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.apache.hadoop.hbase.rest.client; import java.io.IOException; import java.io.InterruptedIOException; import java.util.ArrayList; import java.util.Collection; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.Set; import java.util.TreeMap; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.classification.InterfaceAudience; import org.apache.hadoop.classification.InterfaceStability; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.hbase.Cell; import org.apache.hadoop.hbase.HBaseConfiguration; import org.apache.hadoop.hbase.HConstants; import org.apache.hadoop.hbase.HTableDescriptor; import org.apache.hadoop.hbase.KeyValue; import org.apache.hadoop.hbase.KeyValueUtil; import org.apache.hadoop.hbase.TableName; import org.apache.hadoop.hbase.client.Append; import org.apache.hadoop.hbase.client.Delete; import org.apache.hadoop.hbase.client.Durability; import org.apache.hadoop.hbase.client.Get; import org.apache.hadoop.hbase.client.HTableInterface; import org.apache.hadoop.hbase.client.Increment; import org.apache.hadoop.hbase.client.Put; import org.apache.hadoop.hbase.client.Result; import org.apache.hadoop.hbase.client.ResultScanner; import org.apache.hadoop.hbase.client.Row; import org.apache.hadoop.hbase.client.RowMutations; import org.apache.hadoop.hbase.client.Scan; import org.apache.hadoop.hbase.client.coprocessor.Batch; import org.apache.hadoop.hbase.client.coprocessor.Batch.Callback; import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp; import org.apache.hadoop.hbase.io.TimeRange; import org.apache.hadoop.hbase.ipc.CoprocessorRpcChannel; import org.apache.hadoop.hbase.rest.Constants; import org.apache.hadoop.hbase.rest.model.CellModel; import org.apache.hadoop.hbase.rest.model.CellSetModel; import org.apache.hadoop.hbase.rest.model.RowModel; import org.apache.hadoop.hbase.rest.model.ScannerModel; import org.apache.hadoop.hbase.rest.model.TableSchemaModel; import org.apache.hadoop.hbase.util.Bytes; import org.apache.hadoop.util.StringUtils; import com.google.protobuf.Descriptors; import com.google.protobuf.Message; import com.google.protobuf.Service; import com.google.protobuf.ServiceException; /** * HTable interface to remote tables accessed via REST gateway */ @InterfaceAudience.Public @InterfaceStability.Stable public class RemoteHTable implements HTableInterface { private static final Log LOG = LogFactory.getLog(RemoteHTable.class); final Client client; final Configuration conf; final byte[] name; final int maxRetries; final long sleepTime; @SuppressWarnings("rawtypes") protected String buildRowSpec(final byte[] row, final Map familyMap, final long startTime, final long endTime, final int maxVersions) { StringBuffer sb = new StringBuffer(); sb.append('/'); sb.append(Bytes.toStringBinary(name)); sb.append('/'); sb.append(Bytes.toStringBinary(row)); Set families = familyMap.entrySet(); if (families != null) { Iterator i = familyMap.entrySet().iterator(); sb.append('/'); while (i.hasNext()) { Map.Entry e = (Map.Entry) i.next(); Collection quals = (Collection) e.getValue(); if (quals == null || quals.isEmpty()) { // this is an unqualified family. append the family name and NO ':' sb.append(Bytes.toStringBinary((byte[]) e.getKey())); } else { Iterator ii = quals.iterator(); while (ii.hasNext()) { sb.append(Bytes.toStringBinary((byte[]) e.getKey())); sb.append(':'); Object o = ii.next(); // Puts use byte[] but Deletes use KeyValue if (o instanceof byte[]) { sb.append(Bytes.toStringBinary((byte[]) o)); } else if (o instanceof KeyValue) { sb.append(Bytes.toStringBinary(((KeyValue) o).getQualifier())); } else { throw new RuntimeException("object type not handled"); } if (ii.hasNext()) { sb.append(','); } } } if (i.hasNext()) { sb.append(','); } } } if (startTime >= 0 && endTime != Long.MAX_VALUE) { sb.append('/'); sb.append(startTime); if (startTime != endTime) { sb.append(','); sb.append(endTime); } } else if (endTime != Long.MAX_VALUE) { sb.append('/'); sb.append(endTime); } if (maxVersions > 1) { sb.append("?v="); sb.append(maxVersions); } return sb.toString(); } protected String buildMultiRowSpec(final byte[][] rows, int maxVersions) { StringBuilder sb = new StringBuilder(); sb.append('/'); sb.append(Bytes.toStringBinary(name)); sb.append("/multiget/"); if (rows == null || rows.length == 0) { return sb.toString(); } sb.append("?"); for (int i = 0; i < rows.length; i++) { byte[] rk = rows[i]; if (i != 0) { sb.append('&'); } sb.append("row="); sb.append(Bytes.toStringBinary(rk)); } sb.append("&v="); sb.append(maxVersions); return sb.toString(); } protected Result[] buildResultFromModel(final CellSetModel model) { List<Result> results = new ArrayList<Result>(); for (RowModel row : model.getRows()) { List<Cell> kvs = new ArrayList<Cell>(); for (CellModel cell : row.getCells()) { byte[][] split = KeyValue.parseColumn(cell.getColumn()); byte[] column = split[0]; byte[] qualifier = null; if (split.length == 1) { qualifier = HConstants.EMPTY_BYTE_ARRAY; } else if (split.length == 2) { qualifier = split[1]; } else { throw new IllegalArgumentException("Invalid familyAndQualifier provided."); } kvs.add(new KeyValue(row.getKey(), column, qualifier, cell.getTimestamp(), cell.getValue())); } results.add(Result.create(kvs)); } return results.toArray(new Result[results.size()]); } protected CellSetModel buildModelFromPut(Put put) { RowModel row = new RowModel(put.getRow()); long ts = put.getTimeStamp(); for (List<Cell> cells : put.getFamilyCellMap().values()) { for (Cell cell : cells) { KeyValue kv = KeyValueUtil.ensureKeyValue(cell); row.addCell(new CellModel(kv.getFamily(), kv.getQualifier(), ts != HConstants.LATEST_TIMESTAMP ? ts : kv.getTimestamp(), kv.getValue())); } } CellSetModel model = new CellSetModel(); model.addRow(row); return model; } /** * Constructor * @param client * @param name */ public RemoteHTable(Client client, String name) { this(client, HBaseConfiguration.create(), Bytes.toBytes(name)); } /** * Constructor * @param client * @param conf * @param name */ public RemoteHTable(Client client, Configuration conf, String name) { this(client, conf, Bytes.toBytes(name)); } /** * Constructor * @param client * @param conf * @param name */ public RemoteHTable(Client client, Configuration conf, byte[] name) { this.client = client; this.conf = conf; this.name = name; this.maxRetries = conf.getInt("hbase.rest.client.max.retries", 10); this.sleepTime = conf.getLong("hbase.rest.client.sleep", 1000); } public byte[] getTableName() { return name.clone(); } @Override public TableName getName() { return TableName.valueOf(name); } public Configuration getConfiguration() { return conf; } public HTableDescriptor getTableDescriptor() throws IOException { StringBuilder sb = new StringBuilder(); sb.append('/'); sb.append(Bytes.toStringBinary(name)); sb.append('/'); sb.append("schema"); for (int i = 0; i < maxRetries; i++) { Response response = client.get(sb.toString(), Constants.MIMETYPE_PROTOBUF); int code = response.getCode(); switch (code) { case 200: TableSchemaModel schema = new TableSchemaModel(); schema.getObjectFromMessage(response.getBody()); return schema.getTableDescriptor(); case 509: try { Thread.sleep(sleepTime); } catch (InterruptedException e) { throw (InterruptedIOException) new InterruptedIOException().initCause(e); } break; default: throw new IOException("schema request returned " + code); } } throw new IOException("schema request timed out"); } public void close() throws IOException { client.shutdown(); } public Result get(Get get) throws IOException { TimeRange range = get.getTimeRange(); String spec = buildRowSpec(get.getRow(), get.getFamilyMap(), range.getMin(), range.getMax(), get.getMaxVersions()); if (get.getFilter() != null) { LOG.warn("filters not supported on gets"); } Result[] results = getResults(spec); if (results.length > 0) { if (results.length > 1) { LOG.warn("too many results for get (" + results.length + ")"); } return results[0]; } else { return new Result(); } } public Result[] get(List<Get> gets) throws IOException { byte[][] rows = new byte[gets.size()][]; int maxVersions = 1; int count = 0; for (Get g : gets) { if (count == 0) { maxVersions = g.getMaxVersions(); } else if (g.getMaxVersions() != maxVersions) { LOG.warn("MaxVersions on Gets do not match, using the first in the list (" + maxVersions + ")"); } if (g.getFilter() != null) { LOG.warn("filters not supported on gets"); } rows[count] = g.getRow(); count++; } String spec = buildMultiRowSpec(rows, maxVersions); return getResults(spec); } private Result[] getResults(String spec) throws IOException { for (int i = 0; i < maxRetries; i++) { Response response = client.get(spec, Constants.MIMETYPE_PROTOBUF); int code = response.getCode(); switch (code) { case 200: CellSetModel model = new CellSetModel(); model.getObjectFromMessage(response.getBody()); Result[] results = buildResultFromModel(model); if (results.length > 0) { return results; } // fall through case 404: return new Result[0]; case 509: try { Thread.sleep(sleepTime); } catch (InterruptedException e) { throw (InterruptedIOException) new InterruptedIOException().initCause(e); } break; default: throw new IOException("get request returned " + code); } } throw new IOException("get request timed out"); } public boolean exists(Get get) throws IOException { LOG.warn("exists() is really get(), just use get()"); Result result = get(get); return (result != null && !