/**
* 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.hql;
import java.io.IOException;
import java.io.Writer;
import java.util.ArrayList;
import java.util.List;
import org.apache.hadoop.hbase.HBaseAdmin;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HConnection;
import org.apache.hadoop.hbase.HConnectionManager;
import org.apache.hadoop.hbase.HTable;
import org.apache.hadoop.io.Text;
/**
* Deletes values from tables.
*/
public class DeleteCommand extends BasicCommand {
public DeleteCommand(Writer o) {
super(o);
}
private Text tableName;
private Text rowKey;
private List<String> columnList;
public ReturnMsg execute(HBaseConfiguration conf) {
if (columnList == null) {
throw new IllegalArgumentException("Column list is null");
}
try {
HConnection conn = HConnectionManager.getConnection(conf);
if (!conn.tableExists(tableName)) {
return new ReturnMsg(0, "'" + tableName + "'" + TABLE_NOT_FOUND);
}
HBaseAdmin admin = new HBaseAdmin(conf);
HTable hTable = new HTable(conf, tableName);
if (rowKey != null) {
long lockID = hTable.startUpdate(rowKey);
for (Text column : getColumnList(admin, hTable)) {
hTable.delete(lockID, new Text(column));
}
hTable.commit(lockID);
} else {
admin.disableTable(tableName);
for (Text column : getColumnList(admin, hTable)) {
admin.deleteColumn(tableName, new Text(column));
}
admin.enableTable(tableName);
}
return new ReturnMsg(1, "Column(s) deleted successfully.");
} catch (IOException e) {
String[] msg = e.getMessage().split("[\n]");
return new ReturnMsg(0, msg[0]);
}
}
public void setTable(String tableName) {
this.tableName = new Text(tableName);
}
public void setRow(String row) {
this.rowKey = new Text(row);
}
/**
* Sets the column list.
*
* @param columnList
*/
public void setColumnList(List<String> columnList) {
this.columnList = columnList;
}
/**
* @param admin
* @param hTable
* @return return the column list.
*/
public Text[] getColumnList(HBaseAdmin admin, HTable hTable) {
Text[] columns = null;
try {
if (columnList.contains("*")) {
columns = hTable.getRow(new Text(this.rowKey)).keySet().toArray(
new Text[] {});
} else {
List<Text> tmpList = new ArrayList<Text>();
for (int i = 0; i < columnList.size(); i++) {
Text column = null;
if (columnList.get(i).contains(":"))
column = new Text(columnList.get(i));
else
column = new Text(columnList.get(i) + ":");
tmpList.add(column);
}
columns = tmpList.toArray(new Text[] {});
}
} catch (IOException e) {
e.printStackTrace();
}
return columns;
}
@Override
public CommandType getCommandType() {
return CommandType.DELETE;
}
}