通过Java Api与HBase交互

　　HBase提供了Java Api的访问接口，掌握这个就跟Java应用使用RDBMS时需要JDBC一样重要，下面看一下Java api创建、删除表，及记录的增删改查操作：

package 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 HBaseTest2 {

// 声明静态配置
static Configuration conf = null;
static final HTablePool tablePool;
static {
conf = HBaseConfiguration.create();
conf.set("hbase.zookeeper.quorum", "libin2");
tablePool = new HTablePool(conf, 10);
}

/*
* 创建表
*
* @tableName 表名
*
* @family 列族列表
*/
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!");
}
}

/*
* 为表添加数据（适合知道有多少列族的固定表）
*
* @rowKey rowKey
*
* @tableName 表名
*
* @column1 第一个列族列表
*
* @value1 第一个列的值的列表
*
* @column2 第二个列族列表
*
* @value2 第二个列的值的列表
*/
public static void addData(String rowKey, String tableName,
String[] column1, String[] value1, String[] column2, String[] value2)
throws IOException {
Put put = new Put(Bytes.toBytes(rowKey));// 设置rowkey
HTable table = (HTable) tablePool.getTable(tableName);// 获取表
HColumnDescriptor[] columnFamilies = table.getTableDescriptor() // 获取所有的列族
.getColumnFamilies();

for (int i = 0; i < columnFamilies.length; i++) {
String familyName = columnFamilies[i].getNameAsString(); // 获取列族名
if (familyName.equals("article")) { // article列族put数据
for (int j = 0; j < column1.length; j++) {
put.add(Bytes.toBytes(familyName),
Bytes.toBytes(column1[j]), Bytes.toBytes(value1[j]));
}
}
if (familyName.equals("author")) { // author列族put数据
for (int j = 0; j < column2.length; j++) {
put.add(Bytes.toBytes(familyName),
Bytes.toBytes(column2[j]), Bytes.toBytes(value2[j]));
}
}
}
table.put(put);
System.out.println("add data Success!");

/*
* Put put = new Put(Bytes.toBytes("rowkey1"));
* put.add(Bytes.toBytes("article"), Bytes.toBytes("title"),
* Bytes.toBytes("Head First HBase")); put.add(Bytes.toBytes("article"),
* Bytes.toBytes("content"), Bytes.toBytes(
* "HBase is the Hadoop database. Use it when you need random, realtime read/write access to your Big Data."
* )); put.add(Bytes.toBytes("article"), Bytes.toBytes("tags"),
* Bytes.toBytes("Hadoop,HBase,NoSQL"));
* put.add(Bytes.toBytes("author"), Bytes.toBytes("name"),
* Bytes.toBytes("nicholas")); put.add(Bytes.toBytes("author"),
* Bytes.toBytes("nickname"), Bytes.toBytes("lee")); HTable table = new
* HTable(conf, Bytes.toBytes("blog2"));table.put(put);
*/
}

/*
* 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);// 获取表
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());
System.out.println("-------------------------------------------");
}
return result;
}

/*
* 遍历查询hbase表
*
* @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());
System.out
.println("-------------------------------------------");
}
}
} finally {
rs.close();
}
}

/*
* 查询表中的某一列
*
* @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)); // 获取指定列族和列修饰符对应的列
// assertThat(Bytes.toString(table.get(get).list().get(0).getValue()),is("一叶渡江"));
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());
System.out.println("-------------------------------------------");
}
}

/*
* 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!");
}

/*
* 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());
System.out.println("-------------------------------------------");
}
/*
* List<?> results = table.get(get).list(); Iterator<?> it =
* results.iterator(); while (it.hasNext()) {
* System.out.println(it.next().toString()); }
*/
}

/*
* 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!");
}

public static void main(String[] args) throws Exception {

// 创建表
/*
* String tableName = "blog2"; String[] family = { "article","author" };
* creatTable(tableName,family);
*/

// 为表添加数据
/*
* String[] column1 = { "title", "content", "tag" }; String[] value1 = {
* "Head First HBase",
* "HBase is the Hadoop database. Use it when you need random, realtime read/write access to your Big Data."
* , "Hadoop,HBase,NoSQL" }; String[] column2 = { "name", "nickname" };
* String[] value2 = { "nicholas", "lee" }; addData("rowkey1", "blog2",
* column1, value1, column2, value2);
*/

// 删除一列
// deleteColumn("blog2", "rowkey1", "author", "nickname");

// 删除所有列
//deleteAllColumn("blog2", "rowkey1");

//删除表
//deleteTable("blog2");

// 查询
// getResult("blog2", "rowkey1");

// 查询某一列的值
// getResultByColumn("blog2", "rowkey1", "author", "name");
// updateTable("blog2", "rowkey1", "author", "name","bin");
// getResultByColumn("blog2", "rowkey1", "author", "name");

// 遍历查询
// getResultScann("blog2");

// 查询某列的多版本
// getResultByVersion("blog2", "rowkey1", "author", "name");
}
}

以上就是通过Java Api与HBase交互的一些常用的操作。