;import org.apache.hadoop.mapreduce.Job;import org.apache.hadoop.mapreduce.Mapper;import org.apache.hadoop.mapreduce.Reducer;import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;import org.apache.hadoop.mapreduce.lib.input.KeyValueTextInputFormat;import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;import org.apache.hadoop.util.Tool;import org.apache.hadoop.util.ToolRunner;public class PatentCitationsCount extends Configured implements Tool{public static class PatentCitationsCountMapper extends Mapper<Text, Text, Text, IntWritable> {private final IntWritable length = new IntWritable();@Overrideprotected void map(Text key, Text value, Context context) throws IOException, InterruptedException {String[] array = value.toString().split("[,]");length.set(array.length);context.write(key, length);}}public static class PatentCitationsCountReducer extends Reducer<Text, IntWritable, Text, IntWritable> {private final IntWritable sumResult = new IntWritable();@Overrideprotected void reduce(Text key, Iterable<IntWritable> values,Context context) throws IOException, InterruptedException {int sum = 0;for (IntWritable intWritable : values) {sum += intWritable.get();}sumResult.set(sum);context.write(key, sumResult);}}@Overridepublic int run(String[] args) throws Exception {Job job = new Job(getConf());job.setJarByClass(getClass());job.setJobName("patentcitationscount");job.setMapperClass(PatentCitationsCountMapper.class);job.setReducerClass(PatentCitationsCountReducer.class);job.setCombinerClass(PatentCitationsCountReducer.class);job.setInputFormatClass(KeyValueTextInputFormat.class);job.setOutputKeyClass(TextOutputFormat.class);FileInputFormat.setInputPaths(job, new Path("/patent/test/input/patentcitationscount.txt"));FileOutputFormat.setOutputPath(job, new Path("/patent/test/outnput"));job.setOutputKeyClass(Text.class);job.setOutputValueClass(IntWritable.class);boolean success = job.waitForCompletion(true);return success ? 0 : 1;}public static void main(String[] args) throws Exception {int result = ToolRunner.run(new PatentCitationsCount(), args);System.exit(result);}}?代码2如下：
import java.io.IOException;import org.apache.hadoop.conf.Configured;import org.apache.hadoop.fs.Path;import org.apache.hadoop.io.IntWritable;import org.apache.hadoop.io.Text;import org.apache.hadoop.mapreduce.Job;import org.apache.hadoop.mapreduce.Mapper;import org.apache.hadoop.mapreduce.Reducer;import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;import org.apache.hadoop.mapreduce.lib.input.KeyValueTextInputFormat;import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;import org.apache.hadoop.util.Tool;import org.apache.hadoop.util.ToolRunner;public class PatentCitationsCountOther extends Configured implements Tool {public static class CountOtherMapper extends Mapper<Text, Text, Text, Text> {@Overrideprotected void map(Text key, Text value, Context context)throws IOException, InterruptedException {context.write(key, value);}}public static class CountOtherReducer extendsReducer<Text, Text, Text, IntWritable> {private IntWritable result = new IntWritable();@Overrideprotected void reduce(Text key, Iterable<Text> values, Context context)throws IOException, InterruptedException {int sum = 0;for (Text text : values) {String[] array = text.toString().split("[,]");sum += array.length;}result.set(sum);context.write(key, result);}}@Overridepublic int run(String[] args) throws Exception {Job job = new Job(getConf());job.setJarByClass(getClass());job.setJobName("patentcitationscountother");job.setMapperClass(CountOtherMapper.class);job.setReducerClass(CountOtherReducer.class);job.setInputFormatClass(KeyValueTextInputFormat.class);job.setOutputFormatClass(TextOutputFormat.class);job.setOutputKeyClass(Text.class);job.setOutputValueClass(IntWritable.class);FileInputFormat.setInputPaths(job, new Path("/patent/test/input/patentcitationscount.txt"));FileOutputFormat.setOutputPath(job, new Path("/patent/test/outnput"));boolean success = job.waitForCompletion(true);return success ? 0 : 1;}public static void main(String[] args) throws Exception {int result = ToolRunner.run(new PatentCitationsCountOther(), args);System.exit(result);}}?都可以实现相同的功能。但我不知道谁更好？