HBase是一个分布式的、面向列的开源数据库，该技术来源于 Fay Chang 所撰写的Google论文“Bigtable：一个结构化数据的分布式存储系统”。就像Bigtable利用了Google文件系统（File System）所提供的分布式数据存储一样，HBase在Hadoop之上提供了类似于Bigtable的能力。HBase是Apache的Hadoop项目的子项目。HBase不同于一般的关系数据库，它是一个适合于非结构化数据存储的数据库。另一个不同的是HBase基于列的而不是基于行的模式。
HBase 表一般特点：
1）大：一个表可以有上亿行，上百万列
2）面向列:面向列(族)的存储和权限控制，列(族)独立检索
3）稀疏:对于为空(null)的列并不占用存储空间，表可以设计非常稀疏
Java 调用 Hbase 非关系型数据库，Hbase 中提供了相关的 Java API 访问接口便于使用，下面是本人综合网络总结的通过 Java 操作 HBase 进行创建、修改、删除表以及查询等。具体封装代码如下：
package yoodb.hbase;
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.client.Delete;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.HBaseAdmin;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.HTablePool;
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.Scan;
import org.apache.hadoop.hbase.util.Bytes;
public class HBaseTest {
// 声明静态配置
static Configuration conf = null;
static final HTablePool tablePool;
static {
conf = HBaseConfiguration.create();
conf.set("hbase.zookeeper.quorum", "yoodb");
tablePool = new HTablePool(conf, 15);
}
/*
* 创建表
* @tableName 表名
* @family 列族数组
*/
public static void creatTable(String tableName, String[] family)
throws Exception {
HBaseAdmin admin = new HBaseAdmin(conf);
HTableDescriptor desc = new HTableDescriptor(tableName);
for (int i = 0; i < family.length; i++) {
desc.addFamily(new HColumnDescriptor(family[i]));
}
if (admin.tableExists(tableName)) {
System.out.println("table Exists!");
System.exit(0);
} else {
admin.createTable(desc);
System.out.println("create table Success!");
}
}
/*
* 表添加数据
* @rowKey rowKey
* @tableName 表名
* @column1 第一个列族数组 realname
* @value1 第一个列的值的数组
* @column2 第二个列族数组 address
* @value2 第二个列的值的数组
*/
public static void addTableData(String rowKey, String tableName,String[] column1, String[] value1, String[] column2, String[] value2)
throws IOException {
Put put = new Put(Bytes.toBytes(rowKey));
HTable table = (HTable) tablePool.getTable(tableName);
HColumnDescriptor[] columnFamilies = table.getTableDescriptor()
.getColumnFamilies();
for (int i = 0; i < columnFamilies.length; i++) {
String familyName = columnFamilies[i].getNameAsString();
if (familyName.equals("realname")) {
for (int j = 0; j < column1.length; j++) {
put.add(Bytes.toBytes(familyName),Bytes.toBytes(column1[j]), Bytes.toBytes(value1[j]));
}
}
if (familyName.equals("address")) {
for (int j = 0; j < column2.length; j++) {
put.add(Bytes.toBytes(familyName),Bytes.toBytes(column2[j]), Bytes.toBytes(value2[j]));
}
}
}
table.put(put);
}
/*
* 更新表中的某一列
* @tableName 表名
* @rowKey rowKey
* @familyName 列族名
* @columnName 列名
* @value 更新后的值
*/
public static void updateTable(String tableName, String rowKey,
String familyName, String columnName, String value)
throws IOException {
HTable table = (HTable) tablePool.getTable(tableName);
Put put = new Put(Bytes.toBytes(rowKey));
put.add(Bytes.toBytes(familyName), Bytes.toBytes(columnName),Bytes.toBytes(value));
table.put(put);
System.out.println("update table Success!");
}
/*
* 根据rwokey查询
* @rowKey rowKey
* @tableName 表名
*/
public static Result getResult(String tableName, String rowKey)
throws IOException {
Get get = new Get(Bytes.toBytes(rowKey));
HTable table = (HTable) tablePool.getTable(tableName);
Result result = table.get(get);
for (KeyValue kv : result.list()) {
System.out.println("family==>" + Bytes.toString(kv.getFamily()));
System.out.println("qualifier==>" + Bytes.toString(kv.getQualifier()));
System.out.println("value==>" + Bytes.toString(kv.getValue()));
System.out.println("Timestamp==>" + kv.getTimestamp());
}
return result;
}
/*
* 遍历查询hbase表数组
* @tableName 表名
*/
public static void getResultScann(String tableName) throws IOException {
Scan scan = new Scan();
ResultScanner rs = null;
HTable table = (HTable) tablePool.getTable(tableName);
try {
rs = table.getScanner(scan);
for (Result r : rs) {
for (KeyValue kv : r.list()) {
System.out.println("family==>" + Bytes.toString(kv.getFamily()));
