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Install Sun/Oracle Java JDK/JRE 7 on Linux Fedora, CentOS/RHEL

This is a guide about how to Install Sun/Oracle Java JDK and JRE 7 update 2 (7u2) on Fedora 16, Fedora 15, Fedora 14, Fedora 13, Fedora 12, CentOS 6.1/6/5.7, Red Hat (RHEL) 6.1/6/5.7.

If you’re looking instruction for Sun/Oracle Java JDK/JRE version 6 installation on Fedora 16/15, CentOS/Red Hat (RHEL) 6.1/5.7, please check this guide.

What’s new in Sun/Oracle Java 7

  • VM
    • Compressed 64-bit object pointers
    • Garbage-First GC (G1)
    • JSR 292: VM support for non-Java languages (InvokeDynamic)
  • Lang
    • JSR 294: Language and VM support for modular programming
    • JSR 308: Annotations on Java types
    • JSR TBD: Small language enhancements (Project Coin)
    • JSR TBD: Project Lambda
  • Core
    • Modularization (Project Jigsaw)
    • Upgrade class-loader architecture
    • Method to close a URLClassLoader
    • Unicode 5.1
    • Concurrency and collections updates (jsr166y)
    • JSR 203: More new I/O APIs for the Java platform (NIO.2)
    • SCTP (Stream Control Transmission Protocol)
    • SDP (Sockets Direct Protocol)
    • Elliptic-curve cryptography (ECC)
  • Client
    • XRender pipeline for Java 2D
    • Forward-port 6u10 deployment features
    • Create new platform APIs for 6u10 graphics features
    • Nimbus look-and-feel for Swing
    • Swing JLayer component
  • Web
    • Update the XML stack

Read full info from here.

If you don’t know what is the difference between JRE, JVM and JDK, read here.

Install Sun/Oracle Java JDK/JRE 7u2 on Fedora 16/15/14/13/12, CentOS 6.1/6/5.7, Red Hat (RHEL) 6.1/6/5.7

1. Download Sun/Oracle Java JDK/JRE 7u2 32-bit/64-bit RPM packages

Download Sun/Oracle Java 7u2 from here http://www.oracle.com/technetwork/java/javase/downloads/index.html. Select rpm package (jdk-7u2-linux-i586.rpm, jdk-7u2-linux-x64.rpm, jre-7u2-linux-i586.rpm or jre-7u2-linux-x64.rpm).

2. Change to root user.

sudo -i
## OR ##
su -

3. Install Java JDK or JRE package

## JDK 32-bit ##
rpm -Uvh /path/to/binary/jdk-7u2-linux-i586.rpm

## JDK 64-bit ##
rpm -Uvh /path/to/binary/jdk-7u2-linux-x64.rpm

## JRE 32-bit ##
rpm -Uvh /path/to/binary/jre-7u2-linux-i586.rpm

## JRE 64-bit ##
rpm -Uvh /path/to/binary/jre-7u2-linux-x64.rpm

4a. Install Sun/Oracle JDK java, javaws, libjavaplugin.so (for Firefox/Mozilla) and javac with alternatives –install command

Use Java JDK latest version (/usr/java/latest)

## java ##
alternatives --install /usr/bin/java java /usr/java/latest/jre/bin/java 20000
## javaws ##
alternatives --install /usr/bin/javaws javaws /usr/java/latest/jre/bin/javaws 20000

## Java Browser (Mozilla) Plugin 32-bit ##
alternatives --install /usr/lib/mozilla/plugins/libjavaplugin.so libjavaplugin.so
/usr/java/latest/jre/lib/i386/libnpjp2.so 20000

## Java Browser (Mozilla) Plugin 64-bit ##
alternatives --install /usr/lib64/mozilla/plugins/libjavaplugin.so libjavaplugin.so.x86_64
/usr/java/latest/jre/lib/amd64/libnpjp2.so 20000

## Install javac only if you installed JDK (Java Development Kit) package ##
alternatives --install /usr/bin/javac javac /usr/java/latest/bin/javac 20000
alternatives --install /usr/bin/jar jar /usr/java/latest/bin/jar 20000

Use Java JDK absolute version (/usr/java/jdk1.7.0_02)

