Impala通過JDBC方式訪問

 

 

 　　不多說，直接上干貨！

 

 

 

 

 

 

 

• 配置：
　　– impala.driver=org.apache.hive.jdbc.HiveDriver
　　– impala.url=jdbc:hive2://node2:21050/;auth=noSasl
　　– impala.username=
　　– impala.password=

• 盡量使用PreparedStatement執行SQL語句：
　　– 1.性能上PreparedStatement要好於Statement
　　– 2.Statement存在查詢不出數據的情況

 

 

 

 

下面是Java的測試代碼：

　　首先是引入Impala所需要的類庫

　　

 

 

 

　　然后是測試代碼：

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import org.junit.Test;
public class demo {
    public static Connection getConnection() throws ClassNotFoundException, SQLException{
        String driver = "org.apache.hive.jdbc.HiveDriver";
        String url = "jdbc:hive2://node23:21050/;auth=noSasl";
        String username = "";
        String password = "";
        Connection conn = null;
        Class.forName(driver);
        conn = (Connection) DriverManager.getConnection(url,username,password);
        return conn;
    }
    @Test
    public void select() throws ClassNotFoundException, SQLException{
        Connection conn = getConnection();
        String sql = "select * from t_stu;";
        PreparedStatement ps = conn.prepareStatement(sql);
        ResultSet rs = ps.executeQuery();
        int col = rs.getMetaData().getColumnCount();
        System.out.println("=====================================");
        while (rs.next()){
            for(int i=1;i<=col;i++){
                System.out.print(rs.getString(i)+"\t");
            }
            System.out.print("\n");
        }
        System.out.println("=====================================");
    }
}

 

 

 

　　最后是測試結果：

 

 

 

 

 

 

 

 

 

更多參考

http://www.cloudera.com/content/cloudera/en/documentation/cloudera-impala/latest/topics/impala_jdbc.html