HBase的JavaAPI操作

  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 }