More Than Four

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Month: May 2017

Installing Oracle’s JDK in Ubuntu Linux

May 25, 2017 / / 0 Comments

Just for my own notes, because I can never remember this stuff.

1. Check the architecture of your host:

colin@Mongpy:~$ uname -m
x86_64

2. Grab the appropriate download from Oracle’s web site:

image

My web browser puts it in the Downloads folder under home.

colin@Mongpy:~$ ls -l ~/Downloads
total 393356
drwxr-sr-x 7 colin colin 4096 Mar 31 12:21 eclipse-installer
-rw-rw-r-- 1 colin colin 185540433 May 25 13:19 jdk-8u131-linux-x64.tar.gz
-rw-rw-r-- 1 colin colin 21944320 Mar 29 14:18 mysql-workbench-community-6.3.9-1ubuntu16.10-amd64.deb
-rw-rw-r-- 1 colin colin 195297254 May 25 12:47 pycharm-community-2017.1.3.tar.gz

3. Open a terminal and get superuser access:

colin@Mongpy:~$ sudo su
[sudo] password for colin:
root@Mongpy:/home/colin#

4. Make a directory and expand the archive:

root@Mongpy:/home/colin# mkdir /opt/jdk
root@Mongpy:/home/colin# tar -zxf ./Downloads/jdk-8u131-linux-x64.tar.gz -C /opt/jdk
root@Mongpy:/home/colin# ls -l /opt/jdk
total 4
drwxr-xr-x 8 uucp 143 4096 Mar 15 01:35 jdk1.8.0_131

5. Review the current default JDK:

root@Mongpy:~# update-alternatives --display java
java - auto mode
link best version is /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java
link currently points to /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java
link java is /usr/bin/java
slave java.1.gz is /usr/share/man/man1/java.1.gz
/usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java - priority 1081
slave java.1.gz: /usr/lib/jvm/java-8-openjdk-amd64/jre/man/man1/java.1.gz
 
root@Mongpy:~# update-alternatives --display javac
javac - auto mode
link best version is /usr/lib/jvm/java-8-openjdk-amd64/bin/javac
link currently points to /usr/lib/jvm/java-8-openjdk-amd64/bin/javac
link javac is /usr/bin/javac
slave javac.1.gz is /usr/share/man/man1/javac.1.gz
/usr/lib/jvm/java-8-openjdk-amd64/bin/javac - priority 1081
slave javac.1.gz: /usr/lib/jvm/java-8-openjdk-amd64/man/man1/javac.1.gz

Note the current “priority” is 1081.

6. Set the Oracle version as the default JDK, using a higher priority, say 1090:

root@Mongpy:/home/colin# update-alternatives --install /usr/bin/java java /opt/jdk/jdk1.8.0_131/bin/java 1090
 
update-alternatives: using /opt/jdk/jdk1.8.0_131/bin/java to provide /usr/bin/java (java) in auto mode
 
root@Mongpy:/home/colin# update-alternatives --install /usr/bin/javac javac /opt/jdk/jdk1.8.0_131/bin/javac 1090
 
update-alternatives: using /opt/jdk/jdk1.8.0_131/bin/javac to provide /usr/bin/javac (javac) in auto mode
 
root@Mongpy:/home/colin# update-alternatives --display java
java - auto mode
  link best version is /opt/jdk/jdk1.8.0_131/bin/java
  link currently points to /opt/jdk/jdk1.8.0_131/bin/java
  link java is /usr/bin/java
  slave java.1.gz is /usr/share/man/man1/java.1.gz
/opt/jdk/jdk1.8.0_131/bin/java - priority 1090
/usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java - priority 1081
  slave java.1.gz: /usr/lib/jvm/java-8-openjdk-amd64/jre/man/man1/java.1.gz
 
root@Mongpy:/home/colin# update-alternatives --display javac
javac - auto mode
  link best version is /opt/jdk/jdk1.8.0_131/bin/javac
  link currently points to /opt/jdk/jdk1.8.0_131/bin/javac
  link javac is /usr/bin/javac
  slave javac.1.gz is /usr/share/man/man1/javac.1.gz
/opt/jdk/jdk1.8.0_131/bin/javac - priority 1090
/usr/lib/jvm/java-8-openjdk-amd64/bin/javac - priority 1081
  slave javac.1.gz: /usr/lib/jvm/java-8-openjdk-amd64/man/man1/javac.1.gz

7. Finally, testing:

colin@Mongpy:~$ java -version
java version "1.8.0_131"
Java(TM) SE Runtime Environment (build 1.8.0_131-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.131-b11, mixed mode)

Cool.

MySQL notes

May 11, 2017 / / 0 Comments

The situation is that I have a MySQL database instance somewhere out on the network. And I’m trying to connect to it.

Logging in from the DB host

Plan:

  • Open a terminal window on the DB host, 192.168.1.130
  • Attempt to connect as the root db user
[root@zyxx01 ~]# mysql -u root
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

That didn’t work. This does, though:

[root@zyxx01 ~]# mysql -u root -p
Enter password: ****
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 171310
Server version: 5.5.32-log MySQL Community Server (GPL)
 
mysql>

So, don’t forget the -p option on the command-line. I guess that it tries first to connect without a password, which is a possible configuration for MySQL. And fails because it isn’t allowed in this instance.

Logging in from remote machine

My first attempt here didn’t work either, because “mysql” actually runs a batch file which expands into:

D:\>c:\progra~1\mysql\mysqls~1.5\bin\mysql.exe --defaults-file=c:\ProgramData\MySQL\mysqls~1.5\my.ini -uroot -p
Enter password: ********
ERROR 2003 (HY000): Can't connect to MySQL server on 'localhost' (10061)

Invoking the .exe directly avoids that interesting “defaults-file” thing:

D:\>c:\progra~1\mysql\mysqls~1.5\bin\mysql.exe -h 192.168.1.130 -u root -p
Enter password: ********
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 204151
Server version: 5.5.32-log MySQL Community Server (GPL)
 
Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.
 
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
 
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
 
mysql>

Cool, we’re in. So now, let’s create a user:

mysql> create user 'abacab'@'%' identified by '****';
Query OK, 0 rows affected (0.00 sec)
 
mysql> grant all privileges on *.* to 'abacab'@'%' ;
Query OK, 0 rows affected (0.00 sec)
 
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
 
mysql>

Testing the user:

D:\>c:\progra~1\mysql\mysqls~1.5\bin\mysql.exe -h 192.168.1.130 -u abacab -p
Enter password: ***********
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 206648
Server version: 5.5.32-log MySQL Community Server (GPL)
...
mysql>

Success.

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