新版api mapreduce reduce结果写入mysql_MySQL

import java.io.DataInput;import java.io.DataOutput;import java.io.IOException;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Date;import java.util.Iterator;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.fs.Path;import org.apache.hadoop.io.IntWritable;import org.apache.hadoop.io.LongWritable;import org.apache.hadoop.io.Text;import org.apache.hadoop.io.Writable;import org.apache.hadoop.mapreduce.Job;import org.apache.hadoop.mapreduce.Mapper;import org.apache.hadoop.mapreduce.Reducer;import org.apache.hadoop.mapreduce.lib.db.DBConfiguration;import org.apache.hadoop.mapreduce.lib.db.DBOutputFormat;import org.apache.hadoop.mapreduce.lib.db.DBWritable;import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;/** * 将mapreduce的结果数据写入mysql中 *  * @author asheng */public class WriteDataToMysql {	/**	 * 重写DBWritable	 * 	 * @author asheng TblsWritable需要向mysql中写入数据	 */	public static class TblsWritable implements Writable, DBWritable {		String tbl_name;		String tbl_type;		public TblsWritable() {		}		public TblsWritable(String tbl_name, String tab_type) {			this.tbl_name = tbl_name;			this.tbl_type = tab_type;		}		@Override		public void write(PreparedStatement statement) throws SQLException {			statement.setString(1, this.tbl_name);			statement.setString(2, this.tbl_type);		}		@Override		public void readFields(ResultSet resultSet) throws SQLException {			this.tbl_name = resultSet.getString(1);			this.tbl_type = resultSet.getString(2);		}		@Override		public void write(DataOutput out) throws IOException {			out.writeUTF(this.tbl_name);			out.writeUTF(this.tbl_type);		}		@Override		public void readFields(DataInput in) throws IOException {			this.tbl_name = in.readUTF();			this.tbl_type = in.readUTF();		}		public String toString() {			return new String(this.tbl_name + " " + this.tbl_type);		}	}	public static class ConnMysqlMapper extends			Mapper	// TblsRecord是自定义的类型，也就是上面重写的DBWritable类	{		enum Counter {			LINESKIP,		}		private final static IntWritable one = new IntWritable(1);		public void map(LongWritable key, Text value, Context context)				throws IOException, InterruptedException {			try {				String line = value.toString();				String[] strings = line.split("/t");				String initTime = strings[1];				String devType = strings[4];				if (initTime.length() == 19) {					SimpleDateFormat sdf = new SimpleDateFormat(							"yyyy-MM-dd HH:mm:ss");					Date date = sdf.parse(initTime);					context.write(new Text(initTime.substring(0, 10)),one);				} else {					// System.err.println(initTime);					context.getCounter(Counter.LINESKIP).increment(1);				}				// } catch (ArrayIndexOutOfBoundsException e) {			} catch (ArrayIndexOutOfBoundsException e) {				context.getCounter(Counter.LINESKIP).increment(1);				return;			} catch (ParseException e) {				context.getCounter(Counter.LINESKIP).increment(1);				return;			}		}	}	public static class ConnMysqlReducer extends			Reducer {		public void reduce(Text key, Iterable values, Context context)				throws IOException, InterruptedException {			int count = 0;			for (Iterator itr = values.iterator(); itr.hasNext(); itr					.next()) {				count++;			}			context.write(					new TblsWritable(key.toString(), String.valueOf(count)),					null);		}	}	public static void main(String args[]) throws IOException,			InterruptedException, ClassNotFoundException {		Configuration conf = new Configuration();		DBConfiguration.configureDB(conf, "com.mysql.jdbc.Driver",				"jdbc:mysql://127.0.0.1:3306/XINGXUNTONG", "hadoop", "123456");		Job job = new Job(conf, "test mysql connection");		job.setJarByClass(WriteDataToMysql.class);		job.setMapperClass(ConnMysqlMapper.class);		job.setReducerClass(ConnMysqlReducer.class);		job.setOutputKeyClass(Text.class);		job.setOutputValueClass(IntWritable.class);		job.setInputFormatClass(TextInputFormat.class);		job.setOutputFormatClass(DBOutputFormat.class);		FileInputFormat.addInputPath(job, new Path(args[0]));		DBOutputFormat.setOutput(job, "test", "initTime", "new_user_total");		System.exit(job.waitForCompletion(true) ? 0 : 1);	}}

之所以写入mysql是因为我们平时处理的Tb级log文件处理结果却很小，写入关系数据库使查询和使用非常便利