java - Required field 'client_protocol' is unset

Question

I am using Hive 0.12, and I'm trying the JDBC from apache. When I try to run the code, I get apache.thrift.TApplicationException.

import java.sql.SQLException;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
import java.sql.DriverManager;

public class HiveJdbcClient {
private static String driverName = "org.apache.hive.jdbc.HiveDriver";

/**
 * @param args
 * @throws SQLException
 */
public static void main(String[] args) throws SQLException {
    try {
        Class.forName(driverName);
    } catch (ClassNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
        System.exit(1);
    }
    //replace "hive" here with the name of the user the queries should run as
    Connection con =      DriverManager.getConnection("jdbc:hive2://localhost:10000/default", "hive", "");
    Statement stmt = con.createStatement();
    String tableName = "testHiveDriverTable";
    stmt.execute("drop table if exists " + tableName);
    stmt.execute("create table " + tableName + " (key int, value string)");
    // show tables
    String sql = "show tables '" + tableName + "'";
    System.out.println("Running: " + sql);
    ResultSet res = stmt.executeQuery(sql);
    if (res.next()) {
        System.out.println(res.getString(1));
    }
    // describe table
    sql = "describe " + tableName;
    System.out.println("Running: " + sql);
    res = stmt.executeQuery(sql);
    while (res.next()) {
        System.out.println(res.getString(1) + "" + res.getString(2));
    }

    // load data into table
    // NOTE: filepath has to be local to the hive server
    // NOTE: /tmp/a.txt is a ctrl-A separated file with two fields per line
    String filepath = "/tmp/a.txt";
    sql = "load data local inpath '" + filepath + "' into table " + tableName;
    System.out.println("Running: " + sql);
    stmt.execute(sql);

    // select * query
    sql = "select * from " + tableName;
    System.out.println("Running: " + sql);
    res = stmt.executeQuery(sql);
    while (res.next()) {
        System.out.println(String.valueOf(res.getInt(1)) + "" + res.getString(2));
    }

    // regular hive query
    sql = "select count(1) from " + tableName;
    System.out.println("Running: " + sql);
    res = stmt.executeQuery(sql);
    while (res.next()) {
        System.out.println(res.getString(1));
    }
}

}

I imported all the necessary jars, and when I try to run my code, I get the following error:

 org.apache.thrift.TApplicationException: Required field 'client_protocol' is unset!   Struct:TOpenSessionReq(client_protocol:null)

How can I fix this?

Answer 1

This indicates a version mismatch between client and server, namely that the client is newer than the server, which is your case.