Java对hbase的操作



HBase提供了Java API对其进行管理，包括对表的管理、数据的操作等。
1. HBaseAdmin —— 对表的创建、删除、显示以及修改等；
  
2. HTable —— 通过HTable的实例来访问表并进行数据的操作，获取表实例如下两种方法：
   方法一：直接获取
   HTable table = new HTable(config, tableName);
   方法二：用表连接池的方式
   HTablePool pool = new HTablePool(config,1000);
   HTable table = (HTable) pool.getTable(tableName);

3.插入数据：
创建一个Put对象，并指定参数为一个行(Row)值（即指定给哪一列增加数据以及当前的时间戳等值），然后调用HTable.put(Put)。

4.获取数据
创建一个Get对象，在构造的时候传入行值，表示取第几行的数据，然后调用HTable.get(Get)。

5.删除数据
创建一个Delete对象，参数为一个行(Row)值，然后调用HTable.delete(Delete)。

6. 浏览数据
通过Scan可以对表中的行进行浏览，得到每一行的信息，比如列名，时间戳等，Scan相当于一个游标，通过next()来浏览下一个。
通过调用HTable.getScanner(Scan)来返回一个ResultScanner对象。
HTable.get(Get)和HTable.getScanner(Scan)都是返回一个Result。
Result是一个KeyValue的链表,遍历过程当中保存当前行信息。

