• hadoop2的mapreduce操作hbase数据


    1、从hbase中取数据,再把计算结果插入hbase中

    package com.yeliang;
    import java.io.IOException;
    
    import org.apache.hadoop.conf.Configuration;
    import org.apache.hadoop.fs.Path;
    import org.apache.hadoop.hbase.Cell;
    import org.apache.hadoop.hbase.CellUtil;
    import org.apache.hadoop.hbase.HBaseConfiguration;
    import org.apache.hadoop.hbase.HColumnDescriptor;
    import org.apache.hadoop.hbase.HTableDescriptor;
    import org.apache.hadoop.hbase.client.HBaseAdmin;
    import org.apache.hadoop.hbase.client.Put;
    import org.apache.hadoop.hbase.client.Result;
    import org.apache.hadoop.hbase.client.Scan;
    import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
    import org.apache.hadoop.hbase.mapred.TableInputFormat;
    import org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil;
    import org.apache.hadoop.hbase.mapreduce.TableMapper;
    import org.apache.hadoop.hbase.mapreduce.TableOutputFormat;
    import org.apache.hadoop.hbase.mapreduce.TableReducer;
    import org.apache.hadoop.hbase.util.Bytes;
    import org.apache.hadoop.io.IntWritable;
    import org.apache.hadoop.io.LongWritable;
    import org.apache.hadoop.io.NullWritable;
    import org.apache.hadoop.io.Text;
    import org.apache.hadoop.mapreduce.Job;
    import org.apache.hadoop.mapreduce.Mapper;
    import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
    import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
    
    /**
     * 从hbase里取数据,分析完成后插入到hbase里
     * @author liang.ye
     *
     */
    public class FamilyHBase {
    
        public static class Map extends TableMapper<Text, IntWritable>{
    
    		@Override
    		protected void map(ImmutableBytesWritable key, Result value, Context context)
    				throws IOException, InterruptedException {
    			for (Cell cell : value.rawCells())  
                {  
    				if(new String(CellUtil.cloneQualifier(cell)).equals("GroupID")){
    					context.write(new Text(new String(CellUtil.cloneValue(cell))), new IntWritable(1));
    				}
                }  
    		}
        }
    
        public static class Reduce extends
                TableReducer<Text, IntWritable, NullWritable> {
            public void reduce(Text key, Iterable<IntWritable> values,
                    Context context) throws IOException, InterruptedException {
                int sum = 0;
                for (IntWritable i : values) {
                    sum += i.get();
                }
                byte[] keyBytes = Bytes.toBytes(key.toString());
                if(keyBytes.length>0){
                	Put put = new Put(keyBytes);
                    // Put实例化,每一个词存一行
                    put.add(Bytes.toBytes("content"), Bytes.toBytes("count"),
                            Bytes.toBytes(String.valueOf(sum)));
                    // 列族为content,列为count,列值为数目
                    context.write(NullWritable.get(), put);
                }
            }
        }
    
        public static void createHBaseTable(String tableName) throws IOException {
            HTableDescriptor htd = new HTableDescriptor(tableName);
            HColumnDescriptor col = new HColumnDescriptor("content");
            htd.addFamily(col);
            Configuration conf = HBaseConfiguration.create();
            conf.set("hbase.zookeeper.quorum","192.168.56.101,192.168.56.102,192.168.56.103");
            HBaseAdmin admin = new HBaseAdmin(conf);
            if (admin.tableExists(tableName)) {
                System.out.println("table exists, trying to recreate table......");
                admin.disableTable(tableName);
                admin.deleteTable(tableName);
            }
            System.out.println("create new table:" + tableName);
            admin.createTable(htd);
        }
    
        public static void main(String[] args) throws IOException,
                InterruptedException, ClassNotFoundException {
            String tableName = "family_sum_by_groupid";
            Configuration conf = HBaseConfiguration.create();
            //conf.set("hbase.zookeeper.quorum","192.168.56.101,192.168.56.102,192.168.56.103");
            createHBaseTable(tableName);
            Job job = new Job(conf, "family_sum_by_groupid ");
            job.setJarByClass(FamilyHBase.class);
            Scan scan = new Scan();
            scan.addFamily("cf".getBytes());
            TableMapReduceUtil.initTableMapperJob("family3", scan, Map.class, Text.class, IntWritable.class, job);
            TableMapReduceUtil.initTableReducerJob(tableName, Reduce.class, job);
            System.exit(job.waitForCompletion(true) ? 0 : 1);
        }
    }
    

