HbaseAPI學習

hbaseAPI測試

pom.xml

<dependencies>
    <dependency>
        <groupId>org.apache.hbase</groupId>
        <artifactId>hbase-server</artifactId>
        <version>1.3.1</version>
    </dependency>

    <dependency>
        <groupId>org.apache.hbase</groupId>
        <artifactId>hbase-client</artifactId>
        <version>1.3.1</version>
    </dependency>
</dependencies>

public class TestHbaseAPI_01 {
    public static void main(String[] args) {

        //構建config配置對象
        Configuration conf = HBaseConfiguration.create();
        try {
            //獲取hbase連接對象
            Connection conn = ConnectionFactory.createConnection(conf);
            //System.out.println(conn);

            //獲取操作對象:Admin
            // HBaseAdmin admin = new HBaseAdmin(conn);
            Admin admin = conn.getAdmin();

            //操作數據庫
            //判斷命名空間是否存在
            try {
                NamespaceDescriptor nameSpace = admin.getNamespaceDescriptor("wjy");
            } catch (NamespaceNotFoundException e) {
                //創建表空間
                NamespaceDescriptor nd = NamespaceDescriptor.create("wjy").build();
                admin.createNamespace(nd);
            }

            //判斷表是否存在
            TableName tableName = TableName.valueOf("wjy:student");
            boolean flag = admin.tableExists(tableName);
            if (flag) {
                //存在表，操作表
                //指定表對對象
                Table table = conn.getTable(tableName);
                //查詢數據
                Get get = new Get(Bytes.toBytes("1001"));
                Result result = table.get(get);
                if (!result.isEmpty()) {
                    System.out.println(Bytes.toString(result.getRow()));
                    System.out.println(Bytes.toString(result.getValue(Bytes.toBytes("cf"),Bytes.toBytes("name"))));
                }
            } else {
                //不存在，創建表
                //創建表描述
                HTableDescriptor tb = new HTableDescriptor(tableName);
                //增加列族信息
                HColumnDescriptor cf = new HColumnDescriptor("cf");
                tb.addFamily(cf);
                //創建
                admin.createTable(tb);
            }

            //獲取操作的結果
            //關閉數據庫連接

        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

命令行查詢數據：hbase(main):006:0> scan  'wjy:student'
ROW                                                   COLUMN+CELL                                                                                                                                                
 1001                                                 column=cf:name, timestamp=1584708637639, value=wjy                                                                                                         
1 row(s) in 0.0250 seconds
 

 

IDEA結果輸出
log4j:WARN No appenders could be found for logger (org.apache.hadoop.security.Groups).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
1001
wjy

Process finished with exit code 0