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JDBI からHBase Data のデータアクセスオブジェクトを作成

JDBI でHBase data 用のSQL オブジェクトAPIを作成する方法を概説します。

JDBI は、Fluent スタイルとSQL オブジェクトスタイルという2つの異なるスタイルAPI を公開する、Java 用のSQL コンビニエンスライブラリです。CData JDBC Driver for HBase は、Java アプリケーションとリアルタイムHBase data のデータ連携を実現します。これらの技術を組み合わせることによって、HBase data へのシンプルなコードアクセスが可能になります。ここでは、基本的なDAO(Data Access Object )とそれに付随するHBase data の読み書きのためのコードの作成について説明します。

HBase Customers Entity のDAO を作成

The interface below declares the desired behavior for the SQL object to create a single method for each SQL statement to be implemented.

public interface MyCustomersDAO { //insert new data into HBase @SqlUpdate("INSERT INTO Customers (ShipCity, Price) values (:shipCity, :price)") void insert(@Bind("shipCity") String shipCity, @Bind("price") String price); //request specific data from HBase (String type is used for simplicity) @SqlQuery("SELECT Price FROM Customers WHERE ShipCity = :shipCity") String findPriceByShipCity(@Bind("shipCity") String shipCity); /* * close with no args is used to close the connection */ void close(); }

HBase への接続を開く

Collect the necessary connection properties and construct the appropriate JDBC URL for connecting to HBase.

Set the Port and Server to connect to Apache HBase.

ビルトイン接続文字列デザイナー

For assistance in constructing the JDBC URL, use the connection string designer built into the HBase JDBC Driver.Either double-click the JAR file or execute the jar file from the command-line.

java -jar cdata.jdbc.apachehbase.jar

Fill in the connection properties and copy the connection string to the clipboard.

A connection string for HBase will typically look like the following:

jdbc:apachehbase:Server=127.0.0.1;Port=8080;

Use the configured JDBC URL to obtain an instance of the DAO interface.The particular method shown below will open a handle bound to the instance, so the instance needs to be closed explicitly to release the handle and the bound JDBC connection.

DBI dbi = new DBI("jdbc:apachehbase:Server=127.0.0.1;Port=8080;"); MyCustomersDAO dao = dbi.open(MyCustomersDAO.class); //do stuff with the DAO dao.close();

HBase Data について

With the connection open to HBase, simply call the previously defined method to retrieve data from the Customers entity in HBase.

//disply the result of our 'find' method String price = dao.findPriceByShipCity("New York"); System.out.println(price);

HBase Data の書き方

It is also simple to write data to HBase, using the previously defined method.

//add a new entry to the Customers entity dao.insert(newShipCity, newPrice);

Since the JDBI library is able to work with JDBC connections, you can easily produce a SQL Object API for HBase by integrating with the CData JDBC Driver for HBase.Download a free trial and work with live HBase data in custom Java applications today.

 
 
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