新版api mapreduce reduce结果写入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 caozw */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;}@Overridepublic void write(PreparedStatement statement) throws SQLException {statement.setString(1, this.tbl_name);statement.setString(2, this.tbl_type);}@Overridepublic void readFields(ResultSet resultSet) throws SQLException {this.tbl_name = resultSet.getString(1);this.tbl_type = resultSet.getString(2);}@Overridepublic void write(DataOutput out) throws IOException {out.writeUTF(this.tbl_name);out.writeUTF(this.tbl_type);}@Overridepublic 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 extendsMapper<LongWritable, Text, Text, IntWritable>// 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 extendsReducer<Text, Text, TblsWritable, TblsWritable> {public void reduce(Text key, Iterable<Text> values, Context context)throws IOException, InterruptedException {int count = 0;for (Iterator<Text> 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