Java - Read & Write tables from Impala

Github Project : example-java-read-and-write-from-impala

Common part

Maven Dependencies

<dependency>
    <groupId>org.apache.hadoop</groupId>
    <artifactId>hadoop-client</artifactId>
    <version>${hadoop.version}</version>
</dependency>
<dependency>
    <groupId>org.apache.hive</groupId>
    <artifactId>hive-jdbc</artifactId>
    <version>1.2.1</version>
</dependency>

Impala Connection Url

Connection URL are like that : jdbc:hive2://impalahost:21050/database

Default port is 21050.

Init Connection

// Set JDBC Impala Driver
Class.forName(JDBC_DRIVER_NAME);
// Connect to Impala - Choose a user that has the rights to write into /user/hive/warehouse/
con = DriverManager.getConnection(connectionUrl,"hdfs","");
// Init Statement
Statement stmt = con.createStatement();

How to create an Impala table with Java?

String sqlStatementInvalidate = "INVALIDATE METADATA";
String sqlStatementDrop = "DROP TABLE IF EXISTS helloworld";
String sqlStatementCreate = "CREATE TABLE helloworld (message String) STORED AS PARQUET";

// Invalidate metadata to update changes
stmt.execute(sqlStatementInvalidate);

// Execute DROP TABLE Query
stmt.execute(sqlStatementDrop);
// Execute CREATE Query
stmt.execute(sqlStatementCreate);

How to insert data into an Impala table with Java?

String sqlStatementInsert = "INSERT INTO helloworld VALUES (\"helloworld\")";
// Execute INSERT Query
stmt.execute(sqlStatementInsert);

How to select data from an Impala table with Java?

String sqlStatementSelect = "SELECT * from helloworld";
// Execute SELECT Query
ResultSet rs = stmt.executeQuery(sqlStatementSelect);
// Process results
while(rs.next()) {
   logger.info(rs.getString(1));
}
// Invalidate metadata to update changes
stmt.execute(sqlStatementInvalidate);