本文介绍了使用 JDBC 从 Java 连接到 Hive的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我正在尝试从 Java 连接到 Hive 服务器 1.我之前在这个论坛上发现了一个问题,但它对我不起作用.我正在使用此代码:
I'm trying to connect from Java to Hive server 1.I found a question time ago in this forum but it doesn't work for me.I'm using this code:
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));
}
这是指南中显示的代码.我在 .java 的同一路径中复制了 hive-metastore、service、jdbc、exec、core 和更多 .jar.当我编译它时,我得到这个消息:
That's the code shown in the guide. I've copied hive-metastore, service, jdbc, exec, core and more .jar in the same path of the .java.When I compile it, I get this msg:
java.lang.ClassNotFoundException: org.apache.hadoop.hive.jdbc.HiveDriver
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:190)
at HiveJdbcClient.main(HiveJdbcClient.java:14)
有人知道这里发生了什么吗?
Does anybody know what's happening here?
推荐答案
尝试
private static String driverName = "org.apache.hive.jdbc.HiveDriver"
代替
private static String driverName = "org.apache.hadoop.hive.jdbc.HiveDriver";
希望您在代码中添加了 Class.forName(driverName)
语句
I hope you have added Class.forName(driverName)
statement in your code
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