Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.cloudata.core.tablet.backup; import java.io.IOException; import org.apache.hadoop.fs.Path; import org.apache.hadoop.io.BytesWritable; import org.apache.hadoop.mapred.FileOutputFormat; import org.apache.hadoop.mapred.JobClient; import org.apache.hadoop.mapred.JobConf; import org.apache.hadoop.mapred.SequenceFileOutputFormat; import org.cloudata.core.client.CTable; import org.cloudata.core.common.conf.CloudataConf; import org.cloudata.core.fs.CloudataFileSystem; import org.cloudata.core.fs.GPath; import org.cloudata.core.parallel.hadoop.DefaultTabletInputFormat; /** * @author jindolk * */ public class BackupBinaryJob { public void runBackUp(String tableName, String outputPath) throws IOException { CloudataConf nconf = new CloudataConf(); CloudataFileSystem fs = CloudataFileSystem.get(nconf); if (fs.exists(new GPath(outputPath))) { throw new IOException("Output path already exists:" + outputPath); } if (!CTable.existsTable(nconf, tableName)) { throw new IOException("No Table:" + tableName); } CTable ctable = CTable.openTable(nconf, tableName); String columns = ""; for (String eachColumn : ctable.getTableSchema().getColumnsArray()) { columns += eachColumn + ","; } columns = columns.substring(0, columns.length() - 1); JobConf jobConf = new JobConf(BackupBinaryJob.class); jobConf.setMapperClass(BackupBinaryMap.class); jobConf.setInputFormat(BackupTabletInputFormat.class); jobConf.set(DefaultTabletInputFormat.INPUT_TABLE, tableName); jobConf.set(DefaultTabletInputFormat.INPUT_COLUMN_LIST, columns); FileOutputFormat.setOutputPath(jobConf, new Path(outputPath)); jobConf.setMapOutputKeyClass(BytesWritable.class); jobConf.setMapOutputValueClass(BytesWritable.class); jobConf.setOutputFormat(SequenceFileOutputFormat.class); //map only jobConf.setNumReduceTasks(0); JobClient.runJob(jobConf); } }