以下是一个java对hbase的基本操作实例（hadoop-1.0.3 && hbase-0.90.3）

Java代码  

1. package tool;   
2.   
3. import java.io.IOException;   
4. import java.util.Scanner;   
5.   
6. import org.apache.hadoop.conf.Configuration;   
7. import org.apache.hadoop.hbase.HBaseConfiguration;   
8. import org.apache.hadoop.hbase.HColumnDescriptor;   
9. import org.apache.hadoop.hbase.HTableDescriptor;   
10. import org.apache.hadoop.hbase.KeyValue;   
11. import org.apache.hadoop.hbase.client.Delete;   
12. import org.apache.hadoop.hbase.client.Get;   
13. import org.apache.hadoop.hbase.client.HBaseAdmin;   
14. import org.apache.hadoop.hbase.client.HTable;   
15. import org.apache.hadoop.hbase.client.HTablePool;   
16. import org.apache.hadoop.hbase.client.Put;   
17. import org.apache.hadoop.hbase.client.Result;   
18. import org.apache.hadoop.hbase.client.ResultScanner;   
19. import org.apache.hadoop.hbase.client.Scan;   
20. import org.apache.hadoop.hbase.util.Bytes;   
21.   
22. public class Hbase {   
23.     //initial  
24.     static Configuration config = null;   
25.     static {   
26.         config = HBaseConfiguration.create();   
27.         config.set("hbase.zookeeper.quorum", "192.168.21.20, 192.168.21.21, 192.168.21.22");   
28.         config.set("hbase.zookeeper.property.clientPort", "2181");   
29.     }   
30.        
31.     //create a new table  
32.     public void createTable(String tableName, String[] familys) throws IOException {   
33.         HBaseAdmin admin = new HBaseAdmin(config);   
34.         if (admin.tableExists(tableName)) {   
35.             System.out.println(tableName + " is already exists,Please create another table!");   
36.         } else {   
37.             HTableDescriptor  desc = new HTableDescriptor(tableName);   
38.             for (int i = 0; i < familys.length; i++) {   
39.                 HColumnDescriptor family = new HColumnDescriptor(familys[i]);              
40.                 desc.addFamily(family);   
41.             }   
42.             admin.createTable(desc);   
43.             System.out.println("Create table \'" + tableName + "\' OK!");   
44.         }   
45.            
46.     }   
47.   
48.     //delete a table  
49.     public void deleteTable(String tableName) throws IOException {   
50.         HBaseAdmin admin = new HBaseAdmin(config);   
51.         if (!admin.tableExists(tableName)) {   
52.             System.out.println(tableName + " is not exists!");   
53.         } else {   
54.             Scanner s = new Scanner(System.in);   
55.             System.out.print("Are you sure to delete(y/n)?");   
56.             String str = s.nextLine();   
57.             if (str.equals("y") || str.equals("Y")) {   
58.                 admin.disableTable(tableName);   
59.                 admin.deleteTable(tableName);   
60.                 System.out.println(tableName + " is delete!");   
61.             } else {   
62.                 System.out.println(tableName + " is not delete!");   
63.             }   
64.         }          
65.     }   
66.        
67.     //Get table example  
68.     public void getTable(String tableName) throws IOException {   
69.         //Method I:  
70. //      HTable table = new HTable(config, tableName);  
71.         //Method II: better than I.  
72.         HTablePool pool = new HTablePool(config,1000);   
73.         @SuppressWarnings("unused")   
74.         HTable table = (HTable) pool.getTable(tableName);   
75.     }   
76.   
77.     //add a data  
78.     public void insertData(String tableName, String rowKey, String family, String qualifier, String value) {   
79.         try {   
80.             HTablePool pool = new HTablePool(config, 1000);   
81.             HTable table = (HTable)pool.getTable(tableName);   
82.             Put put = new Put(Bytes.toBytes(rowKey));   
83.             put.add(Bytes.toBytes(family), Bytes.toBytes(qualifier), Bytes.toBytes(value));   
84.             table.put(put);   
85.             System.out.println("insert a data successful!");   
86.         } catch (IOException e) {   
87.             e.printStackTrace();   
88.         }   
89.     }   
90.   
91.     //delete a data  
92.     public void deleteData(String tableName, String rowKey) {   
93.         try {   
94.             HTablePool pool = new HTablePool(config, 1000);   
95.             HTable table = (HTable)pool.getTable(tableName);   
96.             Delete del = new Delete(Bytes.toBytes(rowKey));   
97.             table.delete(del);   
98.             System.out.println("delete a data successful");   
99.             table.close();   
100.         } catch (IOException e) {   
101.             e.printStackTrace();   
102.         }   
103.     }   
104.   
105.     //Query all data  
106.     public void queryAll(String tableName) {   
107.         try {   
108.             HTablePool pool = new HTablePool(config, 1000);   
109.             HTable table = (HTable) pool.getTable(tableName);   
110.             Scan scan = new Scan();   
111.             ResultScanner scanner = table.getScanner(scan);   
112.   
113.             for (Result row : scanner) {   
114.                 System.out.println("\nRowkey: " + new String(row.getRow()));   
115.                 for (KeyValue kv : row.raw()) {   
116.                     System.out.print(new String(kv.getRow()) + " ");    //same as above  
117.                     System.out.print(new String(kv.getFamily()) + ":");   
118.                     System.out.print(new String(kv.getQualifier()) + " = ");   
119.                     System.out.print(new String(kv.getValue()));   
120.                     System.out.print(" timestamp = " + kv.getTimestamp() + "\n");   
121.                 }   
122.             }   
123.             table.close();   
124.         } catch (IOException e) {   
125.             e.printStackTrace();   
126.         }   
127.     }   
128.     //query by rowkey  
129.     public void queryByRowKey(String tableName, String rowKey) {   
130.         try {   
131.             HTablePool pool = new HTablePool(config, 1000);   
132.             HTable table = (HTable)pool.getTable(tableName);   
133.             Get get = new Get(rowKey.getBytes());   
134.             Result row = table.get(get);   
135.             for (KeyValue kv : row.raw()) {   
136.                 System.out.print(new String(kv.getRow()) + " ");       
137.                 System.out.print(new String(kv.getFamily()) + ":");   
138.                 System.out.print(new String(kv.getQualifier()) + " = ");   
139.                 System.out.print(new String(kv.getValue()));   
140.                 System.out.print(" timestamp = " + kv.getTimestamp() + "\n");   
141.             }   
142.             table.close();   
143.         } catch (IOException e) {   
144.             e.printStackTrace();   
145.         }   
146.     }   
147.   
148.       
149.     public static void main(String[] args) throws IOException {   
150.         Hbase hbase = new Hbase();   
151.         //Create a new table  
152.         String tableName = "test";   
153.         System.out.println("=======delete table======");   
154.         hbase.deleteTable(tableName);   
155.            
156.         System.out.println("=======create table======");   
157.         String[] familys = {"info", "scores"};         
158.         hbase.createTable(tableName, familys);   
159.            
160.         System.out.println("=======insert data=======");   
161.         //insert Jim  
162.         hbase.insertData(tableName, "Jim", "info", "sex", "male");   
163.         hbase.insertData(tableName, "Jim", "info", "age", "18");   
164.         hbase.insertData(tableName, "Jim", "scores", "Chinese", "98");   
165.         hbase.insertData(tableName, "Jim", "scores", "English", "90");   
166.         hbase.insertData(tableName, "Jim", "scores", "Math", "100");   
167.         //insert Ann  
168.         hbase.insertData(tableName, "Ann", "info", "sex", "female");   
169.         hbase.insertData(tableName, "Ann", "info", "age", "18");   
170.         hbase.insertData(tableName, "Ann", "scores", "Chinese", "97");   
171.         hbase.insertData(tableName, "Ann", "scores", "Math", "95");        
172.   
173.         System.out.println("=======query all data=======");   
174.         hbase.queryAll(tableName);   
175.            
176.         System.out.println("=======query by rowkey=======");   
177.         String rowKey = "Ann";   
178.         hbase.queryByRowKey(tableName, rowKey);   
179.            
180.         System.out.println("=======delete a data=======");   
181.         hbase.deleteData(tableName, rowKey);   
182.         hbase.queryAll(tableName);         
183.     }   
184.        
185. }  