(result.isEmpty())); } /** * exists(List) is really a list of get() calls. Just use get(). * @param gets list of Get to test for the existence */ public Boolean[] exists(List<Get> gets) throws IOException { LOG.warn("exists(List<Get>) is really list of get() calls, just use get()"); Boolean[] results = new Boolean[gets.size()]; for (int i = 0; i < results.length; i++) { results[i] = exists(gets.get(i)); } return results; } public void put(Put put) throws IOException { CellSetModel model = buildModelFromPut(put); StringBuilder sb = new StringBuilder(); sb.append('/'); sb.append(Bytes.toStringBinary(name)); sb.append('/'); sb.append(Bytes.toStringBinary(put.getRow())); for (int i = 0; i < maxRetries; i++) { Response response = client.put(sb.toString(), Constants.MIMETYPE_PROTOBUF, model.createProtobufOutput()); int code = response.getCode(); switch (code) { case 200: return; case 509: try { Thread.sleep(sleepTime); } catch (InterruptedException e) { throw (InterruptedIOException) new InterruptedIOException().initCause(e); } break; default: throw new IOException("put request failed with " + code); } } throw new IOException("put request timed out"); } public void put(List<Put> puts) throws IOException { // this is a trick: The gateway accepts multiple rows in a cell set and // ignores the row specification in the URI // separate puts by row TreeMap<byte[], List<Cell>> map = new TreeMap<byte[], List<Cell>>(Bytes.BYTES_COMPARATOR); for (Put put : puts) { byte[] row = put.getRow(); List<Cell> cells = map.get(row); if (cells == null) { cells = new ArrayList<Cell>(); map.put(row, cells); } for (List<Cell> l : put.getFamilyCellMap().values()) { cells.addAll(l); } } // build the cell set CellSetModel model = new CellSetModel(); for (Map.Entry<byte[], List<Cell>> e : map.entrySet()) { RowModel row = new RowModel(e.getKey()); for (Cell cell : e.getValue()) { KeyValue kv = KeyValueUtil.ensureKeyValue(cell); row.addCell(new CellModel(kv)); } model.addRow(row); } // build path for multiput StringBuilder sb = new StringBuilder(); sb.append('/'); sb.append(Bytes.toStringBinary(name)); sb.append("/$multiput"); // can be any nonexistent row for (int i = 0; i < maxRetries; i++) { Response response = client.put(sb.toString(), Constants.MIMETYPE_PROTOBUF, model.createProtobufOutput()); int code = response.getCode(); switch (code) { case 200: return; case 509: try { Thread.sleep(sleepTime); } catch (InterruptedException e) { throw (InterruptedIOException) new InterruptedIOException().initCause(e); } break; default: throw new IOException("multiput request failed with " + code); } } throw new IOException("multiput request timed out"); } public void delete(Delete delete) throws IOException { String spec = buildRowSpec(delete.getRow(), delete.getFamilyCellMap(), delete.getTimeStamp(), delete.getTimeStamp(), 1); for (int i = 0; i < maxRetries; i++) { Response response = client.delete(spec); int code = response.getCode(); switch (code) { case 200: return; case 509: try { Thread.sleep(sleepTime); } catch (InterruptedException e) { throw (InterruptedIOException) new InterruptedIOException().initCause(e); } break; default: throw new IOException("delete request failed with " + code); } } throw new IOException("delete request timed out"); } public void delete(List<Delete> deletes) throws IOException { for (Delete delete : deletes) { delete(delete); } } public void flushCommits() throws IOException { // no-op } class Scanner implements ResultScanner { String uri; public Scanner(Scan scan) throws IOException { ScannerModel model; try { model = ScannerModel.fromScan(scan); } catch (Exception e) { throw new IOException(e); } StringBuffer sb = new StringBuffer(); sb.append('/'); sb.append(Bytes.toStringBinary(name)); sb.append('/'); sb.append("scanner"); for (int i = 0; i < maxRetries; i++) { Response