## java ##
alternatives --install /usr/bin/java java /usr/java/jdk1.7.0_02/jre/bin/java 20000
## javaws ##
alternatives --install /usr/bin/javaws javaws /usr/java/jdk1.7.0_02/jre/bin/javaws 20000

## Java Browser (Mozilla) Plugin 32-bit ##
alternatives --install /usr/lib/mozilla/plugins/libjavaplugin.so libjavaplugin.so
/usr/java/jdk1.7.0_02/jre/lib/i386/libnpjp2.so 20000

## Java Browser (Mozilla) Plugin 64-bit ##
alternatives --install /usr/lib64/mozilla/plugins/libjavaplugin.so libjavaplugin.so.x86_64
/usr/java/jdk1.7.0_02/jre/lib/amd64/libnpjp2.so 20000

## Install javac only if you installed JDK (Java Development Kit) package ##
alternatives --install /usr/bin/javac javac /usr/java/jdk1.7.0_02/bin/javac 20000
alternatives --install /usr/bin/jar jar /usr/java/jdk1.7.0_02/bin/jar 20000

4b. Install Sun/Oracle JRE java, javaws and libjavaplugin.so
(for Firefox/Mozilla) with alternatives –install command

Use Java JRE latest version (/usr/java/latest)

## java ##
alternatives --install /usr/bin/java java /usr/java/latest/bin/java 20000

## javaws ##
alternatives --install /usr/bin/javaws javaws /usr/java/latest/bin/javaws 20000

## Java Browser (Mozilla) Plugin 32-bit ##
alternatives --install /usr/lib/mozilla/plugins/libjavaplugin.so libjavaplugin.so
/usr/java/latest/lib/i386/libnpjp2.so 20000

## Java Browser (Mozilla) Plugin 64-bit ##
alternatives --install /usr/lib64/mozilla/plugins/libjavaplugin.so libjavaplugin.so.x86_64
/usr/java/latest/lib/amd64/libnpjp2.so 20000

Use Java JRE absolute version (/usr/java/jre1.7.0_02)

## java ##
alternatives --install /usr/bin/java java /usr/java/jre1.7.0_02/bin/java 20000

## javaws (32-bit only) ##
alternatives --install /usr/bin/javaws javaws /usr/java/jre1.7.0_02/bin/javaws 20000

## Java Browser (Mozilla) Plugin 32-bit ##
alternatives --install /usr/lib/mozilla/plugins/libjavaplugin.so libjavaplugin.so
/usr/java/jre1.7.0_02/lib/i386/libnpjp2.so 20000

## Java Browser (Mozilla) Plugin 64-bit ##
alternatives --install /usr/lib64/mozilla/plugins/libjavaplugin.so libjavaplugin.so.x86_64
/usr/java/jre1.7.0_02/lib/amd64/libnpjp2.so 20000

5. Check current java, javac, javaws and libjavaplugin.so versions

java -version
java version "1.7.0_02"
Java(TM) SE Runtime Environment (build 1.7.0_02-b13)
Java HotSpot(TM) 64-Bit Server VM (build 22.0-b10, mixed mode)

javaws
Java(TM) Web Start 1.7.0_02
[...]

javac -version
javac 1.7.0_02

Note: Check libjavaplugin.so with restarting Mozilla Firefox and writing about:plugins on address bar.

6. Swap between OpenJDK and Sun/Oracle Java JDK/JRE 6 and 7 versions

java

alternatives --config java

There are 5 programs which provide 'java'.

  Selection    Command
-----------------------------------------------
*  1           /usr/java/jdk1.6.0_24/jre/bin/java
   2           /usr/lib/jvm/jre-1.5.0-gcj/bin/java
 + 3           /usr/java/jdk1.6.0_26/jre/bin/java
   4           /usr/lib/jvm/jre-1.6.0-openjdk/bin/java
   5           /usr/java/jdk1.7.0_02/jre/bin/java

Enter to keep the current selection[+], or type selection number: 5

Note: java with [+] is currently on use

javaws

alternatives --config javaws

There are 3 programs which provide 'javaws'.

  Selection    Command
-----------------------------------------------
*  1           /usr/java/jdk1.6.0_24/jre/bin/javaws
 + 2           /usr/java/jdk1.6.0_26/jre/bin/javaws
   3           /usr/java/jdk1.7.0_02/jre/bin/javaws

Enter to keep the current selection[+], or type selection number: 3

Note: java with [+] is currently on use

libjavaplugin.so (32-bit)

alternatives --config libjavaplugin.so

There are 3 programs which provide 'libjavaplugin.so'.