package tool; import java.io.IOException; import java.util.Scanner; 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 Hbase { //initial static Configuration config = null; static { config = HBaseConfiguration.create(); config.set("hbase.zookeeper.quorum", "192.168.21.20, 192.168.21.21, 192.168.21.22"); config.set("hbase.zookeeper.property.clientPort", "2181"); } //create a new table public void createTable(String tableName, String[] familys) throws IOException { HBaseAdmin admin = new HBaseAdmin(config); if (admin.tableExists(tableName)) { System.out.println(tableName + " is already exists,Please create another table!"); } else { HTableDescriptor desc = new HTableDescriptor(tableName); for (int i = 0; i < familys.length; i++) { HColumnDescriptor family = new HColumnDescriptor(familys[i]); desc.addFamily(family); } admin.createTable(desc); System.out.println("Create table \'" + tableName + "\' OK!"); } } //delete a table public void deleteTable(String tableName) throws IOException { HBaseAdmin admin = new HBaseAdmin(config); if (!admin.tableExists(tableName)) { System.out.println(tableName + " is not exists!"); } else { Scanner s = new Scanner(System.in); System.out.print("Are you sure to delete(y/n)?"); String str = s.nextLine(); if (str.equals("y") || str.equals("Y")) { admin.disableTable(tableName); admin.deleteTable(tableName); System.out.println(tableName + " is delete!"); } else { System.out.println(tableName + " is not delete!"); } } } //Get table example public void getTable(String tableName) throws IOException { //Method I: // HTable table = new HTable(config, tableName); //Method II: better than I. HTablePool pool = new HTablePool(config,1000); @SuppressWarnings("unused") HTable table = (HTable) pool.getTable(tableName); } //add a data public void insertData(String tableName, String rowKey, String family, String qualifier, String value) { try { HTablePool pool = new HTablePool(config, 1000); HTable table = (HTable)pool.getTable(tableName); Put put = new Put(Bytes.toBytes(rowKey)); put.add(Bytes.toBytes(family), Bytes.toBytes(qualifier), Bytes.toBytes(value)); table.put(put); System.out.println("insert a data successful!"); } catch (IOException e) { e.printStackTrace(); } } //delete a data public void deleteData(String tableName, String rowKey) { try { HTablePool pool = new HTablePool(config, 1000); HTable table = (HTable)pool.getTable(tableName); Delete del = new Delete(Bytes.toBytes(rowKey)); table.delete(del); System.out.println("delete a data successful"); table.close(); } catch (IOException e) { e.printStackTrace(); } } //Query all data public void queryAll(String tableName) { try { HTablePool pool = new HTablePool(config, 1000); HTable table = (HTable) pool.getTable(tableName); Scan scan = new Scan(); ResultScanner scanner = table.getScanner(scan); for (Result row : scanner) { System.out.println("\nRowkey: " + new String(row.getRow())); for (KeyValue kv : row.raw()) { System.out.print(new String(kv.getRow()) + " "); //same as above System.out.print(new String(kv.getFamily()) + ":"); System.out.print(new String(kv.getQualifier()) + " = "); System.out.print(new String(kv.getValue())); System.out.print(" timestamp = " + kv.getTimestamp() + "\n"); } } table.close(); } catch (IOException e) { e.printStackTrace(); } } //query by rowkey public void queryByRowKey(String tableName, String rowKey) { try { HTablePool pool = new HTablePool(config, 1000); HTable table = (HTable)pool.getTable(tableName); Get get = new Get(rowKey.getBytes()); Result row = table.get(get); for (KeyValue kv : row.raw()) { System.out.print(new String(kv.getRow()) + " "); System.out.print(new String(kv.getFamily()) + ":"); System.out.print(new String(kv.getQualifier()) + " = "); System.out.print(new String(kv.getValue())); System.out.print(" timestamp = " + kv.getTimestamp() + "\n"); } table.close(); } catch (IOException e) { e.printStackTrace(); } } public static void main(String[] args) throws IOException { Hbase hbase = new Hbase(); //Create a new table String tableName = "test"; System.out.println("=======delete table======"); hbase.deleteTable(tableName); System.out.println("=======create table======"); String[] familys = {"info", "scores"}; hbase.createTable(tableName, familys); System.out.println("=======insert data======="); //insert Jim hbase.insertData(tableName, "Jim", "info", "sex", "male"); hbase.insertData(tableName, "Jim", "info", "age", "18"); hbase.insertData(tableName, "Jim", "scores", "Chinese", "98"); hbase.insertData(tableName, "Jim", "scores", "English", "90"); hbase.insertData(tableName, "Jim", "scores", "Math", "100"); //insert Ann hbase.insertData(tableName, "Ann", "info", "sex", "female"); hbase.insertData(tableName, "Ann", "info", "age", "18"); hbase.insertData(tableName, "Ann", "scores", "Chinese", "97"); hbase.insertData(tableName, "Ann", "scores", "Math", "95"); System.out.println("=======query all data======="); hbase.queryAll(tableName); System.out.println("=======query by rowkey======="); String rowKey = "Ann"; hbase.queryByRowKey(tableName, rowKey); System.out.println("=======delete a data======="); hbase.deleteData(tableName, rowKey); hbase.queryAll(tableName); } }

