使用Hive或者HadoopMR访问表格存储中的表

配置表格存储作为mapper的数据源。 private static RangeRowQueryCriteria fetchCriteria() { RangeRowQueryCriteria res = new RangeRowQueryCriteria("YourTableName"); res.setMaxVersions(1); List<PrimaryKeyColumn> lower = new ArrayList<PrimaryKeyColumn>(); List<PrimaryKeyColumn> upper = new ArrayList<PrimaryKeyColumn>(); lower.add(new PrimaryKeyColumn("YourPkeyName", PrimaryKeyValue.INF_MIN)); upper.add(new PrimaryKeyColumn("YourPkeyName", PrimaryKeyValue.INF_MAX)); res.setInclusiveStartPrimaryKey(new PrimaryKey(lower)); res.setExclusiveEndPrimaryKey(new PrimaryKey(upper)); return res; } public static void main(String[] args) throws Exception { Configuration conf = new Configuration(); Job job = Job.getInstance(conf, "row count"); job.addFileToClassPath(new Path("hadoop-connector.jar")); job.setJarByClass(RowCounter.class); job.setMapperClass(RowCounterMapper.class); job.setCombinerClass(IntSumReducer.class); job.setReducerClass(IntSumReducer.class); job.setOutputKeyClass(Text.class); job.setOutputValueClass(LongWritable.class); job.setInputFormatClass(TableStoreInputFormat.class); TableStoreInputFormat.setEndpoint(job, "https://YourInstance.Region.ots.aliyuncs.com/"); TableStoreInputFormat.setCredential(job, "YourAccessKeyId", "YourAccessKeySecret"); TableStoreInputFormat.addCriteria(job, fetchCriteria()); FileOutputFormat.setOutputPath(job, new Path("output")); System.exit(job.waitForCompletion(true) ? 0 : 1); } 示例中使用job.setInputFormatClass(TableStoreInputFormat.class)将表格存储设置为数据源，除此之外，还需要：把hadoop-connector.jar部署到集群上并添加到classpath中。路径为addFileToClassPath()指定hadoop-connector.jar的本地路径。代码中假定hadoop-connector.jar在当前路径。访问表格存储需要指定入口和身份。通过TableStoreInputFormat.setEndpoint()和TableStoreInputFormat.setCredential()设置访问表格存储需要指定的Endpoint和AccessKey信息。指定一张表用来计数。