Java tutorial
/** * Copyright 2007 The Apache Software Foundation * * 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.apache.hadoop.hbase; import java.io.ByteArrayOutputStream; import java.io.DataOutputStream; import java.io.IOException; import java.util.Iterator; import java.util.TreeMap; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.dfs.MiniDFSCluster; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.Path; import org.apache.hadoop.io.Text; import org.apache.hadoop.hbase.util.Writables; /** Test case for get */ public class TestGet extends HBaseTestCase { private static final Log LOG = LogFactory.getLog(TestGet.class.getName()); private static final Text CONTENTS = new Text("contents:"); private static final Text ROW_KEY = new Text(HGlobals.rootRegionInfo.regionName); private static final String SERVER_ADDRESS = "foo.bar.com:1234"; private void verifyGet(final HRegion r, final String expectedServer) throws IOException { // This should return a value because there is only one family member byte[] value = r.get(ROW_KEY, CONTENTS); assertNotNull(value); // This should not return a value because there are multiple family members value = r.get(ROW_KEY, HConstants.COLUMN_FAMILY); assertNull(value); // Find out what getFull returns TreeMap<Text, byte[]> values = r.getFull(ROW_KEY); // assertEquals(4, values.keySet().size()); for (Iterator<Text> i = values.keySet().iterator(); i.hasNext();) { Text column = i.next(); if (column.equals(HConstants.COL_SERVER)) { String server = Writables.bytesToString(values.get(column)); assertEquals(expectedServer, server); LOG.info(server); } } } /** * the test * @throws IOException */ public void testGet() throws IOException { MiniDFSCluster cluster = null; try { // Initialization cluster = new MiniDFSCluster(conf, 2, true, (String[]) null); FileSystem fs = cluster.getFileSystem(); Path dir = new Path("/hbase"); fs.mkdirs(dir); HTableDescriptor desc = new HTableDescriptor("test"); desc.addFamily(new HColumnDescriptor(CONTENTS.toString())); desc.addFamily(new HColumnDescriptor(HConstants.COLUMN_FAMILY.toString())); HRegionInfo info = new HRegionInfo(0L, desc, null, null); Path regionDir = HRegion.getRegionDir(dir, info.regionName); fs.mkdirs(regionDir); HLog log = new HLog(fs, new Path(regionDir, "log"), conf); HRegion r = new HRegion(dir, log, fs, conf, info, null); // Write information to the table long lockid = r.startUpdate(ROW_KEY); ByteArrayOutputStream bytes = new ByteArrayOutputStream(); DataOutputStream s = new DataOutputStream(bytes); CONTENTS.write(s); r.put(lockid, CONTENTS, bytes.toByteArray()); bytes.reset(); HGlobals.rootRegionInfo.write(s); r.put(lockid, HConstants.COL_REGIONINFO, Writables.getBytes(HGlobals.rootRegionInfo)); r.commit(lockid, System.currentTimeMillis()); lockid = r.startUpdate(ROW_KEY); r.put(lockid, HConstants.COL_SERVER, Writables.stringToBytes(new HServerAddress(SERVER_ADDRESS).toString())); r.put(lockid, HConstants.COL_STARTCODE, Writables.longToBytes(lockid)); r.put(lockid, new Text(HConstants.COLUMN_FAMILY + "region"), "region".getBytes(HConstants.UTF8_ENCODING)); r.commit(lockid, System.currentTimeMillis()); // Verify that get works the same from memcache as when reading from disk // NOTE dumpRegion won't work here because it only reads from disk. verifyGet(r, SERVER_ADDRESS); // Close and re-open region, forcing updates to disk r.close(); log.rollWriter(); r = new HRegion(dir, log, fs, conf, info, null); // Read it back verifyGet(r, SERVER_ADDRESS); // Update one family member and add a new one lockid = r.startUpdate(ROW_KEY); r.put(lockid, new Text(HConstants.COLUMN_FAMILY + "region"), "region2".getBytes(HConstants.UTF8_ENCODING)); String otherServerName = "bar.foo.com:4321"; r.put(lockid, HConstants.COL_SERVER, Writables.stringToBytes(new HServerAddress(otherServerName).toString())); r.put(lockid, new Text(HConstants.COLUMN_FAMILY + "junk"), "junk".getBytes(HConstants.UTF8_ENCODING)); r.commit(lockid, System.currentTimeMillis()); verifyGet(r, otherServerName); // Close region and re-open it r.close(); log.rollWriter(); r = new HRegion(dir, log, fs, conf, info, null); // Read it back verifyGet(r, otherServerName); // Close region once and for all r.close(); log.closeAndDelete(); } finally { if (cluster != null) { cluster.shutdown(); } } } }