  Selection    Command
-----------------------------------------------
*  1           /usr/java/jdk1.6.0_24/jre/lib/i386/libnpjp2.so
 + 2           /usr/java/jdk1.6.0_26/jre/lib/i386/libnpjp2.so
   3           /usr/java/jdk1.7.0_02/jre/lib/i386/libnpjp2.so

Enter to keep the current selection[+], or type selection number: 3

libjavaplugin.so.x86_64 (64-bit)

alternatives --config libjavaplugin.so.x86_64

There are 3 programs which provide 'libjavaplugin.so.x86_64'.

  Selection    Command
-----------------------------------------------
*  1           /usr/java/jdk1.6.0_24/jre/lib/amd64/libnpjp2.so
 + 2           /usr/java/jdk1.6.0_26/jre/lib/amd64/libnpjp2.so
   3           /usr/java/jdk1.7.0_02/jre/lib/amd64/libnpjp2.so

Enter to keep the current selection[+], or type selection number: 3

javac

alternatives --config javac

There are 3 programs which provide 'javac'.

  Selection    Command
-----------------------------------------------
*  1           /usr/java/jdk1.6.0_24/bin/javac
 + 2           /usr/java/jdk1.6.0_26/bin/javac
   3           /usr/java/jdk1.7.0_02/bin/javac

Enter to keep the current selection[+], or type selection number: 3

Note: java with [+] is currently on use

Post-Installation Setup

Add JAVA_HOME environment variable to /etc/profile file or $HOME/.bash_profile file

Java JDK and JRE latest version (/usr/java/latest)

## export JAVA_HOME JDK/JRE ##
export JAVA_HOME="/usr/java/latest"

Java JDK and JRE absolute version (/usr/java/jdk1.7.0_02)

## export JAVA_HOME JDK ##
export JAVA_HOME="/usr/java/jdk1.7.0_02"

## export JAVA_HOME JRE ##
export JAVA_HOME="/usr/java/jre1.7.0_02"
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PHP MySQL Update

The UPDATE statement is used to modify data in a table.


Update Data In a Database

The UPDATE statement is used to update existing records in a table.

Syntax

UPDATE table_name
SET column1=value, column2=value2,…
WHERE some_column=some_value

Note:Notice the WHERE clause in the UPDATE syntax. The WHERE clause specifies which record or records that should be updated. If you omit the WHERE clause, all records will be updated!

To learn more about SQL, please visit our SQL tutorial.

To get PHP to execute the statement above we must use the mysql_query() function. This function is used to send a query or command to a MySQL connection.

Example

Earlier in the tutorial we created a table named “Persons”. Here is how it looks:

FirstName LastName Age
Peter Griffin 35
Glenn Quagmire 33

The following example updates some data in the “Persons” table:

<?php
$con = mysql_connect(“localhost”,”peter”,”abc123″);
if (!$con)
{
die(‘Could not connect: ‘ . mysql_error());
}

mysql_select_db(“my_db”, $con);

mysql_query(“UPDATE Persons SET Age = ’36’
WHERE FirstName = ‘Peter’ AND LastName = ‘Griffin'”);

mysql_close($con);
?>

After the update, the “Persons” table will look like this:

FirstName LastName Age
Peter Griffin 36
Glenn Quagmire 33
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PHP MySQL The Where Clause

The WHERE clause is used to filter records.


The WHERE clause

The WHERE clause is used to extract only those records that fulfill a specified criterion.

Syntax

SELECT column_name(s)
FROM table_name
WHERE column_name operator value

To learn more about SQL, please visit our SQL tutorial.

To get PHP to execute the statement above we must use the mysql_query() function. This function is used to send a query or command to a MySQL connection.

