如果是DDL的操作就找HbaseAdmin.
如果是表上的增删改查的操作就找HTable.
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1 mport java.util.Arrays;
2
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.KeyValue;
8 import org.apache.hadoop.hbase.TableName;
9 import org.apache.hadoop.hbase.client.Delete;
10 import org.apache.hadoop.hbase.client.Get;
11 import org.apache.hadoop.hbase.client.HBaseAdmin;
12 import org.apache.hadoop.hbase.client.HTable;
13 import org.apache.hadoop.hbase.client.Put;
14 import org.apache.hadoop.hbase.client.Result;
15 import org.apache.hadoop.hbase.client.ResultScanner;
16 import org.apache.hadoop.hbase.client.Scan;
17 import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
18 import org.apache.hadoop.hbase.filter.Filter;
19 import org.apache.hadoop.hbase.filter.SingleColumnValueFilter;
20 import org.junit.After;
21 import org.junit.Before;
22 import org.junit.Test;
23
24 public class HBaseCRUDTest {
25
26 private HBaseAdmin hBaseAdmin;
27 private Configuration conf;
28
29 /**
30 * 对必须用的对象放在@Before中进行初始化
31 * @throws Exception
32 */
33 @Before
34 public void setUp() throws Exception{
35 /*创建conf对象的第一种方式
36 conf = new Configuration();
37 conf.set("hbase.rootdir", "hdfs://crxy99:9000/hbase");
38 conf.set("hbase.cluster.distributed", "true");
39 conf.set("hbase.zookeeper.quorum", "crxy99");
40 */
41 //创建对象的第二种方式
42 //这种方式需要再Maven的src/test/resoures目录中放置Hbase集群上的hbase-site.xml文件.
43 conf = HBaseConfiguration.create();
44
45 hBaseAdmin = new HBaseAdmin(conf);//通过Configuration对象得到HBaseAdmin对象.
46 System.out.println("-------setUp-------");
47
48 }
49
50
51 /**
52 * 是用完HBaseAdmin对象之后需要关闭.
53 * @throws Exception
54 */
55 @After
56 public void cleanUp() throws Exception {
57 hBaseAdmin.close();
58 System.out.println("-------cleanUp-----");
59 }
60
61
62 /**
63 * 打印出Hbase中所有的表.
64 * @throws Exception
65 */
66 @Test
67 @SuppressWarnings("deprecation")
68 public void testListTables() throws Exception{
69 System.out.println("------listTables------");
70 //获得Hbase中表的方法一:
71 String [] tableNames = hBaseAdmin.getTableNames();
72 System.out.println(Arrays.toString(tableNames));
73
74 //获得Hbase中表的方法二:
75 TableName[] listTables= hBaseAdmin.listTableNames();
76 System.out.println(Arrays.toString(listTables));
77
78 //获得Hbase中表的方法三(用到了HTableDescriptor对象):
79 HTableDescriptor[] listTabels2 = hBaseAdmin.listTables();
80 for (HTableDescriptor hTD : listTabels2) {
81 System.out.print(hTD.getTableName() + " ");
82 }
83 System.out.println();
84 }
85
86 /**
87 * 向HBase中增加一个表
88 */
89 @Test
90 public void testAddTable() throws Exception {
91 System.out.println("-----addTable-----");
92 HTableDescriptor desc = new HTableDescriptor("t2");//创建表的名称
93 HColumnDescriptor family = new HColumnDescriptor("cf"); //创建表的列族
94 desc.addFamily(family);//向表中添加列族 (Hbase在创建表的时候就要添加列族.)
95 /*
96 *HBase对单行做到了一个事务,hbase不支持跨行的事务
97 */
98
99 //table.checkAndPut(row, family, qualifier, value, put)
100
101 hBaseAdmin.createTable(desc);
102 }
103
104 /**
105 * 向表中插入数据
106 * 操作表中的数据就是需要操作表本身,需要用到了HTable对象.
107 */
108 @Test
109 public void testAddRecord() throws Exception {
110 HTable table = new HTable(conf, "t2");//操作上面新建的t2
111 String rowKey = "1";
112 String family = "cf";
113 //String qualifier = "name";
114 String qualifier = "age";
115 //String value = "SummerChill";
116 String value = "18";
117 Put put = new Put(rowKey.getBytes());//put对象传入的是一个"行键rowkey"
118 //HBase中存储的都是字节数组
119 //插入表中数据的时候hbase的shell操作用的put命令,JavaAPI对应的是Put对象.
120 put.add(family.getBytes(), qualifier.getBytes(), value.getBytes());
121 table.put(put);
122 table.close();
123 System.out.println("------addRecord-------");
124 }
125
126 /**
127 * 查询表中的数据
128 */
129 @SuppressWarnings("deprecation")
130 @Test
131 public void testQueryRecord() throws Exception {
132 HTable table = new HTable(conf, "t2");
133 String rowKey = "1";
134 //查询表中数据的时候HBase的shell操作用的get命令,JavaAPI对应的是Get对象.
135 Get get = new Get(rowKey.getBytes());
136 get.addColumn("cf".getBytes(), "age".getBytes());
137 Result result = table.get(get);
138 KeyValue[] keyVs = result.raw();
139 for(KeyValue kv : keyVs ){
140 byte[] qualifier = kv.getQualifier();
141 byte[] value = kv.getValue();
142 System.out.println(new String(qualifier) + "=" + new String(value));
143 }
144 table.close();
145 System.out.println("-----getRecord-----");
146 }
147
148 /**
149 * 条件查询
150 */
151 @SuppressWarnings("deprecation")
152 @Test
153 public void testQueryByCondition() throws Exception {
154 HTable table = new HTable(conf, "t2");
155 Scan scan = new Scan();
156 Filter filter = new SingleColumnValueFilter(
157 "cf".getBytes(),"age".getBytes(),
158 CompareOp.GREATER, "13".getBytes());
159 //CompareOp是一个操作的枚举常量
160 scan.setFilter(filter);
161 ResultScanner rs = table.getScanner(scan);
162
163 for (Result result : rs) {
164 KeyValue[] keyVs = result.raw();
165 for (KeyValue kv : keyVs) {
166 byte[] qualifier = kv.getQualifier();
167 byte[] value = kv.getValue();
168 System.out.print(new String(qualifier) + "=" + new String(value) + " ");
169 }
170 System.out.println();
171 }
172 table.close();
173 System.out.println("-----getRecord-----");
174 }
175
176 /**
177 * 删除表中的记录
178 */
179 @Test
180 public void testDeleteRecored() throws Exception {
181 HTable table = new HTable(conf, "t2");
182 byte[] row = "2".getBytes();
183 Delete delete = new Delete(row);
184 //删除指定的rowkey对应的某一列
185 //delete.deleteColumn("cf".getBytes(), "age".getBytes());
186 table.delete(delete);
187 table.close();
188 System.out.println("-----deleteRecord-----");
189 }
190
191 /**
192 * 删除表
193 */
194 @Test
195 public void testDropTable() throws Exception {
196 //删除表之前对表是否存在进行判断.
197 if(!hBaseAdmin.tableExists("t2")) {
198 throw new RuntimeException("Table Not Exists,你想弄啥嘞！");
199 }
200 if(hBaseAdmin.isTableEnabled("t2")) {
201 hBaseAdmin.disableTable("t2");
202 }
203 //在删除表之前必须对表设置disable,否则直接删除 会抛出异常
204 hBaseAdmin.deleteTable("t2");
205 System.out.println("-----deleteTable-----");
206 }
207
208 }
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