      2、从hdfs中取数据,把计算的结果插入到hdfs中

    import java.io.IOException;
    
    import org.apache.hadoop.conf.Configuration;
    import org.apache.hadoop.fs.Path;
    import org.apache.hadoop.hbase.HBaseConfiguration;
    import org.apache.hadoop.hbase.HColumnDescriptor;
    import org.apache.hadoop.hbase.HTableDescriptor;
    import org.apache.hadoop.hbase.client.HBaseAdmin;
    import org.apache.hadoop.hbase.client.Put;
    import org.apache.hadoop.hbase.mapreduce.TableOutputFormat;
    import org.apache.hadoop.hbase.mapreduce.TableReducer;
    import org.apache.hadoop.hbase.util.Bytes;
    import org.apache.hadoop.io.IntWritable;
    import org.apache.hadoop.io.LongWritable;
    import org.apache.hadoop.io.NullWritable;
    import org.apache.hadoop.io.Text;
    import org.apache.hadoop.mapreduce.Job;
    import org.apache.hadoop.mapreduce.Mapper;
    import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
    import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
    
    /**
     * 从hdfs中取数分析,然后插入到hbase里
     * @author liang.ye
     *
     */
    public class WordCountHBase {
    
        public static class Map extends
                Mapper<LongWritable, Text, Text, IntWritable> {
            private IntWritable i = new IntWritable(1);
    
            public void map(LongWritable key, Text value, Context context)
                    throws IOException, InterruptedException {
                String s[] = value.toString().trim().split(" ");
                // 将输入的每行以空格分开
                for (String m : s) {
                    context.write(new Text(m), i);
                }
            }
        }
    
        public static class Reduce extends
                TableReducer<Text, IntWritable, NullWritable> {
            public void reduce(Text key, Iterable<IntWritable> values,
                    Context context) throws IOException, InterruptedException {
                int sum = 0;
                for (IntWritable i : values) {
                    sum += i.get();
                }
                byte[] keyBytes = Bytes.toBytes(key.toString());
                if(keyBytes.length>0){
                	Put put = new Put(keyBytes);
                    // Put实例化,每一个词存一行
                    put.add(Bytes.toBytes("content"), Bytes.toBytes("count"),
                            Bytes.toBytes(String.valueOf(sum)));
                    // 列族为content,列为count,列值为数目
                    context.write(NullWritable.get(), put);
                }
            }
        }
    
        public static void createHBaseTable(String tableName) throws IOException {
            HTableDescriptor htd = new HTableDescriptor(tableName);
            HColumnDescriptor col = new HColumnDescriptor("content");
            htd.addFamily(col);
            Configuration conf = HBaseConfiguration.create();
            conf.set("hbase.zookeeper.quorum","192.168.56.101,192.168.56.102,192.168.56.103");
            HBaseAdmin admin = new HBaseAdmin(conf);
            if (admin.tableExists(tableName)) {
                System.out.println("table exists, trying to recreate table......");
                admin.disableTable(tableName);
                admin.deleteTable(tableName);
            }
            System.out.println("create new table:" + tableName);
            admin.createTable(htd);
        }
    
        public static void main(String[] args) throws IOException,
                InterruptedException, ClassNotFoundException {
            String tableName = "WordCount2";
            Configuration conf = new Configuration();
            conf.set(TableOutputFormat.OUTPUT_TABLE, tableName);
            createHBaseTable(tableName);
            String input = args[0];
            Job job = new Job(conf, "WordCount table with " + input);
            job.setJarByClass(WordCountHBase.class);
            job.setNumReduceTasks(3);
            job.setMapperClass(Map.class);
            job.setReducerClass(Reduce.class);
            job.setMapOutputKeyClass(Text.class);
            job.setMapOutputValueClass(IntWritable.class);
            job.setInputFormatClass(TextInputFormat.class);
            job.setOutputFormatClass(TableOutputFormat.class);
            FileInputFormat.addInputPath(job, new Path(input));
            System.exit(job.waitForCompletion(true) ? 0 : 1);
        }
    }
    

      

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  • 原文地址:https://www.cnblogs.com/mowei/p/6782132.html
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