如何在 Java 中执行 Sqoop? [英] How can I execute Sqoop in Java?

问题描述

我创建了一个新的 Java 项目，然后添加了 Library Sqoop 和 Hadoop.(库是hadoop-core-1.1.1.jar、sqoop-1.4.2.jar 等......".)

I created a new Java project, then I added Library Sqoop and Hadoop. (The Libraries are "hadoop-core-1.1.1.jar, sqoop-1.4.2.jar, etc.... ".)

然后我尝试了以下代码:

Then I tried below code:

public class MySqoopDriver {
    public static void main(String[] args) {
        String[] str = { "export", "--connect", "jdbc:mysql://localhost/mytestdb", "--hadoop-home",
                "/home/yoonhok/development/hadoop-1.1.1", "--table", "tbl_1", "--export-dir", "hdfs://localhost:9000/user/hive/warehouse/tbl_1",
                "--username", "yoonhok", "--password", "1234"};

        Sqoop.runTool(str);
    }
}

参数正确，因为当我在终端中尝试时，它运行良好.

The parameters are right, since when I try in terminal, it works well.

但是没有用.错误信息是:

But it didn't work. The error message is:

13/02/17 16:23:07 WARN tool.BaseSqoopTool: Setting your password on the command-line is insecure. Consider using -P instead.
13/02/17 16:23:07 INFO manager.MySQLManager: Preparing to use a MySQL streaming resultset.
13/02/17 16:23:07 INFO tool.CodeGenTool: Beginning code generation
13/02/17 16:23:07 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `tbl_1` AS t LIMIT 1
13/02/17 16:23:07 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `tbl_1` AS t LIMIT 1
13/02/17 16:23:07 INFO orm.CompilationManager: HADOOP_HOME is /home/yoonhok/development/hadoop-1.1.1
Note: /tmp/sqoop-yoonhok/compile/86a3cab62184ad50a3ae11e7cb0e4f4d/tbl_1.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
13/02/17 16:23:08 INFO orm.CompilationManager: Writing jar file: /tmp/sqoop-yoonhok/compile/86a3cab62184ad50a3ae11e7cb0e4f4d/tbl_1.jar
13/02/17 16:23:08 INFO mapreduce.ExportJobBase: Beginning export of tbl_1
13/02/17 16:23:09 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
13/02/17 16:23:09 INFO input.FileInputFormat: Total input paths to process : 1
13/02/17 16:23:09 INFO input.FileInputFormat: Total input paths to process : 1
13/02/17 16:23:09 INFO mapred.JobClient: Cleaning up the staging area file:/tmp/hadoop-yoonhok/mapred/staging/yoonhok1526809600/.staging/job_local_0001
13/02/17 16:23:09 ERROR security.UserGroupInformation: PriviledgedActionException as:yoonhok cause:java.io.FileNotFoundException: File /user/hive/warehouse/tbl_1/000000_0 does not exist.
13/02/17 16:23:09 ERROR tool.ExportTool: Encountered IOException running export job: java.io.FileNotFoundException: File /user/hive/warehouse/tbl_1/000000_0 does not exist.

当我检查 HDFS 时，文件存在:

When I check the HDFS, the file exists:

hadoop fs -ls /user/hive/warehouse/tbl_1
Found 1 items
-rw-r--r--   1 yoonhok supergroup        240 2013-02-16 18:56 /user/hive/warehouse/tbl_1/000000_0

如何在我的 Java 程序中执行 Sqoop?

How can I execute Sqoop in my Java program?

我尝试过 Processbuilder 和 Process，但我不想使用它们.

I tried Processbuilder and Process, but I don't want to use them.

我真的很想使用 Sqoop API，但我听说它还不存在.

I really want to use the Sqoop API, but I heard that it doesn't exist yet.

我阅读了这个问题，但它不适用于我.

I read this question but it doesn't work for me.

推荐答案

有一个技巧对我来说很容易解决.通过 ssh 可以直接执行 Sqoop 命令.只是你必须使用的是一个 SSH Java 库

There is a trick which worked out for me pretty easy. Via ssh you can execute Sqoop command directly. Just you have to use is a SSH Java Library

您必须遵循此步骤.

下载 sshxcute Java 库:https://code.google.com/p/sshxcute/并将其添加到包含以下java代码的java项目的构建路径

Download sshxcute java library : https://code.google.com/p/sshxcute/ and Add it to the build path of your java project which contains the following java code

import net.neoremind.sshxcute.core.SSHExec;
import net.neoremind.sshxcute.core.ConnBean;
import net.neoremind.sshxcute.task.CustomTask;
import net.neoremind.sshxcute.task.impl.ExecCommand;

public class TestSSH {

   public static void main(String args[]) throws Exception{

    // Initialize a ConnBean object, parameter list is ip, username, password

    ConnBean cb = new ConnBean("192.168.56.102", "root","hadoop");

    // Put the ConnBean instance as parameter for SSHExec static method getInstance(ConnBean) to retrieve a singleton SSHExec instance
    SSHExec ssh = SSHExec.getInstance(cb);          
    // Connect to server
    ssh.connect();
    CustomTask sampleTask1 = new ExecCommand("echo $SSH_CLIENT"); // Print Your Client IP By which you connected to ssh server on Horton Sandbox
    System.out.println(ssh.exec(sampleTask1));
    CustomTask sampleTask2 = new ExecCommand("sqoop import --connect jdbc:mysql://192.168.56.101:3316/mysql_db_name --username=mysql_user --password=mysql_pwd --table mysql_table_name --hive-import -m 1 -- --schema default");
    ssh.exec(sampleTask2);
    ssh.disconnect();   
   }
}

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