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目录一、需求二、步骤三、结果一、需求 把以下txt中含“baidu”字符串的链接输出到一个文件,否则输出到另外一个文件。 二、步骤 1.LogMapper.java pa
把以下txt中含“baidu”字符串的链接输出到一个文件,否则输出到另外一个文件。
1.LogMapper.java
package com.whj.mapReduce.outputfORMat;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
import java.io.IOException;
public class LogMapper extends Mapper<LongWritable,Text,Text,NullWritable> {
@Override
protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
// 不做任何处理
context.write(value,NullWritable.get());
}
}
2.LogReducer.java
package com.whj.mapreduce.outputformat;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Reducer;
import java.io.IOException;
public class LogReducer extends Reducer<Text,NullWritable,Text,NullWritable> {
@Override
protected void reduce(Text key, Iterable<NullWritable> values, Context context) throws IOException, InterruptedException {
for (NullWritable value : values) {
context.write(key,NullWritable.get());
}
}
}
3.LogOutputFormat.java
package com.whj.mapreduce.outputformat;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.RecordWriter;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import java.io.IOException;
public class LoGoutputFormat extends FileOutputFormat<Text,NullWritable> {
@Override
public RecordWriter<Text, NullWritable> getRecordWriter(TaskAttemptContext job) throws IOException, InterruptedException {
LogRecordWriter lrw = new LogRecordWriter(job);
return lrw;
}
}
4.LogRecordWriter.java
package com.whj.mapreduce.outputformat;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.RecordWriter;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import java.io.IOException;
public class LogRecordWriter extends RecordWriter<Text,NullWritable> {
private FSDataOutputStream baiduOut;//ctrl+alt+f
private FSDataOutputStream otherOut;
public LogRecordWriter(TaskAttemptContext job) throws IOException {
//创建两条流
FileSystem fs = FileSystem.get(job.getConfiguration());
baiduOut = fs.create(new Path("D:\\temp\\outputformat.log"));
otherOut = fs.create(new Path("D:\\temp\\other.log"));
}
@Override
public void write(Text key, NullWritable nullWritable) throws IOException, InterruptedException {
// 具体写
String log = key.toString();
if(log.contains("baidu")){
baiduOut.writeBytes(log+"\n");
}else{
otherOut.writeBytes(log+"\n");
}
}
@Override
public void close(TaskAttemptContext taskAttemptContext) throws IOException, InterruptedException {
//关流
IOUtils.closeStream(baiduOut);
IOUtils.closeStream(otherOut);
}
}
5.LogDriver.java
package com.whj.mapreduce.outputformat;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import java.io.IOException;
public class LogDriver {
public static void main(String[] args) throws IOException, ClassNotFoundException, InterruptedException {
Configuration conf = new Configuration();
Job job = Job.getInstance(conf);
job.setjarByClass(LogDriver.class);
job.setMapperClass(LogMapper.class);
job.setReducerClass(LogReducer.class);
job.setMapOutpuTKEyClass(Text.class);
job.setMapOutputValueClass(NullWritable.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(NullWritable.class);
//设置自定义的 outputformat
job.setOutputFormatClass(LogOutputFormat.class);
FileInputFormat.setInputPaths(job, new Path("D:\\input"));
// 虽 然 我 们 自 定 义 了 outputformat , 但 是 因 为 我 们 的 outputformat 继承自fileoutputformat
//而 fileoutputformat 要输出一个_SUCCESS 文件,所以在这还得指定一个输出目录
FileOutputFormat.setOutputPath(job, new Path("D:\\temp\\logoutput"));
boolean b = job.waitForCompletion(true);
System.exit(b ? 0 : 1);
} }
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