hadoop与mysql数据库的那点事(1)

　　DBMapper类:
package com.simope.mr.db;
import java.io.IOException;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.MapReduceBase;
import org.apache.hadoop.mapred.Mapper;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reporter;
public class DBMapper extends MapReduceBase implements
Mapper<LongWritable， TeacherRecord， LongWritable， Text> {
public void map(LongWritable key， TeacherRecord value，
OutputCollector<LongWritable， Text> collector， Reporter reporter)
throws IOException {
collector.collect(new LongWritable(value.id)，
new Text(value.toString()));
}
}
　　DBReducer类：
package com.simope.mr.db;
import java.io.IOException;
import java.util.Iterator;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.MapReduceBase;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reducer;
import org.apache.hadoop.mapred.Reporter;
public class DBReducer extends MapReduceBase implements Reducer<LongWritable， Text， StudentRecord， Text>{
@Override
public void reduce(LongWritable key， Iterator<Text> values，
OutputCollector<StudentRecord， Text> output， Reporter reporter)
throws IOException {
String[] InfoArr = values.next().toString().split(" ");
StudentRecord s = new StudentRecord();
//         t.id = Integer.parseInt(InfoArr[0]);  //id是自增长
s.name = InfoArr[0];
s.age = Integer.parseInt(InfoArr[1]);
s.departmentID = Integer.parseInt(InfoArr[2]);
output.collect(s， new Text(s.name));
}
}