程序运行结果：
=======delete table======
Are you sure to delete(y/n)?y
test is delete!
=======create table======
Create table 'test' OK!
=======insert data=======
insert a data successful!
=======query all data=======
Rowkey: Ann
Ann info:age = 18 timestamp = 1349857967109
Ann info:sex = female timestamp = 1349857967080
Ann scores:Chinese = 97 timestamp = 1349857967134
Ann scores:Math = 95 timestamp = 1349857967160

Rowkey: Jim
Jim info:age = 18 timestamp = 1349857966936
Jim info:sex = male timestamp = 1349857966908
Jim scores:Chinese = 98 timestamp = 1349857966961
Jim scores:English = 90 timestamp = 1349857967002
Jim scores:Math = 100 timestamp = 1349857967052
=======query by rowkey=======
Ann info:age = 18 timestamp = 1349857967109
Ann info:sex = female timestamp = 1349857967080
Ann scores:Chinese = 97 timestamp = 1349857967134
Ann scores:Math = 95 timestamp = 1349857967160
=======delete a data=======
delete a data successful
Rowkey: Jim
Jim info:age = 18 timestamp = 1349857966936
Jim info:sex = male timestamp = 1349857966908
Jim scores:Chinese = 98 timestamp = 1349857966961
Jim scores:English = 90 timestamp = 1349857967002
Jim scores:Math = 100 timestamp = 1349857967052