System.out.println("qualifier==>" + Bytes.toString(kv.getQualifier()));
System.out.println("value==>" + Bytes.toString(kv.getValue()));
System.out.println("timestamp==>" + kv.getTimestamp());
}
}
} finally {
rs.close();
}
}
/*
* 查询表中的某单一列
* @tableName 表名
* @rowKey rowKey
*/
public static void getResultByColumn(String tableName, String rowKey,
String familyName, String columnName) throws IOException {
HTable table = (HTable) tablePool.getTable(tableName);
Get get = new Get(Bytes.toBytes(rowKey));
get.addColumn(Bytes.toBytes(familyName), Bytes.toBytes(columnName)); // 获取指定列族以及列中修饰符对应列名
Result result = table.get(get);
for (KeyValue kv : result.list()) {
System.out.println("family==>" + Bytes.toString(kv.getFamily()));
System.out.println("qualifier==>" + Bytes.toString(kv.getQualifier()));
System.out.println("value==>" + Bytes.toString(kv.getValue()));
System.out.println("Timestamp==>" + kv.getTimestamp());
}
}
/*
* 查询某列数据的多个版本
* @tableName 表名
* @rowKey rowKey
* @familyName 列族名
* @columnName 列名
*/
public static void getResultByVersion(String tableName, String rowKey,
String familyName, String columnName) throws IOException {
HTable table = (HTable) tablePool.getTable(tableName);
Get get = new Get(Bytes.toBytes(rowKey));
get.addColumn(Bytes.toBytes(familyName), Bytes.toBytes(columnName));
get.setMaxVersions(5);
Result result = table.get(get);
for (KeyValue kv : result.list()) {
System.out.println("family==>" + Bytes.toString(kv.getFamily()));
System.out.println("qualifier==>" + Bytes.toString(kv.getQualifier()));
System.out.println("value==>" + Bytes.toString(kv.getValue()));
System.out.println("Timestamp==>" + kv.getTimestamp());
}
}
/*
* 删除指定的列
* @tableName 表名
* @rowKey rowKey
* @familyName 列族名
* @columnName 列名
*/
public static void deleteColumn(String tableName, String rowKey,
String falilyName, String columnName) throws IOException {
HTable table = (HTable) tablePool.getTable(tableName);
Delete deleteColumn = new Delete(Bytes.toBytes(rowKey));
deleteColumn.deleteColumns(Bytes.toBytes(falilyName),Bytes.toBytes(columnName));
table.delete(deleteColumn);
System.out.println(falilyName + "==>" + columnName + "is deleted!");
}
/*
* 删除指定的列
* @tableName 表名
* @rowKey rowKey
*/
public static void deleteAllColumn(String tableName, String rowKey) throws IOException {
HTable table = (HTable) tablePool.getTable(tableName);
Delete deleteAll = new Delete(Bytes.toBytes(rowKey));
table.delete(deleteAll);
System.out.println("all columns are deleted!");
}
/*
* 删除表
*
* @tableName 表名
*/
public static void deleteTable(String tableName) throws IOException {
HBaseAdmin admin = new HBaseAdmin(conf);
admin.disableTable(tableName);
admin.deleteTable(tableName);
System.out.println(tableName + " is deleted!");
}
}
Java Hbase main函数测试类，具体代码如下：
package com.yoodb;
public class Test {
public static void main(String[] args) throws Exception {
// 创建表
String tableName = "yoodbblog";
String[] family = { "realname","address" };
HBaseTest.creatTable(tableName,family);
// 为表添加数据
String[] column1 = { "title", "author", "content" };
String[] value1 = {"素文宅","yoodb","www.yoodb.com" };
String[] column2 = { "name", "nickname" };
String[] value2 = { "真实名称", "昵称" };
HBaseTest.addTableData("rowkey1","yoodbblog",column1, value1, column2, value2);
// 删除一列
HBaseTest.deleteColumn("yoodbblog", "rowkey1", "realname", "name");
// 删除所有列
HBaseTest.deleteAllColumn("yoodbblog", "rowkey1");
// 删除表
HBaseTest.deleteTable("yoodbblog");
// 查询
HBaseTest.getResult("yoodbblog", "rowkey1");
// 查询某一列的值
HBaseTest.getResultByColumn("yoodbblog", "rowkey1", "realname", "nickname");
// 修改某一列的值
HBaseTest.updateTable("yoodbblog", "rowkey1", "realname", "nickname","假昵称");
// 遍历表数据查询
HBaseTest.getResultScann("yoodbblog");
// 查询某列的多版本
HBaseTest.getResultByVersion("yoodbblog", "rowkey1", "realname", "name");
}
}
来源：http://blog.yoodb.com/yoodb/article/detail/1092