一、Eclipse 新建Other-》Map/Reduce Project工程
工程自动包含了相关hadoop的jar包，
另外还需分别导入以下hive和连接mysql的jar包：
hive/lib/*.jar
mysql-connector-java-5.1.24-bin.jar
二、启运HiveServer
命令：bin/hive --service hiveserver &
曾经执行多次这个命令没成功后，报错：Could not create ServerSocket on address 0.0.0.0/0.0.0.0:10000.
解决办法：启动时，指定端口号，命令
bin/hive --service hiveserver -p 10002
如果没报错就不用理会，但下面代码中的端口号要改为默认的10000，与这里的一致。
三、Eclipse中java测试代码
如果新建工程时不时选择hadoop工程，会报错：Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/hadoop/io/Writable
解决办法：这是因为一下hadoop的包没有加进来，重新建一个工程，工程类型选择Other-》Map/Reduce Project工程，自动就包含了hadoop开发环境
另需先在/home/hadoop/file/目录下准备user_info.txt文件，内容如下(\t分割符)
1001 jack 30
1002 tom 25
1003 kate 20
//--------------HiveTest .java-----------------
package test;
import java.sql.SQLException;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
import java.sql.DriverManager;
public class HiveQuery {
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://192.168.1.200:10002/default", "", "");
Statement stmt = con.createStatement();
String tableName = "testHiveDriverTable";
stmt.executeQuery("drop table " + tableName);
ResultSet res = stmt.executeQuery("create table " + tableName + " (id int, name string, age string) row format delimited fields terminated by ‘\t‘ lines terminated by ‘\n‘");
// 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)+ "\t" + res.getString(3));
}
// 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 = "/home/hadoop/file/user_info.txt";
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) + "\t" + res.getString(3));
}
// 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));
}
}
}
//------------end---------------------------------------------
四、显示结果
Running: show tables ‘testHiveDriverTable‘
testhivedrivertable
Running: describe testHiveDriverTable
id int
name string
age string
Running: load data local inpath ‘/home/hadoop/file/user_info.txt‘ into table testHiveDriverTable
Running: select * from testHiveDriverTable
1001 jack 30
1002 tom 25
1003 kate 20
Running: select count(1) from testHiveDriverTable
3