PDF File Generation example in Java using iText Library

iText is an awesome library to work with for PDF manipulation which also gives complete support for its format. I made an example where reports can be generated in PDF file format using iText library for Java. I made a swing app and we enter the data and then click the create pdf button to generate the pdf. Its not a tutorial but more like an example with a demo. Use the code, and I hope its readable enough.

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Read Character Files line by line in Java version 6 or less

Duke, the Java Mascot, in the waving pose. Duke images are now Free Graphics see duke:Project Home Page for more details. (Photo credit: Wikipedia)

In this post I am sharing a code on how to read character files line by line for Java version 6 or less. The current java version being 8 and the way to read the files is a bit different, like we use Java NIO primarily. Still for the sake of knowledge this post will help you clear some concepts.

The following source shows you the way to read a file in Java version 6 or less (compatible with JDK 5 but not 4)

It covers most of the error handling cases possible and note that we should close BufferedReader when not in use. The following prints the time taken by the code to read the file and total number of the contents read (In this case I read a file containing all the words of a dictionary)

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Example of Path class in Java NIO

The Path class, introduced in the Java SE 7 release, is one of the primary entrypoints of the java.nio.file package. If your application uses file I/O, you will want to learn about the powerful features of this class.

A file system stores and organizes files on some form of media, generally one or more hard drives, in such a way that they can be easily retrieved. Most file systems in use today store the files in a tree (or hierarchical) structure. At the top of the tree is one (or more) root nodes. Under the root node, there are files and directories (folders in Microsoft Windows). Each directory can contain files and subdirectories, which in turn can contain files and subdirectories, and so on, potentially to an almost limitless depth.

What Is a Path?

The following figure shows a sample directory tree containing a single root node. Microsoft Windows supports multiple root nodes. Each root node maps to a volume, such as C:\ or D:\. The Solaris OS supports a single root node, which is denoted by the slash character, /.
Sample Directory Structure A file is identified by its path through the file system, beginning from the root node. For example, the statusReport file in the previous figure is described by the following notation in the Solaris OS:

/home/sally/statusReport

In Microsoft Windows, statusReport is described by the following notation:

C:\home\sally\statusReport

The character used to separate the directory names (also called the delimiter) is specific to the file system: The Solaris OS uses the forward slash (/), and Microsoft Windows uses the backslash slash (\).

Relative or Absolute?

A path is either relative or absolute. An absolute path always contains the root element and the complete directory list required to locate the file. For example, /home/sally/statusReport is an absolute path. All of the information needed to locate the file is contained in the path string.

A relative path needs to be combined with another path in order to access a file. For example, joe/foo is a relative path. Without more information, a program cannot reliably locate the joe/foo directory in the file system.

For More details on Path class or detailed tutorial Visit This Page

This post is not a tutorial but rather I have written down a code which uses Path and shows the output of its different methods. Here's the code :- 

Output

Returns the absolute path :-/home/psycho_coder/NetBeansProjects/Miscel/src/data/en
Returns Real Path with Sym Links removed :/home/psycho_coder/NetBeansProjects/Miscel/src/data/en
Returns the normalized path /home/psycho_coder/NetBeansProjects/Miscel/src/data/en
Returns the parent directory in which the file is present :/home/psycho_coder/NetBeansProjects/Miscel/src/data
Returns the root directory :/
Returns the file name :en
Number of Name elements in the path 7
Resolves the given path against this path's parent path:/home/psycho_coder/NetBeansProjects/Miscel/src/data/en
Returns a subpath of the main path :Miscel/src/data/en
Returns the File path in a URL format : file:///home/psycho_coder/NetBeansProjects/Miscel/src/data/en

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Write a File using Java NIO

The following example shows how to write a file using Java NIO. It creates a file named loginlist.txt, if the file already exists then it will remove it. The following code also generate random strings of arbitrary length. The strings are written in the following format :-

<Random Strings> : <Random Strings>

It writes 10 million entries and takes 32 seconds in my PC (Intel Core i3 2nd Gen, RAM - 4 GB) to complete and file size reaches to about 180 MB.

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