20120228

1.hbase的错误master notfound exception  启动了hadoop和hbase之后等一会儿 再开shell

2.hive连接jdbc

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

public class jhive {
  private static String driverName = "org.apache.hadoop.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);
    }
    Connection con = DriverManager.getConnection("jdbc:hive://localhost:10000/default", "", "");
    Statement stmt = con.createStatement();
    String tableName = "testHiveDriverTable";
    stmt.executeQuery("drop table " + tableName);
    ResultSet res = stmt.executeQuery("create table " + tableName + " (key int, value string)");
    // show tables
    String sql = "show tables '" + tableName + "'";
    System.out.println("Running: " + sql);
    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) + "\t" + 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";
   
    System.out.println("*******************");
    sql = "load data local inpath '" + filepath + "' into table " + tableName;
    System.out.println("Running: " + sql);
    res = stmt.executeQuery(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)) + "\t" + res.getString(2));
    }

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

 示例代码如上

 

 

下面的链接为导入文件的详细说明：

http://dev.mysql.com/doc/refman/5.0/en/loading-tables.html

运行代码之前 先开启服务 hive --service hiveserver 10000

 

编译时报错可根据提示导入相应的包

参考：https://cwiki.apache.org/confluence/display/Hive/HiveClient

但是有个问题：从外部文件载入数据时，再查询显示为空值。