response = client.post(sb.toString(), Constants.MIMETYPE_PROTOBUF, model.createProtobufOutput()); int code = response.getCode(); switch (code) { case 201: uri = response.getLocation(); return; case 509: try { Thread.sleep(sleepTime); } catch (InterruptedException e) { throw (InterruptedIOException) new InterruptedIOException().initCause(e); } break; default: throw new IOException("scan request failed with " + code); } } throw new IOException("scan request timed out"); } @Override public Result[] next(int nbRows) throws IOException { StringBuilder sb = new StringBuilder(uri); sb.append("?n="); sb.append(nbRows); for (int i = 0; i < maxRetries; i++) { Response response = client.get(sb.toString(), Constants.MIMETYPE_PROTOBUF); int code = response.getCode(); switch (code) { case 200: CellSetModel model = new CellSetModel(); model.getObjectFromMessage(response.getBody()); return buildResultFromModel(model); case 204: case 206: return null; case 509: try { Thread.sleep(sleepTime); } catch (InterruptedException e) { throw (InterruptedIOException) new InterruptedIOException().initCause(e); } break; default: throw new IOException("scanner.next request failed with " + code); } } throw new IOException("scanner.next request timed out"); } @Override public Result next() throws IOException { Result[] results = next(1); if (results == null || results.length < 1) { return null; } return results[0]; } class Iter implements Iterator<Result> { Result cache; public Iter() { try { cache = Scanner.this.next(); } catch (IOException e) { LOG.warn(StringUtils.stringifyException(e)); } } @Override public boolean hasNext() { return cache != null; } @Override public Result next() { Result result = cache; try { cache = Scanner.this.next(); } catch (IOException e) { LOG.warn(StringUtils.stringifyException(e)); cache = null; } return result; } @Override public void remove() { throw new RuntimeException("remove() not supported"); } } @Override public Iterator<Result> iterator() { return new Iter(); } @Override public void close() { try { client.delete(uri); } catch (IOException e) { LOG.warn(StringUtils.stringifyException(e)); } } } public ResultScanner getScanner(Scan scan) throws IOException { return new Scanner(scan); } public ResultScanner getScanner(byte[] family) throws IOException { Scan scan = new Scan(); scan.addFamily(family); return new Scanner(scan); } public ResultScanner getScanner(byte[] family, byte[] qualifier) throws IOException { Scan scan = new Scan(); scan.addColumn(family, qualifier); return new Scanner(scan); } public boolean isAutoFlush() { return true; } public Result getRowOrBefore(byte[] row, byte[] family) throws IOException { throw new IOException("getRowOrBefore not supported"); } public boolean checkAndPut(byte[] row, byte[] family, byte[] qualifier, byte[] value, Put put) throws IOException { // column to check-the-value put.add(new KeyValue(row, family, qualifier, value)); CellSetModel model = buildModelFromPut(put); StringBuilder sb = new StringBuilder(); sb.append('/'); sb.append(Bytes.toStringBinary(name)); sb.append('/'); sb.append(Bytes.toStringBinary(put.getRow())); sb.append("?check=put"); for (int i = 0; i < maxRetries; i++) { Response response = client.put(sb.toString(), Constants.MIMETYPE_PROTOBUF, model.createProtobufOutput()); int code = response.getCode(); switch (code) { case 200: return true; case 304: // NOT-MODIFIED return false; case 509: try { Thread.sleep(sleepTime); } catch (final InterruptedException e) { throw (InterruptedIOException) new InterruptedIOException().initCause(e); } break; default: throw new IOException("checkAndPut request failed with " + code); } } throw new IOException("checkAndPut request timed out"); } public boolean checkAndPut(byte[] row, byte[] family, byte[] qualifier, CompareOp compareOp, byte[] value, Put put) throws IOException { throw new IOException("checkAndPut for non-equal comparison not implemented"); } public boolean checkAndDelete(byte[] row, byte[] family, byte[] qualifier, byte[] value, Delete delete) throws IOException { Put put = new Put(row); // column to check-the-value put.add(new KeyValue(row, family, qualifier, value)); CellSetModel model = buildModelFromPut(put); StringBuilder sb = new StringBuilder(); sb.append('/'); sb.append(Bytes.toStringBinary(name)); sb.append('/'); sb.append(Bytes.toStringBinary(row)); sb.append("?check=delete"); for (int i = 0; i < maxRetries; i++) { Response response = client.put(sb.toString(), Constants.MIMETYPE_PROTOBUF, model.createProtobufOutput()); int code = response.getCode(); switch (code) { case 200: return true; case 304: // NOT-MODIFIED return false; case 509: try { Thread.sleep(sleepTime); } catch (final InterruptedException e) { throw (InterruptedIOException) new InterruptedIOException().initCause(e); } break; default: throw new IOException("checkAndDelete request failed with " + code); } } throw new IOException("checkAndDelete request timed out"); } public boolean checkAndDelete(byte[] row, byte[] family, byte[] qualifier, CompareOp compareOp, byte[] value, Delete delete) throws IOException { throw new IOException("checkAndDelete for non-equal comparison not implemented"); } public Result increment(Increment increment) throws IOException { throw new IOException("Increment not supported"); } public Result append(Append append) throws IOException { throw new IOException("Append not supported"); } public long incrementColumnValue(byte[] row, byte[] family, byte[] qualifier, long amount) throws IOException { throw new IOException("incrementColumnValue not supported"); } public long incrementColumnValue(byte[] row, byte[] family, byte[] qualifier, long amount, Durability durability) throws IOException { throw new IOException("incrementColumnValue not supported"); } @Override public void batch(List<? extends Row> actions, Object[] results) throws IOException { throw new IOException("batch not supported"); } @Override public Object[] batch(List<? extends Row> actions) throws IOException { throw new IOException("batch not supported"); } @Override public <R> void batchCallback(List<? extends Row> actions, Object[] results, Batch.Callback<R> callback) throws IOException, InterruptedException { throw new IOException("batchCallback not supported"); } @Override public <R> Object[] batchCallback(List<? extends Row> actions, Batch.Callback<R> callback) throws IOException, InterruptedException { throw new IOException("batchCallback not supported"); } @Override public CoprocessorRpcChannel coprocessorService(byte[] row) { throw new UnsupportedOperationException("coprocessorService not implemented"); } @Override public <T extends Service, R> Map<byte[], R> coprocessorService(Class<T> service, byte[] startKey, byte[] endKey, Batch.Call<T, R> callable) throws ServiceException, Throwable { throw new UnsupportedOperationException("coprocessorService not implemented"); } @Override public <T extends Service, R> void coprocessorService(Class<T> service, byte[] startKey, byte[] endKey, Batch.Call<T, R> callable, Batch.Callback<R> callback) throws ServiceException, Throwable { throw new UnsupportedOperationException("coprocessorService not implemented"); } @Override public void mutateRow(RowMutations rm) throws IOException { throw new IOException("atomicMutation not supported"); } @Override public void setAutoFlush(boolean autoFlush) { throw new UnsupportedOperationException("setAutoFlush not implemented"); } @Override public void setAutoFlush(boolean autoFlush, boolean clearBufferOnFail) { throw new UnsupportedOperationException("setAutoFlush not implemented"); } @Override public void setAutoFlushTo(boolean autoFlush) { throw new UnsupportedOperationException("setAutoFlushTo not implemented"); } @Override public long getWriteBufferSize() { throw new UnsupportedOperationException("getWriteBufferSize not implemented"); } @Override public void setWriteBufferSize(long writeBufferSize) throws IOException { throw new IOException("setWriteBufferSize not supported"); } @Override public long incrementColumnValue(byte[] row, byte[] family, byte[] qualifier, long amount, boolean writeToWAL) throws IOException { throw new IOException("incrementColumnValue not supported"); } @Override public <R extends Message> Map<byte[], R> batchCoprocessorService(Descriptors.MethodDescriptor method, Message request, byte[] startKey, byte[] endKey, R responsePrototype) throws ServiceException, Throwable { throw new UnsupportedOperationException("batchCoprocessorService not implemented"); } @Override public <R extends Message> void batchCoprocessorService(Descriptors.MethodDescriptor method, Message request, byte[] startKey, byte[] endKey, R responsePrototype, Callback<R> callback) throws ServiceException, Throwable { throw new UnsupportedOperationException("batchCoprocessorService not implemented"); } }