HBase 开发：利用Java操作HBase

1、实战简介

HBase和Hadoop一样，都是用Java举行开发的，本次实训我们就来学习如何利用Java编写代码来操作HBase数据库。

1. 实验环境：
2. hadoop-2.7
3. JDK8.0
4. HBase2.1.1

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 2、任务

1、第1关：创建表 

1. package step1;
2. import java.io.IOException;
3. import org.apache.hadoop.conf.Configuration;
4. import org.apache.hadoop.hbase.HBaseConfiguration;
5. import org.apache.hadoop.hbase.HColumnDescriptor;
6. import org.apache.hadoop.hbase.HTableDescriptor;
7. import org.apache.hadoop.hbase.TableName;
8. import org.apache.hadoop.hbase.client.Admin;
9. import org.apache.hadoop.hbase.client.ColumnFamilyDescriptor;
10. import org.apache.hadoop.hbase.client.ColumnFamilyDescriptorBuilder;
11. import org.apache.hadoop.hbase.client.Connection;
12. import org.apache.hadoop.hbase.client.ConnectionFactory;
13. import org.apache.hadoop.hbase.client.Get;
14. import org.apache.hadoop.hbase.client.Put;
15. import org.apache.hadoop.hbase.client.Result;
16. import org.apache.hadoop.hbase.client.ResultScanner;
17. import org.apache.hadoop.hbase.client.Scan;
18. import org.apache.hadoop.hbase.client.Table;
19. import org.apache.hadoop.hbase.client.TableDescriptor;
20. import org.apache.hadoop.hbase.client.TableDescriptorBuilder;
21. import org.apache.hadoop.hbase.util.Bytes;
22. /**
23. * HBase 1.0 version of ExampleClient that uses {@code Connection},
24. * {@code Admin} and {@code Table}.
25. */
26. public class Task{
27. public void createTable()throws Exception{
28. /********* Begin *********/
29. Configuration config = HBaseConfiguration.create();
30. Connection connection = ConnectionFactory.createConnection(config);
31. try {
32. // Create table
33. Admin admin = connection.getAdmin();
34. try {
35. TableName tableName = TableName.valueOf("dept");
36. // 新 API 构建表
37. // TableDescriptor 对象通过 TableDescriptorBuilder 构建；
38. TableDescriptorBuilder tableDescriptor =
39. TableDescriptorBuilder.newBuilder(tableName);
40. ColumnFamilyDescriptor family =
41. ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes("data")).build();// 构建列族对象
42. tableDescriptor.setColumnFamily(family); // 设置列族
43. admin.createTable(tableDescriptor.build()); // 创建表
46. TableName emp = TableName.valueOf("emp");
47. // 新 API 构建表
48. // TableDescriptor 对象通过 TableDescriptorBuilder 构建；
49. TableDescriptorBuilder empDescriptor =
50. TableDescriptorBuilder.newBuilder(emp);
51. ColumnFamilyDescriptor empfamily =
52. ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes("emp")).build();// 构建列族对象
53. empDescriptor.setColumnFamily(empfamily); // 设置列族
54. admin.createTable(empDescriptor.build()); // 创建表
55. } finally {
56. admin.close();
57. }
58. } finally {
59. connection.close();
60. }
61. /********* End *********/
62. }
63. }

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1. 命令行：
3. start-dfs.sh （ Hadoop 启动）
4. 回车
5. start-hbase.sh （ hbase 启动）

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2、第2关：添加数据

1. package step2;
2. import java.io.IOException;
3. import org.apache.hadoop.conf.Configuration;
4. import org.apache.hadoop.hbase.HBaseConfiguration;
5. import org.apache.hadoop.hbase.HColumnDescriptor;
6. import org.apache.hadoop.hbase.HTableDescriptor;
7. import org.apache.hadoop.hbase.TableName;
8. import org.apache.hadoop.hbase.client.Admin;
9. import org.apache.hadoop.hbase.client.ColumnFamilyDescriptor;
10. import org.apache.hadoop.hbase.client.ColumnFamilyDescriptorBuilder;
11. import org.apache.hadoop.hbase.client.Connection;
12. import org.apache.hadoop.hbase.client.ConnectionFactory;
13. import org.apache.hadoop.hbase.client.Get;
14. import org.apache.hadoop.hbase.client.Put;
15. import org.apache.hadoop.hbase.client.Result;
16. import org.apache.hadoop.hbase.client.ResultScanner;
17. import org.apache.hadoop.hbase.client.Scan;
18. import org.apache.hadoop.hbase.client.Table;
19. import org.apache.hadoop.hbase.client.TableDescriptor;
20. import org.apache.hadoop.hbase.client.TableDescriptorBuilder;
21. import org.apache.hadoop.hbase.util.Bytes;
22. public class Task {
23. public void insertInfo()throws Exception{
24. /********* Begin *********/
25. Configuration config = HBaseConfiguration.create();
26. Connection connection = ConnectionFactory.createConnection(config);
27. Admin admin = connection.getAdmin();
28. TableName tableName = TableName.valueOf("tb_step2");
29. TableDescriptorBuilder tableDescriptor = TableDescriptorBuilder.newBuilder(tableName);
30. ColumnFamilyDescriptor family = ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes("data")).build();//  构建列族对象
31. tableDescriptor.setColumnFamily(family); //  设置列族
32. admin.createTable(tableDescriptor.build()); //  创建表
33. // 添加数据
34. byte[] row1 = Bytes.toBytes("row1");
35. Put put1 = new Put(row1);
36. byte[] columnFamily1 = Bytes.toBytes("data"); // 列
37. byte[] qualifier1 = Bytes.toBytes(String.valueOf(1)); // 列族修饰词
38. byte[] value1 = Bytes.toBytes("张三丰"); // 值
39. put1.addColumn(columnFamily1, qualifier1, value1);
40. byte[] row2 = Bytes.toBytes("row2");
41. Put put2 = new Put(row2);
42. byte[] columnFamily2 = Bytes.toBytes("data"); // 列
43. byte[] qualifier2 = Bytes.toBytes(String.valueOf(2)); // 列族修饰词
44. byte[] value2 = Bytes.toBytes("张无忌"); // 值
45. put2.addColumn(columnFamily2, qualifier2, value2);
46. Table table = connection.getTable(tableName);
47. table.put(put1);
48. table.put(put2);
49. /********* End *********/
50. }
51. }

