Java - Read & Write tables from Impala with Security
Github Project : example-java-read-and-write-from-impala-with-security
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/;auth=PLAIN
Default port is 21050.
Init Connection
// Set JDBC Impala Driver Class.forName(JDBC_DRIVER_NAME); // Connect to Impala con = DriverManager.getConnection(connectionUrl,user,password); // 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);