Example

The following example selects all rows from the “Persons” table where “FirstName=’Peter’:

<?php
$con = mysql_connect(“localhost”,”peter”,”abc123″);
if (!$con)
{
die(‘Could not connect: ‘ . mysql_error());
}mysql_select_db(“my_db”, $con);

$result = mysql_query(“SELECT * FROM Persons
WHERE FirstName=’Peter'”);

while($row = mysql_fetch_array($result))
{
echo $row[‘FirstName’] . ” ” . $row[‘LastName’];
echo “<br />”;
}
?>

The output of the code above will be:

Peter Griffin
________________________________________________________

PHP MySQL Order By Keyword

The ORDER BY keyword is used to sort the data in a recordset.


The ORDER BY Keyword

The ORDER BY keyword is used to sort the data in a recordset.

The ORDER BY keyword sort the records in ascending order by default.

If you want to sort the records in a descending order, you can use the DESC keyword.

Syntax

SELECT column_name(s)
FROM table_name
ORDER BY column_name(s) ASC|DESC

To learn more about SQL, please visit our SQL tutorial.

Example

The following example selects all the data stored in the “Persons” table, and sorts the result by the “Age” column:

<?php
$con = mysql_connect(“localhost”,”peter”,”abc123″);
if (!$con)
{
die(‘Could not connect: ‘ . mysql_error());
}

mysql_select_db(“my_db”, $con);

$result = mysql_query(“SELECT * FROM Persons ORDER BY age”);

while($row = mysql_fetch_array($result))
{
echo $row[‘FirstName’];
echo ” ” . $row[‘LastName’];
echo ” ” . $row[‘Age’];
echo “<br />”;
}

mysql_close($con);
?>

The output of the code above will be:

Glenn Quagmire 33
Peter Griffin 35

 


Order by Two Columns

It is also possible to order by more than one column. When ordering by more than one column, the second column is only used if the values in the first column are equal:

SELECT column_name(s)
FROM table_name
ORDER BY column1, column2
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PHP MySQL Select

The SELECT statement is used to select data from a database.


Select Data From a Database Table

The SELECT statement is used to select data from a database.

Syntax

SELECT column_name(s)
FROM table_name

To learn more about SQL, please visit our SQL tutorial.

To get PHP to execute the statement above we must use the mysql_query() function. This function is used to send a query or command to a MySQL connection.

Example

The following example selects all the data stored in the “Persons” table (The * character selects all the data in the table):

<?php
$con = mysql_connect(“localhost”,”peter”,”abc123″);
if (!$con)
{
die(‘Could not connect: ‘ . mysql_error());
}

mysql_select_db(“my_db”, $con);

$result = mysql_query(“SELECT * FROM Persons”);

while($row = mysql_fetch_array($result))
{
echo $row[‘FirstName’] . ” ” . $row[‘LastName’];
echo “<br />”;
}

mysql_close($con);
?>

The example above stores the data returned by the mysql_query() function in the $result variable.

Next, we use the mysql_fetch_array() function to return the first row from the recordset as an array. Each call to mysql_fetch_array() returns the next row in the recordset. The while loop loops through all the records in the recordset. To print the value of each row, we use the PHP $row variable ($row[‘FirstName’] and $row[‘LastName’]).

The output of the code above will be:

Peter Griffin
Glenn Quagmire

 


Display the Result in an HTML Table

The following example selects the same data as the example above, but will display the data in an HTML table:

<?php
$con = mysql_connect(“localhost”,”peter”,”abc123″);
if (!$con)
{
die(‘Could not connect: ‘ . mysql_error());
}

mysql_select_db(“my_db”, $con);

$result = mysql_query(“SELECT * FROM Persons”);

echo <table border=’1′>
<
tr>
<th>Firstname</th>
<th>Lastname</th>
</tr>”;

while($row = mysql_fetch_array($result))
{
echo “<tr>”;
echo “<td>” . $row[‘FirstName’] . “</td>”;
echo “<td>” . $row[‘LastName’] . “</td>”;
echo “</tr>”;
}
echo “</table>”;

mysql_close($con);
?>

The output of the code above will be:

Firstname Lastname
Glenn Quagmire
Peter Griffin
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PHP MySQL Insert Into a Table

The INSERT INTO statement is used to insert new records in a table.


Insert Data Into a Database Table

The INSERT INTO statement is used to add new records to a database table.

Syntax

It is possible to write the INSERT INTO statement in two forms.

