使用JDBC从Java连接到Hive

Question

我正在尝试从Java连接到Hive服务器1.我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:

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) + "\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";
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)) + "\t" + 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-Metoreore,service,jdbc,exec,core和更多.jar.当我编译它时,我得到这个消息:

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？

Answer 1

尝试

private static String driverName = "org.apache.hive.jdbc.HiveDriver"

代替

private static String driverName = "org.apache.hadoop.hive.jdbc.HiveDriver";

我希望你Class.forName(driverName)在代码中添加了声明

Answer 2

我想在你的问题中你说它的Hive服务器1.如果是这样,驱动程序名称和连接字符串应如下所示:

"org.apache.hadoop.hive.jdbc.HiveDriver"

jdbc:hive://localhost:10000/default", "", "")

如果您使用的是Hive服务器2,那么它应该如下所示:

org.apache.hive.jdbc.HiveDriver

jdbc:hive2://<host>:<port>/<db>

我已经使用了相同的示例,我可以在我的pom.xml中将Hive与以下依赖项连接起来

   <dependency>
        <groupId>org.apache.hive</groupId>
        <artifactId>hive-metastore</artifactId>
        <version>0.12.0-cdh5.0.0</version>
    </dependency>

    <dependency>
        <groupId>org.apache.hive</groupId>
        <artifactId>hive-service</artifactId>
        <version>0.12.0-cdh5.0.0</version>
    </dependency>

    <!-- runtime Hive -->
    <dependency>
        <groupId>org.apache.hive</groupId>
        <artifactId>hive-common</artifactId>
        <version>0.12.0-cdh5.0.0</version>
        <scope>runtime</scope>
    </dependency>

    <dependency>
        <groupId>org.apache.hive</groupId>
        <artifactId>hive-beeline</artifactId>
        <version>0.12.0-cdh5.0.0</version>
        <scope>runtime</scope>
    </dependency>

    <dependency>
        <groupId>org.apache.hive</groupId>
        <artifactId>hive-jdbc</artifactId>
        <version>0.12.0-cdh5.0.0</version>
        <scope>runtime</scope>
    </dependency>

    <dependency>
        <groupId>org.apache.hive</groupId>
        <artifactId>hive-shims</artifactId>
        <version>0.12.0-cdh5.0.0</version>
        <scope>runtime</scope>
    </dependency>

    <dependency>
        <groupId>org.apache.hive</groupId>
        <artifactId>hive-serde</artifactId>
        <version>0.12.0-cdh5.0.0</version>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.apache.hive</groupId>
        <artifactId>hive-contrib</artifactId>
        <version>0.12.0-cdh5.0.0</version>
        <scope>runtime</scope>
    </dependency>
    <dependency>