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3、第3关：获取数据

1. package step3;
2. import java.io.IOException;
3. import org.apache.hadoop.conf.Configuration;
4. import org.apache.hadoop.hbase.HBaseConfiguration;
5. import org.apache.hadoop.hbase.HColumnDescriptor;
6. import org.apache.hadoop.hbase.HTableDescriptor;
7. import org.apache.hadoop.hbase.TableName;
8. import org.apache.hadoop.hbase.client.Admin;
9. import org.apache.hadoop.hbase.client.ColumnFamilyDescriptor;
10. import org.apache.hadoop.hbase.client.ColumnFamilyDescriptorBuilder;
11. import org.apache.hadoop.hbase.client.Connection;
12. import org.apache.hadoop.hbase.client.ConnectionFactory;
13. import org.apache.hadoop.hbase.client.Get;
14. import org.apache.hadoop.hbase.client.Put;
15. import org.apache.hadoop.hbase.client.Result;
16. import org.apache.hadoop.hbase.client.ResultScanner;
17. import org.apache.hadoop.hbase.client.Scan;
18. import org.apache.hadoop.hbase.client.Table;
19. import org.apache.hadoop.hbase.client.TableDescriptor;
20. import org.apache.hadoop.hbase.client.TableDescriptorBuilder;
21. import org.apache.hadoop.hbase.util.Bytes;
22. public class Task {
23. public void queryTableInfo()throws Exception{
24. /********* Begin *********/
25. Configuration config = HBaseConfiguration.create();
26. Connection connection = ConnectionFactory.createConnection(config);
27. Admin admin = connection.getAdmin();
28. TableName tableName = TableName.valueOf("t_step3");
29. Table table = connection.getTable(tableName);
30. // 获取数据
31. Get get = new Get(Bytes.toBytes("row1")); // 定义 get 对象
32. Result result = table.get(get); // 通过 table 对象获取数据
33. //System.out.println("Result: " + result);
34. // 很多时候我们只需要获取“值”   这里表示获取  data:1  列族的值
35. byte[] valueBytes = result.getValue(Bytes.toBytes("data"), Bytes.toBytes("1")); // 获取到的是字节数组
36. // 将字节转成字符串
37. String valueStr = new String(valueBytes,"utf-8");
38. System.out.println("value:" + valueStr);
39. TableName tableStep3Name = TableName.valueOf("table_step3");
40. Table step3Table = connection.getTable(tableStep3Name);
41. // 批量查询
42. Scan scan = new Scan();
43. ResultScanner scanner = step3Table.getScanner(scan);
44. try {
45. int i = 0;
46. for (Result scannerResult: scanner) {
47. //byte[] value = scannerResult.getValue(Bytes.toBytes("data"), Bytes.toBytes(1));
48. // System.out.println("Scan: " + scannerResult);
49. byte[] row = scannerResult.getRow();
50. System.out.println("rowName:" + new String(row,"utf-8"));
51. }
52. } finally {
53. scanner.close();
54. }
55. /********* End *********/
56. }
57. }

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4、第4关：删除表

1. package step4;
2. import java.io.IOException;
3. import org.apache.hadoop.conf.Configuration;
4. import org.apache.hadoop.hbase.HBaseConfiguration;
5. import org.apache.hadoop.hbase.HColumnDescriptor;
6. import org.apache.hadoop.hbase.HTableDescriptor;
7. import org.apache.hadoop.hbase.TableName;
8. import org.apache.hadoop.hbase.client.Admin;
9. import org.apache.hadoop.hbase.client.ColumnFamilyDescriptor;
10. import org.apache.hadoop.hbase.client.ColumnFamilyDescriptorBuilder;
11. import org.apache.hadoop.hbase.client.Connection;
12. import org.apache.hadoop.hbase.client.ConnectionFactory;
13. import org.apache.hadoop.hbase.client.Get;
14. import org.apache.hadoop.hbase.client.Put;
15. import org.apache.hadoop.hbase.client.Result;
16. import org.apache.hadoop.hbase.client.ResultScanner;
17. import org.apache.hadoop.hbase.client.Scan;
18. import org.apache.hadoop.hbase.client.Table;
19. import org.apache.hadoop.hbase.client.TableDescriptor;
20. import org.apache.hadoop.hbase.client.TableDescriptorBuilder;
21. import org.apache.hadoop.hbase.util.Bytes;
22. public class Task {
23. public void deleteTable()throws Exception{
24. /********* Begin *********/
25. Configuration config = HBaseConfiguration.create();
26. Connection connection = ConnectionFactory.createConnection(config);
27. Admin admin = connection.getAdmin();
28. TableName tableName = TableName.valueOf("t_step4");
29. admin.disableTable(tableName);
30. admin.deleteTable(tableName);
31. /********* End *********/
32. }
33. }

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