The first form doesn’t specify the column names where the data will be inserted, only their values:

INSERT INTO table_name
VALUES (value1, value2, value3,…)

The second form specifies both the column names and the values to be inserted:

INSERT INTO table_name (column1, column2, column3,…)
VALUES (value1, value2, value3,…)

To learn more about SQL, please visit our SQL tutorial.

To get PHP to execute the statements above we must use the mysql_query() function. This function is used to send a query or command to a MySQL connection.

Example

In the previous chapter we created a table named “Persons”, with three columns; “Firstname”, “Lastname” and “Age”. We will use the same table in this example. The following example adds two new records to the “Persons” table:

<?php
$con = mysql_connect(“localhost”,”peter”,”abc123″);
if (!$con)
{
die(‘Could not connect: ‘ . mysql_error());
}

mysql_select_db(“my_db”, $con);

mysql_query(“INSERT INTO Persons (FirstName, LastName, Age)
VALUES (‘Peter’, ‘Griffin’, ’35’)”);

mysql_query(“INSERT INTO Persons (FirstName, LastName, Age)
VALUES (‘Glenn’, ‘Quagmire’, ’33’)”);

mysql_close($con);
?>

 


Insert Data From a Form Into a Database

Now we will create an HTML form that can be used to add new records to the “Persons” table.

Here is the HTML form:

<html>
<body>

<form action=”insert.php” method=”post”>
Firstname: <input type=”text” name=”firstname” />
Lastname: <input type=”text” name=”lastname” />
Age: <input type=”text” name=”age” />
<input type=”submit” />
</form>

</body>
</html>

When a user clicks the submit button in the HTML form in the example above, the form data is sent to “insert.php”.

The “insert.php” file connects to a database, and retrieves the values from the form with the PHP $_POST variables.

Then, the mysql_query() function executes the INSERT INTO statement, and a new record will be added to the “Persons” table.

Here is the “insert.php” page:

<?php
$con = mysql_connect(“localhost”,”peter”,”abc123″);
if (!$con)
{
die(‘Could not connect: ‘ . mysql_error());
}

mysql_select_db(“my_db”, $con);

$sql=”INSERT INTO Persons (FirstName, LastName, Age)
VALUES
(‘$_POST[firstname]’,’$_POST[lastname]’,’$_POST[age]’)”;

if (!mysql_query($sql,$con))
{
die(‘Error: ‘ . mysql_error());
}
echo “1 record added”;

mysql_close($con)
?>

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Browser Evolution – The History of Web Browsers

Looking at the browsers in the current browser race it is hard to remember the time when Netscape had over 86% of the market share. Once Microsoft started integrating Internet Explorer with Windows they unsurprisingly took over the market and dominated it for several years. Now they have a few other new and powerful competitors. Enjoy this infographic and the The History of Web Browsers.

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How to dual boot Linux and Windows XP (Linux installed first)

A step-by-step guide with screenshots

(Now updated for XP SP 3 and Ubuntu 8.04.)

Step 1 Intro

Step 2 Back up the GRUB boot menu
Step 3 Make space for XP
Step 4 Install Windows XP
Step 5 Restore the GRUB boot loader

Step 1 – Intro

Scenario: You want to install XP on your machine alongside your existing Linux installation on the same physical drive which already has Ubuntu 8.04 installed.

Tutorial Summary: We’ll create space on the Linux partition to install Windows XP. XP bootloader is fairly clumsy when it comes to dualbooting and will overwrite GRUB completely. We’ll reinstall GRUB to the MBR and configure it to dualboot both Ubuntu and XP.

This tutorial has been tested on a VMWare Workstation 6.0.3 virtual machine.

Step 2 – Back up the GRUB boot menu

Regardless of which bootloader you end up using, it’s a very good move to first back up the GRUB bootloader. It’s easy to lose it and unless you know how to re-write it from scratch then you’re generally facing a full reinstallation of Ubuntu.

Firstly, boot into Ubuntu and go to Applications –> Accessories –> Terminal. Then, type in sudo gedit /boot/grub/menu.lst.

This text file contains all the information GRUB uses to configure various boot options. Scroll down and the entries between “## ## End Default Options ##” and “### END DEBIAN AUTOMATIC KERNELS LIST” are the Linux boot options.

Make a backup of the file by going to File, Save As and selecting a different location. Or take a full copy of the contents and place it into a new text file. If you can, create the backup on a removable disk or networked location.